multidimensional exploratory analysis of a structural ... · ⇒ look for dimensions: reflecting...

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X. Bry I3M, Univ. Montpellier II T. Verron ITG - SEITA, Centre de recherche P. Redont I3M, Univ. Montpellier II Multidimensional Exploratory Analysis of a Structural Model using a general costructure criterion: THEME (THematic Equation Model Explorator)

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Page 1: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Etre cible nous monde - Roberto MATTA

X. Bry I3M, Univ. Montpellier IIT. Verron ITG - SEITA, Centre de recherche

P. Redont I3M, Univ. Montpellier II

Multidimensional Exploratory Analysis of a Structural Model

using a general costructure criterion:

THEME (THematic Equation Model Explorator)

Page 2: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Introducing the Data and Problem:

19Observations:Cigarettes

52 Variables:

9 var.Hoffmann smoke contents /ISO smoking

9 var.Hoffmann smoke contents /Intense smoking

3 var.Filterbehaviour / ISO smoking

3 var.Filtration/ ISO smoking

8 var.Tobacco Blend Combustion

5 var.Paper Combustion

15 var.Tobacco Blend Chemistry

Data:Data:

THEME - Bry, Redont, Verron; COMPSTAT 2010

Problem: Regulations → Hoffmann Compounds control ⇒ HC modeling

CIGARETTE SMOKE

Page 3: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Introducing the Data and Problem:

19Observations:Cigarettes

52 Variables:

9 var.Hoffmann smoke contents /ISO smoking

9 var.Hoffmann smoke contents /Intense smoking

3 var.Filterbehaviour / ISO smoking

3 var.Filtration/ ISO smoking

8 var.Tobacco Blend Combustion

5 var.Paper Combustion

15 var.Tobacco Blend Chemistry

Data:Data:

THEME - Bry, Redont, Verron; COMPSTAT 2010

Problem: Regulations → Hoffmann Compounds control ⇒ HC modeling

⇒ Dimension reduction in groups⇒ Look for dimensions: reflecting their group's structure

& interpretable with respect to their theme

2) Many (redundant) variables

1) The thematic partitioning of variables must be kept (to separate roles, and keep explanatory)

Page 4: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Introducing the Data and Problem:

Dependency network of Data:Dependency network of Data:

THEME - Bry, Redont, Verron; COMPSTAT 2010

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

Thematic (conceptual) model Model design motivations:

Equation 1:

Hoffmann compounds are generated / transferred to smoke through combustion. Filter only plays a retention role (pores blocked in intense mode)

Equation 2:

Final output of Hoffmann compounds is conditioned by other filter properties, as ventilation/dilution.

Page 5: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Introducing the Data and Problem:

Dependency network of Data:Dependency network of Data:

⇒ Structural dimensions should be informative with respect to the model too

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

Thematic (conceptual) model

1) How many dimensions do play a proper role? 2) Which?

THEME - Bry, Redont, Verron; COMPSTAT 2010

Model design motivations:

Equation 1:

Hoffmann compounds are generated / transferred to smoke through combustion. Filter only plays a retention role (pores blocked in intense mode)

Equation 2:

Final output of Hoffmann compounds is conditioned by other filter properties, as ventilation/dilution.

Page 6: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

● Residual Sum of Squares → Multiblock Multiway Components and Covariates Regression Models (Smilde, Westerhuis, Bocqué 2000)Generalized structured component analysis (Hwang, Takane, 2004).

➔ Model residuals need weighting: How?

➔ The Methods do not extend PLS Regression to K Predictor Groups.

➔ Convergence problems in case of collinearity (small samples)

Path modeling methods optimizing a criterion:

RSS =

<X1>

<Y>

<X2>

RSS(group models) + RSS(component-based model)

based on a covariance criterion...

(minimized via Alternated Least Squares)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Likelihood → LISREL (Jöreskog 1975-2002)

Page 7: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of all variances

Linear Model Fit

● Multiple Covariance (Bry, Verron, Cazes 2009)y being linearly modeled as a function of x1,..., xS, Multiple Covariance of y on x1,..., xS is:

MC y∣x1 ,... , xS = [V y ∏s=1

S

V xsR2 y∣x1 , ... , xS ]12

maxv , u1 ,... , uR

∥v∥2=1∀ r ,∥ur∥

2=1

MC2Yv∣X 1 u1 , ... , X R uR

● Use for single « equation » structural model estimation: SEER (Bry, Verron, Cazes 2009)

f1 fR

g

X1

...

XR

Y

➢ One component per group:g | f1 , … , fR

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 8: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of all variances

Linear Model Fit

● Multiple Covariance (Bry, Verron, Cazes 2009)y being linearly modeled as a function of x1,..., xS, Multiple Covariance of y on x1,..., xS is:

MC y∣x1 ,... , xS = [V y ∏s=1

S

V xsR2 y∣x1 , ... , xS ]12

● Use for single « equation » structural model estimation: SEER (Bry, Verron, Cazes 2009)

f1 fR

g

X1

...

XR

Y

➢ One component per group:g | f1 , … , fR

maxv , u1 ,... , uR

∥v∥2=1∀ r ,∥ur∥

2=1

MC2Yv∣X 1 u1 , ... , X R uR

THEME - Bry, Redont, Verron; COMPSTAT 2010

→ The weighting of Groups is naturally balanced

→ The Method extends PLS Regression to K Predictor Groups

∇ log MC2=0 ⇔ relative variations compensate

Page 9: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of all variances

Linear Model Fit

● Multiple Covariance (Bry, Verron, Cazes 2009)y being linearly modeled as a function of x1,..., xS, Multiple Covariance of y on x1,..., xS is:

MC y∣x1 ,... , xS = [V y ∏s=1

S

V xsR2 y∣x1 , ... , xS ]12

→ The weighting of Groups is naturally balanced

→ The Method extends PLS Regression to K Predictor Groups

∇ log MC2=0 ⇔ relative variations compensate

● Use for single « equation » structural model estimation: SEER (Bry, Verron, Cazes 2009)

f1 fR

g

X1

...

XR

Y

➢ One component per group:g | f1 , … , fR

maxv , u1 ,... , uR

∥v∥2=1∀ r ,∥ur∥

2=1

MC2Yv∣X 1 u1 , ... , X R uR

➢ Several components per group: → Model Local Nesting Principle: Xr's components fr1 , fr

2...

are mutually ⊥ and calculated sequentially in one batch, controlling for all components in the other groups

1⊥… fR K

1⊥ … g L

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 10: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of all variances

Linear Model Fit

● Multiple Covariance (Bry, Verron, Cazes 2009)y being linearly modeled as a function of x1,..., xS, Multiple Covariance of y on x1,..., xS is:

MC y∣x1 ,... , xS = [V y ∏s=1

S

V xsR2 y∣x1 , ... , xS ]12

→ The weighting of Groups is naturally balanced

→ The Method extends PLS Regression to K Predictor Groups

∇ log MC2=0 ⇔ relative variations compensate

● Use for single « equation » structural model estimation: SEER (Bry, Verron, Cazes 2009)

f1 fR

g

X1

...

XR

Y

➢ One component per group:g | f1 , … , fR

maxv , u1 ,... , uR

∥v∥2=1∀ r ,∥ur∥

2=1

MC2Yv∣X 1 u1 , ... , X R uR

➢ Several components per group: → Model Local Nesting Principle: Xr's components fr1 , fr

2...

are mutually ⊥ and calculated sequentially in one batch, controlling for all components in the other groups

1⊥… fR K

1⊥ … g L

1⊥ f12

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 11: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of all variances

Linear Model Fit

● Multiple Covariance (Bry, Verron, Cazes 2009)y being linearly modeled as a function of x1,..., xS, Multiple Covariance of y on x1,..., xS is:

MC y∣x1 ,... , xS = [V y ∏s=1

S

V xsR2 y∣x1 , ... , xS ]12

→ The weighting of Groups is naturally balanced

→ The Method extends PLS Regression to K Predictor Groups

∇ log MC2=0 ⇔ relative variations compensate

● Use for single « equation » structural model estimation: SEER (Bry, Verron, Cazes 2009)

f1 fR

g

X1

...

XR

Y

➢ One component per group:g | f1 , … , fR

maxv , u1 ,... , uR

∥v∥2=1∀ r ,∥ur∥

2=1

MC2Yv∣X 1 u1 , ... , X R uR

➢ Several components per group: → Model Local Nesting Principle: Xr's components fr1 , fr

2...

are mutually ⊥ and calculated sequentially in one batch, controlling for all components in the other groups

1⊥… fR K

1⊥ … g L

1⊥ f12⊥ ...

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 12: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Beyond Covariance: Costructure

➢ Broadened approach to structural strength

Bundle A

Bundle B

Predictor space <X>

Extending covariance

Page 13: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Beyond Covariance: Costructure

➢ Broadened approach to structural strengthPC1

PC2Bundle A

Bundle B

Extending covariancePredictor space <X>

Page 14: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Beyond Covariance: Costructure

➢ Broadened approach to structural strength

OLS predictor

PC1

PC2Bundle A

Bundle B

Extending covariancePredictor space <X>

Page 15: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Beyond Covariance: Costructure

➢ Broadened approach to structural strength

OLS predictor

PC1

PC2Bundle A

Bundle B

original THEME predictor

Extending covariancePredictor space <X>

Page 16: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Beyond Covariance: Costructure

➢ Broadened approach to structural strength

OLS predictor

PC1

PC2Bundle A

Bundle B

original THEME predictor

Extending covariancePredictor space <X>

➢ General Costructure Criterion

S ur= ∑h=1, H

ur ' Ah ura

a = bundle focus parameter

∀ component fr = Xrur , V(fr) = ur'Xr'PXrur is replaced by:

Page 17: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Beyond Covariance: Costructure

➢ Broadened approach to structural strength

OLS predictor

PC1

PC2Bundle A

Bundle B

original THEME predictor

OLS predictor

PC1

PC2Bundle A

Bundle B

extended THEME predictor: drawn towards local bundle

Extending covariancePredictor space <X>

Predictor space <X>

➢ General Costructure Criterion

S ur= ∑h=1, H

ur ' Ah ura

a = bundle focus parameter

∀ component fr = Xrur , V(fr) = ur'Xr'PXrur is replaced by:

Page 18: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of stuctural strength measures

Linear Model Fit

● Multiple Co-structure:

Yv being linearly modeled as a function of X1u1,..., XRuR , Multiple Costructure of Yv on X1u1,..., XRuR  is:

MCS 2Yv∣X 1 u1 ,... , X R uR = S v ∏r=1

R

S usR2Yv∣X 1 u1 ,... , X R uR

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 19: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Extending covariance

Product of stuctural strength measures

Linear Model Fit

● Multiple Co-structure:

MCS 2Yv∣X 1 u1 ,... , X R uR = S v ∏r=1

R

S usR2Yv∣X 1 u1 ,... , X R uR

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Extended Multiple Co-structure:

Let F = {f k = Xuk ; k = 1, K} and G = {gj = Yvj; j = 1, J} be two variable groups. Square Extended Multiple Costructure of F (powered by γ) and G (powered by δ) is:

Product of stuctural strength measures

Linear Model Fit

EMC² F , ;G ,=∏k=1

K

S uk

∏j=1

J

S v j⟨F∣G⟩

KJ

Yv being linearly modeled as a function of X1u1,..., XRuR , Multiple Costructure of Yv on X1u1,..., XRuR  is:

Page 20: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

Predictive DependentGroups

EquationsX1 X2 X3 X4 X5 X6 X7 X1 X2 X3 X4 X5 X6 X7

1 × × × × ×2 × × ×

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

● System Multiple Covariance Criterion:

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 21: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

Predictive DependentGroups

EquationsX1 X2 X3 X4 X5 X6 X7 X1 X2 X3 X4 X5 X6 X7

1 × × × × ×2 × × ×

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

S(u1) … S(u4) S(u7) R²(X7u7 | X1u1, …X4u4)

EMC² (γ = δ = 1)

S(u5) S(u6) S(u7) R²(X6u6 | X5u5, X7u7)

● System Multiple Covariance Criterion:

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 22: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

Predictive DependentGroups

EquationsX1 X2 X3 X4 X5 X6 X7 X1 X2 X3 X4 X5 X6 X7

1 × × × × ×2 × × ×

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

S(u1) … S(u4) S(u5) S(u6) (S(u7))² × R²(X7u7 | X1u1, …X4u4)× R²(X6u6 | X5u5, X7u7)C = ∏

eEMC2Eq. e = ∏

r=1

R

S urqr∏e

R2Eq. e

# of equations involving group Xr

● System Multiple Covariance Criterion:

THEME - Bry, Redont, Verron; COMPSTAT 2010

S(u1) … S(u4) S(u7) R²(X7u7 | X1u1, …X4u4)

EMC² (γ = δ = 1)

S(u5) S(u6) S(u7) R²(X6u6 | X5u5, X7u7)

Page 23: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Maximizing the Global Multiple Covariance Criterion: maxu1 , ... , u R

∀ r ,∥ur∥2=1

C

C maximized iteratively on each ur in turn until convergence

⇔ maxur / ∥ur∥

2=1C ur = S urqr ∏

Eq. h involving X r

R2h

Page 24: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

∑h=1, H

ur ' S h ura

THEME - Bry, Redont, Verron; COMPSTAT 2010

● Maximizing the Global Multiple Covariance Criterion: maxu1 , ... , u R

∀ r ,∥ur∥2=1

C

C maximized iteratively on each ur in turn until convergence

⇔ maxur / ∥ur∥

2=1C ur = S urqr ∏

Eq. h involving X r

R2h

Page 25: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

∑h=1, H

ur ' S h ura

THEME - Bry, Redont, Verron; COMPSTAT 2010

Xr dependent

R2h=ur ' X r ' F r

h X rur

ur ' X r ' X rur

where Fh = components predictive in equation h

● Maximizing the Global Multiple Covariance Criterion: maxu1 , ... , u R

∀ r ,∥ur∥2=1

C

C maximized iteratively on each ur in turn until convergence

⇔ maxur / ∥ur∥

2=1C ur = S urqr ∏

Eq. h involving X r

R2h

Page 26: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

∑h=1, H

ur ' S h ura

THEME - Bry, Redont, Verron; COMPSTAT 2010

Xr dependent

R2h=ur ' X r ' F r

h X rur

ur ' X r ' X rur

where Fh = components predictive in equation h

● Maximizing the Global Multiple Covariance Criterion: maxu1 , ... , u R

∀ r ,∥ur∥2=1

C

C maximized iteratively on each ur in turn until convergence

⇔ maxur / ∥ur∥

2=1C ur = S urqr ∏

Eq. h involving X r

R2h

Xr predictor of Xd

R2h=ur ' X r ' Arh X rur

ur ' X r ' B rh X rur

Brh=F h −r ⊥

Arh =1

∥ f d∥2 [ f d ' F h −r f d BrhB rh ' f r f r ' B rh]

Page 27: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

∑h=1, H

ur ' S h ura

THEME - Bry, Redont, Verron; COMPSTAT 2010

Xr dependent

R2h=ur ' X r ' F r

h X rur

ur ' X r ' X rur

where Fh = components predictive in equation h

● Maximizing the Global Multiple Covariance Criterion: maxu1 , ... , u R

∀ r ,∥ur∥2=1

C

C maximized iteratively on each ur in turn until convergence

⇔ maxur / ∥ur∥

2=1C ur = S urqr ∏

Eq. h involving X r

R2h

Xr predictor of Xd

R2h=ur ' X r ' Arh X rur

ur ' X r ' B rh X rur

Brh=F h −r ⊥

Arh =1

∥ f d∥2 [ f d ' F h −r f d BrhB rh ' f r f r ' B rh]

→ Generic form of C(ur) : C ur= ∑h=1,Hur ' Sh ur

ar∏

l=1

qr ur ' T rlur

ur ' W rl ur

Page 28: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model➢ Generic program : P : max

ur / ∥ur∥2=1

C u= ∑h=1, Hu ' S h ua

∏l=1

q u ' T l uu ' W l u

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 29: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

S : minu≠0

u where: u=12[a u ' u− lnC v ]

➢ Equivalent unconstrained program :

→ General minimization software can / should be used

THEME - Bry, Redont, Verron; COMPSTAT 2010

➢ Generic program : P : maxur / ∥ur∥

2=1C u= ∑h=1, H

u ' S h ua

∏l=1

q u ' T l uu ' W l u

Page 30: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

→ Alternative specific algorithm: ∇u =0

⇔ u=[a I∑l=1

q W l

u ' W l u ]−1[a∑h

u ' S hua−1 S h

∑hu ' S hu

a ∑l=1

q T l

u ' T lu ]usuggesting the fixed point algorithm:

⇔ u t1=u t − [a I∑l=1

q W l

ut ' W l u t ]−1

∇u t (1)

u t1=[a I∑l=1

q W l

u t ' W l u t ]−1[a

∑hut ' S hu t a−1 Sh

∑hut ' Sh u t a ∑

l=1

q T l

u t ' T l ut ]u t

➢ Generic program : P : maxur / ∥ur∥

2=1C u= ∑h=1, H

u ' S h ua

∏l=1

q u ' T l uu ' W l u

S : minu≠0

u where: u=12[a u ' u− lnC v ]

➢ Equivalent unconstrained program :

→ General minimization software can / should be used

Page 31: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

➢ Generic program : P : maxur / ∥ur∥

2=1C u= ∑h=1, H

u ' S h ua

∏l=1

q u ' T l uu ' W l u

S : minu≠0

u where: u=12[a u ' u− lnC v ]

➢ Equivalent unconstrained program :

→ General minimization software can / should be used → Alternative specific algorithm: ∇u =0

⇔ u=[a I∑l=1

q W l

u ' W l u ]−1[a∑h

u ' S hua−1 S h

∑hu ' S hu

a ∑l=1

q T l

u ' T lu ]u

descent direction d(t)

suggesting the fixed point algorithm:

⇔ u t1=u t − [a I∑l=1

q W l

ut ' W l u t ]−1

∇u t (1)

u t1=[a I∑l=1

q W l

u t ' W l u t ]−1[a

∑hut ' S hu t a−1 Sh

∑hut ' Sh u t a ∑

l=1

q T l

u t ' T l ut ]u t

Page 32: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

➢ Generic program : P : maxur / ∥ur∥

2=1C u= ∑h=1, H

u ' S h ua

∏l=1

q u ' T l uu ' W l u

S : minu≠0

u where: u=12[a u ' u− lnC v ]

➢ Equivalent unconstrained program :

→ General minimization software can / should be used → Alternative specific algorithm: ∇u =0

⇔ u=[a I∑l=1

q W l

u ' W l u ]−1[a∑h

u ' S hua−1 S h

∑hu ' S hu

a ∑l=1

q T l

u ' T lu ]u

descent direction d(t)

suggesting the fixed point algorithm:

⇔ u t1=u t − [a I∑l=1

q W l

ut ' W l u t ]−1

∇u t (1)

u t1=[a I∑l=1

q W l

u t ' W l u t ]−1[a

∑hut ' S hu t a−1 Sh

∑hut ' Sh u t a ∑

l=1

q T l

u t ' T l ut ]u t

● Numerous simulations → (almost) always global minimum● (1) numerically faster than classical gradient descent.

h(t) = 1 works, but using h(t) > 0 improves convergence rate.If chosen according to the Wolfe, or Goldstein-Price, rule: convergence to critical point guaranteed.

h(t)

Page 33: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

● What if we want several components per group?

➢ Kr given ; Xr → {fr1 , fr

2... frKr} mutually ⊥

Page 34: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

● What if we want several components per group?

➢ Kr given ; Xr → {fr1 , fr

2... frKr} mutually ⊥

Model Local Nesting Principle:

fr1 calculated, all components in the other groups considered given;

→ Xr1 = Xr - (1/|| fr

1 ||) fr1fr

1' Xr = group of residuals of Xr regressed on fr1

fr2 calculated with group Xr

1 , all components in the other groups considered given, plus fr1 ;

→ Xr2 = Xr

1 - (1/|| fr2 ||) fr

2fr2' Xr

1 = group of residuals of Xr regressed on { fr1 , fr

2 }etc.

Page 35: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

● What if we want several components per group?

➢ Kr given ; Xr → {fr1 , fr

2... frKr} mutually ⊥

Model Local Nesting Principle:

fr1 calculated, all components in the other groups considered given;

→ Xr1 = Xr - (1/|| fr

1 ||) fr1fr

1' Xr = group of residuals of Xr regressed on fr1

fr2 calculated with group Xr

1 , all components in the other groups considered given, plus fr1 ;

→ Xr2 = Xr

1 - (1/|| fr2 ||) fr

2fr2' Xr

1 = group of residuals of Xr regressed on { fr1 , fr

2 }etc.

➢ Finding good Kr values through backward selection:

Starting with large Kr's → concentrating on “proper” effects→ Kr's maybe too large! (over-fitting, on structurally weak dimensions... up to noise).

Page 36: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Exploring a Multiple Component Equation Model

THEME - Bry, Redont, Verron; COMPSTAT 2010

● What if we want several components per group?

➢ Kr given ; Xr → {fr1 , fr

2... frKr} mutually ⊥

Model Local Nesting Principle:

fr1 calculated, all components in the other groups considered given;

→ Xr1 = Xr - (1/|| fr

1 ||) fr1fr

1' Xr = group of residuals of Xr regressed on fr1

fr2 calculated with group Xr

1 , all components in the other groups considered given, plus fr1 ;

→ Xr2 = Xr

1 - (1/|| fr2 ||) fr

2fr2' Xr

1 = group of residuals of Xr regressed on { fr1 , fr

2 }etc.

→ Problem: given estimated model with (K1, … , KR) components: which of the Kr-rank components could / should we preferably remove?

i.e. with the smallest possible drop in...

predictive power?

explanatory power?

the global criterion?

Cross-validation error-rateInterpretability

“technically” handy

➢ Finding good Kr values through backward selection:

Starting with large Kr's → concentrating on “proper” effects→ Kr's maybe too large! (over-fitting, on structurally weak dimensions... up to noise).

Page 37: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Numeric experiments

THEME - Bry, Redont, Verron; COMPSTAT 2010

Parameter values: a = 2, α = q = 2;Size 100 × 100 s.d.p. matrices with various eigenvalues patterns , 50 times, with 50 starting points.

→ There are local maxima, but a seemingly global maximum is reached most of the time.

Experiments:

Page 38: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Numeric experiments

THEME - Bry, Redont, Verron; COMPSTAT 2010

(1) Standard maximization subroutines ... - demand gradient threshold not too low (flat limit of function makes the routine oversensitive to calculus error noise)

(2) Fixed point algorithm (h = 1): no problem encountered ;- may reach arbitrary low gradient;- 2 to 3 times slower than (1).

(3) h optimized through Wolfe rule: - theoretical safeguard... useless in practice; - demanding a too low gradient results in instability in certain cases.

Parameter values: a = 2, α = q = 2;Size 100 × 100 s.d.p. matrices with various eigenvalues patterns , 50 times, with 50 starting points.

→ There are local maxima, but a seemingly global maximum is reached most of the time.

Compared performance of the three maximization methods

Slower, but more Robust

Experiments:

Page 39: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Application to cigarette dataTHEME - Bry, Redont, Verron; COMPSTAT 2010

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

● Initially: K = 3 components per group

● Remove rank Kr component alternately in each (predictor) group Xr

→ 6 « shrunk » models → Evaluated via cross-validation → Best model selected.

● Resume with selected model

Triple sample:- Calibration- Test & selection- Validation

Multiple Covariance criterion

Page 40: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

● Initially: K = 3 components per group

● Remove rank Kr component alternately in each (predictor) group Xr

→ 6 « shrunk » models → Evaluated via cross-validation → Best model selected.

● Resume with selected model

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

10%20%

30%40%

50%

CV eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_10%

20%40%60%80%

100%120%

R2 eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1

Application to cigarette dataMultiple Covariance criterion

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 41: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

● Initially: K = 3 components per group

● Remove rank Kr component alternately in each (predictor) group Xr

→ 6 « shrunk » models → Evaluated via cross-validation → Best model selected.

● Resume with selected model

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

10%20%

30%40%

50%

CV eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_10%

20%40%60%80%

100%120%

R2 eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1M

odel

1 3

_3_3

_3_3

_3_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%10%20%30%40%50%60%

CV eq.2

NFDPM 2 Nicotine 2 CO 2 Acetaldehyde 2Acrolein 2 Formaldehyde 2 BaP 2 NNK 2NNN 2 moy eq.2

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%20%40%60%80%

100%120%

R2 eq.2

NFDPM 2 Nicotine 2 CO 2 Acetaldehyde 2Acrolein 2 Formaldehyde 2 BaP 2 NNK 2NNN 2 moy eq.2

Application to cigarette dataMultiple Covariance criterion

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 42: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

● Initially: K = 3 components per group

● Remove rank Kr component alternately in each (predictor) group Xr

→ 6 « shrunk » models → Evaluated via cross-validation → Best model selected.

● Resume with selected model

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

10%20%

30%40%

50%

CV eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_10%

20%40%60%80%

100%120%

R2 eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1M

odel

1 3

_3_3

_3_3

_3_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%10%20%30%40%50%60%

CV eq.2

NFDPM 2 Nicotine 2 CO 2 Acetaldehyde 2Acrolein 2 Formaldehyde 2 BaP 2 NNK 2NNN 2 moy eq.2

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%20%40%60%80%

100%120%

R2 eq.2

NFDPM 2 Nicotine 2 CO 2 Acetaldehyde 2Acrolein 2 Formaldehyde 2 BaP 2 NNK 2NNN 2 moy eq.2M

odel

1 3

_3_3

_3_3

_3_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

5%

10%

15%

20%

25%

CV

moy eq.1 moy eq.2 MOY

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

20%

40%

60%

80%

100%

120%

R2

moy eq.1 moy eq.2 MOY

Application to cigarette dataMultiple Covariance criterion

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 43: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

X1: Tob Ch

X2: Cb Pap

X3: Cb Blend

X4: Cb Fil

X5: Fil Iso

X7: Hoff Int

X6: Hoff Iso

Equation 2

Equation 1

● Initially: K = 3 components per group

● Remove rank Kr component alternately in each (predictor) group Xr

→ 6 « shrunk » models → Evaluated via cross-validation → Best model selected.

● Resume with selected model

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

10%20%

30%40%

50%

CV eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_10%

20%40%60%80%

100%120%

R2 eq.1

NFDPM 1 Nicotine 1 CO 1 Acetaldehyde 1Acrolein 1 Formaldehyde 1 BaP 1 NNK 1NNN 1 moy eq.1M

odel

1 3

_3_3

_3_3

_3_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%10%20%30%40%50%60%

CV eq.2

NFDPM 2 Nicotine 2 CO 2 Acetaldehyde 2Acrolein 2 Formaldehyde 2 BaP 2 NNK 2NNN 2 moy eq.2

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%20%40%60%80%

100%120%

R2 eq.2

NFDPM 2 Nicotine 2 CO 2 Acetaldehyde 2Acrolein 2 Formaldehyde 2 BaP 2 NNK 2NNN 2 moy eq.2M

odel

1 3

_3_3

_3_3

_3_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

5%

10%

15%

20%

25%

CV

moy eq.1 moy eq.2 MOY

Mod

el 1

3_3

_3_3

_3_3

_3

Mod

el 2

2_3

_3_3

_3_3

_3

Mod

el 3

2_3

_2_3

_3_3

_3

Mod

el 4

2_2

_2_3

_3_3

_3

Mod

el 5

2_1

_2_3

_3_3

_3

Mod

el 6

2_1

_2_3

_2_3

_3

Mod

el 7

2_1

_2_2

_2_3

_3

Mod

el 8

1_1

_2_2

_2_3

_3

Mod

el 9

1_1

_2_1

_2_3

_3

Mod

el 1

0 1_

1_1_

1_2_

3_3

Mod

el 1

1 1_

0_1_

1_2_

3_3

Mod

el 1

2 1_

0_0_

1_2_

3_3

Mod

el 1

3 1_

0_0_

1_1_

3_3

Mod

el 1

4 1_

0_0_

1_1_

3_2

Mod

el 1

5 1_

0_0_

1_1_

3_1

0%

20%

40%

60%

80%

100%

120%

R2

moy eq.1 moy eq.2 MOY

→ Models 5, 6, 7

Model 72 2

1

2

2

3

3

Application to cigarette dataMultiple Covariance criterion

THEME - Bry, Redont, Verron; COMPSTAT 2010

Page 44: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Application to cigarette data

THEME - Bry, Redont, Verron; COMPSTAT 2010

axis 1

axis

2

-7 -5 -3 -1 1 3 5

-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.53.0 1

23

456

78

910

1112

1314

1516

17

18

19

Tobacco Chem (X1)observations

Tobacco Chem (X1)variables

axis 1: Tobacco Type

axis

2: T

obac

co Q

ualit

y

C_TO

Mal_TO

N_TOPP_TO

MV_TO

Asp_TO

Cit_TO

NO3_TO

Alka_TO

GFS_TO

NH3_TONAB_TONAT_TO

NNK_TO

NNN_TO

Flue

C

ured

Burle

y

Stalk position

Cutters dominant

Strips dominant

axis 1

axis

2

-2 -1 0 1 2 3 4 5

-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.5

1

2

3

4

5 6

78

9

10

1112 13

14

15

16

17

18

19

Blend combustion (X3)observations

Blend combustion (X3)variables

axis 1

axi

s 2

Lower burning process

Mg_Ca_pc

Cl_TOPO4_TO

K_pc_TO

Hg_TOPb_TO

Cd_TO

NO3_TO.1

accelerators

burning process

Filter combustion (X4)variables

axis 1:

axis

2:

Retention power

FDENSC

HC_BIN

PDEF

-1.5 -0.5 0.5 1.5 2.5

-2.0-1.5-1.0-0.50.00.51.01.52.0

1

2

3

4

56

7

8

91011

12

13

14

15

16

17

18

19

Filter combustion (X4)observations

axis 1

axis

2

Filter in ISO mode (X5)variables

axis 1:

axis

2:

FV

PD

PDFNE

Filter in ISO mode (X5)observations

axis 1:

axis

2:

-2.0 -1.0 0.0 1.0 2.0

-1.5-1.0-0.50.00.51.01.5

2.0 1

2

3

4

5

67

89

10

1112

13

1415

16

17

18

19

Component-planes for exogenous groups (model 7)

Page 45: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Application to cigarette data

THEME - Bry, Redont, Verron; COMPSTAT 2010

Hoffmann Intense (X7)variables

axis 1

axis

2

NFDPM.1NICO.1

CO.1Acetal.1

Acro.1

Fo.1

BaP.1

NNK.1NNN.1

Hoffmann Intense (X7)observations

axis 1-5 -3 -1 0 1 2 3 4 5

-2.0-1.5-1.0-0.50.00.51.01.52.02.5

1

2

3

4

5

6

7

8

9

10

1112

13

14

15

16

17

18

19

axis

2

Hoffmann ISO (X6)variables

axis 1

axis

2

NFDPM.2NICO.2

CO.2Acetal.2Acro.2

Fo.2

BaP.2

NNK.2

NNN.2

Hoffmann ISO (X6)observations

axis 1a

xis

2

-4 -3 -2 -1 0 1 2 3 4

-2.5-2.0-1.5-1.0-0.50.00.51.01.52.0

1

2

3

4

56 7

8

9101112

13

14 1516

17

18

19

Component-planes for dependent groups (model 7)

Hoffmann Intense (X7)variables

axis 1

axis

3

NFDPM.1

NICO.1

CO.1Acetal.1Acro.1

Fo.1

BaP.1

NNK.1NNN.1

-2.5-2.0-1.5-1.0

Hoffmann Intense (X7)observations

axis 1

axis

3

-5 -3 -1 0 1 2 3 4 5

-0.50.00.51.01.52.0

1

23

4

567

8

9

10

11 12

13

14

15

16

1718

19

● Roughly similar structures of predicted Hoffmann compounds in Intense and ISO modes.

● Positive correlation of all compounds reflects the filter ventilation effect.

● NNK and NNN are strongly related to tobacco type.

Page 46: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Application to cigarette data

THEME - Bry, Redont, Verron; COMPSTAT 2010

. * ** ***

NFDPM Nicotine CO NNK NNNF1 0,03 -0,09 0,24 0,13 0,21 0,28 0,02 -0,40 -0,32F2 -0,22 -0,64 0,34 0,26 0,48 0,00 -0,53 -0,21 0,06F1 -0,19 -0,28 0,09 -0,06 -0,06 -0,10 -0,27 -0,47 -0,07F1 0,30 0,40 0,16 0,13 -0,03 0,17 0,41 0,19 0,05F2 0,06 0,06 -0,12 0,02 0,02 0,03 0,15 -0,18 0,38F1 -0,67 -1,02 0,10 -0,12 0,11 -0,09 -0,74 -0,95 -0,46F2 0,17 0,10 0,24 0,22 0,10 0,18 0,23 0,25 -0,34

NFDPM Nicotine CO NNK NNNF1 -0,13 -0,13 -0,08 -0,11 -0,10 -0,04 -0,22 -0,38 0,13F2 -0,12 -0,20 0,01 0,02 0,02 0,17 -0,07 -0,37 -0,48F3 0,06 0,22 -0,15 0,06 0,13 0,18 0,12 0,14 -0,60F1 0,50 0,43 0,60 0,50 0,51 0,51 0,33 -0,04 0,61F2 -0,01 -0,05 -0,04 0,08 0,08 0,25 0,00 0,01 -0,57

Equation 1

Acetaldehyde Acrolein Formaldehyde BaP

Group 1

Group 2

Group 3

Group 4

Equation 2Acetaldehyde Acrolein Formaldehyde BaP

Group 7

Group 5

Hoff. Compounds regressed on model 7 Components

Page 47: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Application to cigarette data

THEME - Bry, Redont, Verron; COMPSTAT 2010

How to assess prediction quality of Hoffmann Compounds?

. * ** ***

NFDPM Nicotine CO NNK NNNF1 0,03 -0,09 0,24 0,13 0,21 0,28 0,02 -0,40 -0,32F2 -0,22 -0,64 0,34 0,26 0,48 0,00 -0,53 -0,21 0,06F1 -0,19 -0,28 0,09 -0,06 -0,06 -0,10 -0,27 -0,47 -0,07F1 0,30 0,40 0,16 0,13 -0,03 0,17 0,41 0,19 0,05F2 0,06 0,06 -0,12 0,02 0,02 0,03 0,15 -0,18 0,38F1 -0,67 -1,02 0,10 -0,12 0,11 -0,09 -0,74 -0,95 -0,46F2 0,17 0,10 0,24 0,22 0,10 0,18 0,23 0,25 -0,34

NFDPM Nicotine CO NNK NNNF1 -0,13 -0,13 -0,08 -0,11 -0,10 -0,04 -0,22 -0,38 0,13F2 -0,12 -0,20 0,01 0,02 0,02 0,17 -0,07 -0,37 -0,48F3 0,06 0,22 -0,15 0,06 0,13 0,18 0,12 0,14 -0,60F1 0,50 0,43 0,60 0,50 0,51 0,51 0,33 -0,04 0,61F2 -0,01 -0,05 -0,04 0,08 0,08 0,25 0,00 0,01 -0,57

Equation 1

Acetaldehyde Acrolein Formaldehyde BaP

Group 1

Group 2

Group 3

Group 4

Equation 2Acetaldehyde Acrolein Formaldehyde BaP

Group 7

Group 5

. * ** ***

NFDPM Nicotine CO NNK NNNF1 0,03 -0,09 0,24 0,13 0,21 0,28 0,02 -0,40 -0,32F2 -0,22 -0,64 0,34 0,26 0,48 0,00 -0,53 -0,21 0,06

C_TO 0,99 0,25 -1,02 -37,51 -6,55 -1,60 1,71 6,58 1,14Mal_TO -0,63 -0,18 0,88 30,60 5,23 3,03 -1,14 -7,07 -7,91N_TO 0,19 0,13 -1,11 -33,58 -5,43 -8,17 0,51 12,52 28,28

PP_TO 0,92 0,16 -0,07 -9,60 -2,10 6,05 1,42 -4,67 -25,84MV_TO 0,00 0,00 0,00 0,14 0,02 0,00 -0,01 -0,02 0,01

2,50 0,84 -4,91 -162,08 -27,19 -24,08 4,80 45,33 74,36-0,25 -0,01 -0,34 -7,62 -1,04 -4,74 -0,32 5,68 18,09

NO3_TO -2,53 -0,53 1,31 58,58 10,86 -7,11 -4,13 -0,82 37,111,67 0,46 -2,15 -75,58 -13,00 -6,33 2,98 16,32 14,87

GFS_TO 0,05 0,00 0,09 2,14 0,31 1,10 0,05 -1,36 -4,13NH3_TO -4,76 -0,64 -1,70 -10,28 1,39 -49,24 -6,92 49,83 197,75NAB_TO -3,71 0,52 -12,94 -342,77 -51,81 -138,27 -3,06 181,82 510,65NAT_TO -0,29 -0,01 -0,38 -8,56 -1,17 -5,36 -0,37 6,42 20,47NNK_TO -2,83 -0,56 1,05 53,45 10,24 -11,55 -4,53 4,23 54,31NNN_TO -0,06 0,02 -0,32 -8,88 -1,37 -3,20 -0,02 4,33 11,66

F1 -0,19 -0,28 0,09 -0,06 -0,06 -0,10 -0,27 -0,47 -0,07-1,80 -0,22 0,48 -16,81 -1,59 -4,72 -1,84 -20,54 -10,52

PO4_PA 8,20 0,98 -2,18 76,34 7,22 21,43 8,34 93,27 47,77-2,09 -0,25 0,56 -19,45 -1,84 -5,46 -2,12 -23,76 -12,17

CaCO3_PA -0,38 -0,05 0,10 -3,58 -0,34 -1,00 -0,39 -4,37 -2,24PERM1_SOD -0,02 0,00 0,00 -0,16 -0,02 -0,04 -0,02 -0,19 -0,10

F1 0,30 0,40 0,16 0,13 -0,03 0,17 0,41 0,19 0,05F2 0,06 0,06 -0,12 0,02 0,02 0,03 0,15 -0,18 0,38

0,06 0,01 0,01 0,79 -0,01 0,18 0,07 0,11 0,654,00 0,41 -1,05 46,02 1,11 10,30 5,15 -14,62 170,04

PO4_TO -2,85 -0,42 -6,40 -47,85 5,96 -10,45 0,17 -73,63 383,50K_pc_TO 4,34 0,47 0,63 53,63 -0,46 11,93 4,63 4,98 59,30Hg_TO 0,21 0,02 0,09 2,69 -0,08 0,60 0,19 0,97 -1,60

0,80 0,09 0,49 10,71 -0,44 2,37 0,65 5,34 -15,581,43 0,16 0,26 17,83 -0,20 3,97 1,50 2,28 15,76

NO3_TO.1 2,70 0,31 1,00 34,67 -0,86 7,69 2,56 10,21 -5,76F1 -0,67 -1,02 0,10 -0,12 0,11 -0,09 -0,74 -0,95 -0,46F2 0,17 0,10 0,24 0,22 0,10 0,18 0,23 0,25 -0,34

FDENSC 0,16 0,02 0,00 1,34 -0,04 0,19 0,13 1,06 1,01HC_BIN -0,01 0,01 -0,09 -3,26 -0,20 -0,47 -0,03 -0,11 4,16PDEF -0,07 -0,01 0,01 -0,36 0,03 -0,05 -0,06 -0,48 -0,80

NFDPM Nicotine CO NNK NNNF1 -0,13 -0,13 -0,08 -0,11 -0,10 -0,04 -0,22 -0,38 0,13F2 -0,12 -0,20 0,01 0,02 0,02 0,17 -0,07 -0,37 -0,48F3 0,06 0,22 -0,15 0,06 0,13 0,18 0,12 0,14 -0,60

TAR 0,05 0,01 0,01 2,17 0,24 0,07 0,05 0,55 -0,77NICO 0,78 0,13 -0,47 32,32 4,77 2,55 0,79 8,61 -25,48CO 0,00 -0,01 0,12 0,87 -0,16 -0,24 0,00 0,02 2,37

0,00 0,00 0,00 0,03 0,00 0,00 0,00 0,01 0,040,00 0,00 0,02 0,32 -0,01 -0,03 0,00 0,04 0,320,00 0,00 0,00 0,46 0,05 0,05 0,01 0,02 -0,440,07 0,01 -0,03 3,70 0,50 0,32 0,08 0,73 -3,05

NNK_MS 0,01 0,00 0,00 0,05 0,00 -0,07 0,01 0,16 0,52NNN_MS 0,00 0,00 0,00 -0,07 -0,01 -0,03 0,00 0,04 0,24

Group 5

F1 0,50 0,43 0,60 0,50 0,51 0,51 0,33 -0,04 0,61F2 -0,01 -0,05 -0,04 0,08 0,08 0,25 0,00 0,01 -0,57FV -0,06 0,00 -0,07 -3,45 -0,36 -0,25 -0,03 0,02 -0,92PD 0,05 0,00 0,05 4,65 0,49 0,58 0,02 0,00 -1,45

PDFNE -0,09 -0,01 -0,11 -4,60 -0,48 -0,26 -0,04 0,03 -2,02

Equation 1

Acetaldehyde Acrolein Formaldehyde BaP

Group 1Asp_TOCit_TO

Alka_TO

Group 2

Cit_PA

Acet_PA

Group 3

Mg_Ca_pcCl_TO

Pb_TOCd_TO

Group 4

Equation 2Acetaldehyde Acrolein Formaldehyde BaP

Group 7 Acetal_MSAcro_MSFo_MS

BaP_MS

Coefficients of exogenous variables in Hoffmann compounds models (from model 7)

Hoff. Compounds regressed on model 7 Components

Page 48: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

Application to cigarette data

THEME - Bry, Redont, Verron; COMPSTAT 2010

Hoffmann compounds: 1) laboratory measure vs model 7 prediction; 2) Relative error / reproducibility limits

Page 49: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

Groups 1, 3, 4, 5, 6 → Very little change:

Group 2:

Model = 2 2 2 2 2 3 3

Important bundle structures are close to components

a = 1, … , 7

Group G-2

Axis 1

Axis

2

Cit_PA

PO4_PA

Acet_PA

CaCO3_PA

PERM1_SOD

a = 1

Group G-7

Axis 1

Axis

2

NFDPM.1NICO.1

CO.1

Acetal.1Acro.1

Fo.1

BaP.1

NNK.1

NNN.1

Group 7: a = 1

Multiple Costructure criterion: effect of exponent a

Application to cigarette data

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THEME - Bry, Redont, Verron; COMPSTAT 2010

Groups 1, 3, 4, 5, 6 → Very little change:

Group 2:

Model = 2 2 2 2 2 3 3

Important bundle structures are close to components

a = 1, … , 7

Group G-2

Axis 1

Axis

2

Cit_PA

PO4_PA

Acet_PA

CaCO3_PA

PERM1_SOD

Group G-2

Axis 1

Axis

2

Cit_PAPO4_PA

Acet_PA CaCO3_PA

PERM1_SOD

a = 1 a = 7

Group G-7

Axis 1

Axis

2

NFDPM.1NICO.1

CO.1

Acetal.1Acro.1

Fo.1

BaP.1

NNK.1

NNN.1

Group G-7

Axis 1

Axis

2NFDPM.1NICO.1

CO.1Acetal.1

Acro.1

Fo.1

BaP.1

NNK.1

NNN.1

Group 7: a = 1 a = 7

Multiple Costructure criterion: effect of exponent a

Application to cigarette data

towards variable selection

Page 51: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● From the explanatory point of view, THEME allowed to separate the complementary roles, on Hoffmann Compounds, of:➢ Tobacco quality (stalk position, pct of cutters and strips...)➢ Tobacco type (Burley, Flue Cured, Oriental, Virginia)➢ Combustion chemical enhancers or inhibitors related to tobacco or paper➢ Filter retention power.➢ Filter ventilation power

● From the predictive point of view, THEME gave out a complete and robust model having accuracy within reproducibility limits

When all predictors are mixed up, the filter ventilation effect masks the role of chemical constituents.

THEME confirmed the relevance of the chemists' conceptual model.

Application to cigarette dataConclusion

Page 52: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

● From the explanatory point of view, THEME allowed to separate the complementary roles, on Hoffmann Compounds, of:➢ Tobacco quality (stalk position, pct of cutters and strips...)➢ Tobacco type (Burley, Flue Cured, Oriental, Virginia)➢ Combustion chemical enhancers or inhibitors related to tobacco or paper➢ Filter retention power.➢ Filter ventilation power

● From the predictive point of view, THEME gave out a complete and robust model having accuracy within reproducibility limits

When all predictors are mixed up, the filter ventilation effect masks the role of chemical constituents.

THEME confirmed the relevance of the chemists' conceptual model.

SoftwareFree R-based User-friendly interfaceBeta THEME 1.0 available on (mail) demand

Application to cigarette dataConclusion

Page 53: Multidimensional Exploratory Analysis of a Structural ... · ⇒ Look for dimensions: reflecting their group's structure & interpretable with respect to their theme 2) Many (redundant)

THEME - Bry, Redont, Verron; COMPSTAT 2010

Thank you, all