introduction to matlab. outline 2 introduction matlab environment getting help vectors,...

Introduction to MATLAB

Multimedia Systems ([email protected])

Outline*IntroductionMATLAB EnvironmentGetting HelpVectors, Matrices, and Linear AlgebraPlottingUser Defined FunctionsImage Manipulation and ProcessingAudio ProcessingFilters and OperationsMultimedia Systems ([email protected])


IntroductionMATLAB Stands for MATrix LABoratory.The MATLAB environment allows the user to:manage variablesimport and export dataperform calculationsgenerate plotsdevelop and manage files for use with MATLAB.A script can be made with a list of MATLAB commands like other programming language.

Multimedia Systems ([email protected])*


EnvironmentMultimedia Systems ([email protected])*


Getting HelpType one of following commands in the command window:help lists all the help topichelp topic provides help for the specified topichelp command provides help for the specified commandhelp help provides information on use of the help commandhelpwin opens a separate help window for navigationlookfor keyword Search all M-files for keywordOr simply press F1 and use the graphical help window.



VariablesVariable names:Must start with a letterMay contain only letters, digits, and the underscore _Matlab is case sensitive, i.e. one & OnE are different variables.Matlab only recognizes the first 31 characters in a variable name.when a semi-colon>> tutorial = 1234;>> tutorial = 1234; is placed at the end of each command, the result is not displayed.



Variables (Contd)Special variables:ans : default variable name for the result pi: = 3.1415926eps: = 2.2204e-016, smallest amount by which 2 numbers can differ.Inf or inf : , infinityNaN or nan: not-a-numberCommands involving variables:who: lists the names of defined variableswhos: lists the names and sizes of defined variablesclear: clears all variables, reset the default values of special variables.clear name: clears the variable nameclc: clears the command windowclf: clears the current figure and the graph window.



Vectors>> x = [ 0 0.25*pi 0.5*pi 0.75*pi pi ]x =0 0.7854 1.5708 2.3562 3.1416>> y = [ 0; 0 25*pi; 0 5*pi; 0 75*pi; ]y =00.78541.5708 y2.35623.1416



Vectors (Contd)Vector Addressing A vector element is addressed in MATLAB with an integer index enclosed in parentheses.>> x(3)The colon notation may be used to address a block of elements (start : increment : end)start is the starting index, increment is the amount to add to each successive index, and end is the ending index. A shortened format (start : end) may be used if increment is 1.>> x(1:3)ans =0 0.7854 1.5708NOTE: MATLAB index starts at 1.



Vectors (Contd)Multimedia Systems ([email protected])*


Array OperationsScalar-Array Mathematics:

Element-by-Element Array-Array Mathematics:



MatricesA Matrix array is two-dimensional, having both multiple rows and multiple columns, similar to vector arrays:It begins with [, and end with ]spaces or commas are used to separate elements in a rowsemicolon or enter is used to separate rows.Matrix Addressing:matrixname(row, column)colon may be used in place of a row or column reference to select the entire row or column.



Matrices (Contd)Multimedia Systems ([email protected])*


Example, Linear EquationsMultimedia Systems ([email protected])*

Multimedia Systems ([email protected].ir)

PlottingPlotting Curves:plot (x,y) generates a linear plot of the values of x (horizontal axis) and y (vertical axis).semilogx (x,y) generate a plot of the values of x and y using a logarithmic scale for x and a linear scale for ysemilogy (x,y) generate a plot of the values of x and y using a linear scale for x and a logarithmic scale for y.loglog(x,y) generate a plot of the values of x and y using logarithmic scales for both x and yMultiple Curves:plot (x, y, w, z) multiple curves can be plotted on the same graph by using multiple arguments in a plot command. The variables x, y, w, and z are vectors. Two curves will be plotted: y vs. x, and z vs. w.legend (string1, string2,) used to distinguish between plots on the same graphMultiple Figures:figure (n) used in creation of multiple plot windows. place this command before the plot() command, and the corresponding figure will be labeled as Figure nclose closes the figure n window.close all closes all the figure windows.Subplots:subplot (m, n, p) m by n grid of windows, with p specifying the current plot as the pth window



Plotting (Contd)Multimedia Systems ([email protected])*


Flow ControlMultimedia Systems ([email protected])*


Loops

break is used to terminate the execution of the loop.



M-FilesA M-file is a group of MATLAB commands.MATLAB can open and execute the commands exactly as if they were entered at the MATLAB command window.To run the M-files, just type the file name in the command window. (make sure the current working directory is set correctly)



User Defined FunctionsAdd the following command in the beginning of your m-file:function [output variables] = function_name (input variables);Note that the file name should be the same as the function name.Multimedia Systems ([email protected])*


Images in MATLABMATLAB can import/export several image formatsBMP (Microsoft Windows Bitmap)GIF (Graphics Interchange Files)HDF (Hierarchical Data Format)JPEG (Joint Photographic Experts Group)PCX (Paintbrush)PNG (Portable Network Graphics)TIFF (Tagged Image File Format)XWD (X Window Dump)MATLAB can also load raw-data or other types of image data

Data types in MATLABDouble (64-bit double-precision floating point)Single (32-bit single-precision floating point)Int32 (32-bit signed integer)Int16 (16-bit signed integer)Int8 (8-bit signed integer)Uint32 (32-bit unsigned integer)Uint16 (16-bit unsigned integer)Uint8 (8-bit unsigned integer)

*Multimedia Systems ([email protected])


Images in MATLAB Binary images : {0,1} Intensity images : [0,1] or uint8, double etc. RGB images : m-by-n-by-3 Indexed images : m-by-3 color map Multidimensional images m-by-n-by-p (p is the number of layers)*Multimedia Systems ([email protected])


Image import and exportRead and write images in Matlab>> I=imread('cells.jpg');>> imshow(I)>> size(I)ans = 479 600 3 (RGB image)>> Igrey=rgb2gray(I);>> imshow(Igrey)>> imwrite(lgrey, 'cell_gray.tif', 'tiff')Alternatives to imshow>>imagesc(I)>>imtool(I)>>image(I)*Multimedia Systems ([email protected])


Images and MatricesHow to build a matrix (or image)?>> A = [ 1 2 3; 4 5 6; 7 8 9 ]; A = 1 2 3 4 5 67 8 9>> B = zeros(3,3) B = 0 0 00 0 00 0 0>> C = ones(3,3) C =1 1 11 1 11 1 1

>>imshow(A) (imshow(A,[]) to get automatic pixel range)*Multimedia Systems ([email protected])


Image format conversionConvert between intensity/indexed/RGB to binary format:dither()Convert between intensity format to indexed format:gray2ind()Convert between indexed format to intensity format:ind2gray()Convert between indexed format to RGB format:ind2rgb()Convert a regular matrix to intensity format by scaling: mat2gray()Convert between RGB format to intensity format: rgb2gray()Convert between RGB format to indexed format:rgb2ind()Multimedia Systems ([email protected])*


ColormapsI = imread (lena.bmp);imshow (I);colormap (cool);

Autumn, bone, colorcube, cool, copper, flag, gray, hot, hsv, jet, pink, prism, spring, summer, white, winterMultimedia Systems ([email protected])*


Videomov = aviread(filename)mov = aviread(filename, index)

fileinfo = aviinfo(filename)



Digital AudioMultimedia Systems ([email protected])*


Audio[road,fs]=wavread('road.wav'); The array road now contains the stereo sound data and fs is the sampling frequency.This data is sampled at the same rate as that on a music CD (fs=44,100 samples/second).

The left and right channel signals are the two columns of the road array:left=road(:,1);right=road(:,2);



time=(1/44100)*length(left);t=linspace(0,time,length(left));plot(t,left)xlabel('time (sec)');ylabel('relative signal strength')

soundsc(left,fs) % plays left channel as monosoundsc(right,fs) % plays right channel mono (sound nearly the same)soundsc(road,fs) % plays stereo (ahhh)





*

introduction to matlab. outline 2 introduction matlab environment getting help vectors,...

Documents

Use of Matlab for Analysis and Plotting of Accoustic Well Data

MATLAB Week 3 17 November 2009. Outline Graphics – Basic plotting – Editing plots from GUI – Editing plots from m-file – Advanced plotting commands

Scientific Plotting with Matplotlib - SERSOLsersol.weebly.com/uploads/9/8/8/1/98818956/matplotlib_handout.pdf · Therefore, the majority of plotting commands in pylab has Matlab(TM)

Plotting - Loyola University Marylandmath.loyola.edu/~chidyagp/sp19/plotting.pdf · Plotting in MATLAB 2D Plots Plotting Scalar functions Plot f(x) = x2 on [ 2ˇ;2ˇ]. 1 De ne a discrete

1 Introduction to MATLAB MATLAB is all of the following: 1.Computational environment 2.Plotting software 3.Programming language Typical applications: 1.Calculations

Matlab - An Introduction to Matlab

3D Graphics in MATLAB - UPC Universitat Politècnica de ... · 3D Graphics in MATLAB We'll introduce different types of plotting in 3D. MATLAB has different plotting approaches for

DSP Lab Manual - ece.rutgers.eduorfanidi/ece348/labs-2013.pdf · 0.3. Using MATLAB The plotting of data created by C or MATLAB programs can be done using MATLAB’s extensive plotting

MATLAB - Carleton Universityrhfischl/MATLAB/... · MATLAB makes the plotting of vectors and matrices of values against vectors of domain or index values particularly simple. This

GRAFLAB 2.3 for UNIX A MATLAB Database, Plotting, and User’s …/67531/metadc692879/... · A MATLAB Database, Plotting, and Analysis Tool User's Guide William N. Dunn Mechanical

Plotting and Model Building in MATLAB

Introduction to MATLAB for Engineers, Third Edition Chapter 5 Advanced Plotting PowerPoint to accompany Copyright © 2010. The McGraw-Hill Companies, Inc

Practical Training: Plotting Model outputs using Matlab :

MATLAB for the Sciences - LaGrange Collegehome.lagrange.edu/.../MATLAB-Week1-Lecture5.pdf · MATLAB for the Sciences Plotting, Simple Arrays, and Special Functions Jon M. Ernstberger

MATLAB Introduction - University Of Illinois · Matlab Interface ... Base cost: $49, Suite: $99 (https: ... breakpoints, differentiation, integrals, functions, plotting, for

DATA PLOTTING WITH MATLAB - unibs.it · 1. WHY MATLAB? WHY MATLAB? Matlab is a high-level programming language that provides a numerical computing environment for algorithms development,

An introduction to Plotting in MATLAB Rikard Johansson Department of Biomedical Engineering (IMT) Linköping University rikard.johansson@liu.se 2015-03-19

Development of Matlab-based data plotting and analysis for ... · Shot Analysis Module • Matlab-based data plotting and analysis for high power ICRH system. • GUIDE generates

Plotting Pada Matlab

MATLAB Basics 6 plotting - University of Sheffieldcontroleducation.group.shef.ac.uk/MATLAB/MATLAB... · MATLAB Basics 6 plotting Anthony Rossiter ... (2,-1,'Text in the graph') x1,y1

Chapter 11 Plotting Chapter 13 Imageserives/289_F12/Chapter_11_13_Erives.pdf · 11.1 Plotting in General • Plotting is perhaps the most powerful aspect of MATLAB. Plots can be two-or

PLOTTING PHASE PORTRAITS WITH MATLAB:

graphs plotting in MATLAB

Plotting With Matlab

Matlab - stat.purdue.edufigueroa/Teaching/Stat541/IntroMatlab... · Matlab A numerical computing environment and fourth-generation programming language. Matrix manipulations, Plotting

Beyond the Mouse - grapenthin · Beyond the Mouse MATLAB Input & Output (Getting data into MATLAB and plotting it)

Introduction to Matlab 1. Outline: What is Matlab? Matlab Screen Variables, array, matrix, indexing Operators Plotting Flow Control Using of M-File Writing

Chapter 5 Review: Plotting Introduction to MATLAB 7 Engineering 161

3D Graphics in MATLAB · 2021. 4. 6. · 3D Graphics in MATLAB We'll introduce different types of plotting in 3D. MATLAB has different plotting approaches for showing data in 3D:

Matlab plotting

MATLAB Tutorial – CCN Course 2012 - ccnss.org · Introduction Arrays Coding Plotting Network model: Step 1 Step 2 Step 3 Step 4 Exercises MATLAB Tutorial – CCN Course 2012 How

3D Graphics in MATLAB - ČVUT, FJFI, Katedra fyzikální ...kfe.fjfi.cvut.cz/~sinor/tmp/edu/pin3/docs/matlab/3dplot.pdf3D Graphics in MATLAB We'll introduce different types of plotting

MATLAB 7 Getting Started Guidetdlinh/ThuchanhTH/Matlab_getstart.pdf · Overview of Plotting.....3-2 Plotting Process.....3-2 Graph Components .....3-6 Figure Tools ... MATLAB has

Introduction to Matlab. I use Matlab for: Data analysis Data plotting Image Analysis Also – Simulations (solving odes/pdes/finite element methods) – Minimisations,

MATLAB Week 4 01 December 2009. Outline More plotting – A few other 3-D plotting functions – Basic volume visualization Creating functions Vectorized