HOW DO I DO THAT IN MATLAB SERIES?
In this series, I am answering questions that students have asked me about MATLAB. Most of the questions relate to a mathematical procedure.
Contents
TOPIC
How do I integrate a continuous function?
SUMMARY
% Language : Matlab 2008a; % Authors : Autar Kaw; % Mfile available at % http://numericalmethods.eng.usf.edu/blog/integration.m; % Last Revised : March 28, 2009; % Abstract: This program shows you how to integrate a given function. clc clear all
INTRODUCTION
disp('ABSTRACT') disp(' This program shows you how to integrate') disp(' a given function') disp(' ') disp('AUTHOR') disp(' Autar K Kaw of http://autarkaw.wordpress.com') disp(' ') disp('MFILE SOURCE') disp(' http://numericalmethods.eng.usf.edu/blog/integration.m') disp(' ') disp('LAST REVISED') disp(' March 29, 2009') disp(' ')
ABSTRACT This program shows you how to integrate a given function AUTHOR Autar K Kaw of http://autarkaw.wordpress.com MFILE SOURCE http://numericalmethods.eng.usf.edu/blog/integration.m LAST REVISED March 29, 2009
INPUTS
% Integrate exp(x)*sin(3*x) from x=2.0 to 8.7 % Define x as a symbol syms x % Assigning the function to be differentiated y=exp(x)*sin(3*x); % Assigning the lower limit a=2.0; % Assigning the upper limit b=8.7;
DISPLAYING INPUTS
disp('INPUTS') func=[' The function is to be integrated is ' char(y)]; disp(func) fprintf(' Lower limit of integration, a= %g',a) fprintf('\n Upper limit of integration, b= %g',b) disp(' ') disp(' ')
INPUTS The function is to be integrated is exp(x)*sin(3*x) Lower limit of integration, a= 2 Upper limit of integration, b= 8.7
THE CODE
% Finding the integral using the int command % Argument 1 is the function to be integrated % Argument 2 is the variable with respect to which the % function is to be integrated - the dummy variable % Argument 3 is the lower limit of integration % Argument 4 is the upper imit of integration intvalue=int(y,x,a,b); intvalue=double(intvalue);
DISPLAYING OUTPUTS
disp('OUTPUTS') fprintf(' Value of integral is = %g',intvalue) disp(' ')
OUTPUTS Value of integral is = -525.527