%% 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.

%% 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(' ')

%% 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('  ')

%% 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('  ')