Evaluate the following triple integral using single applications of Simpson’s 1/3 rule.

Evaluate the following triple integral using single applications of Simpson’s 1/3 rule. I have all the code for this question but I am getting error: Undefined function or variable 'simpson'. How to fix this error or add the 'simpson' function.

x1 = [-3:0.01:1];

fx1 = (x1).^2;

a= simpson(x1,fx1 , [],'1/3');

y1 = [0:0.01:2];

fy1 = ones(length(y1),1);

b= simpson(y1,fy1 , [],'1/3');

z1 = [-2:0.01:2];

fz1 = ones(length(z1),1);

c= simpson(z1,fz1 , [],'1/3');

I1 =a*b*c;

x2 = [-3:0.01:1];

fx2 = ones(length(x2),1);

aa= simpson(x2,fx2 , [],'1/3');

y2= [0:0.01:2];

fy2 = y2;

bb= simpson(y2,fy2 , [],'1/3');

z2 = [-2:0.01:2];

fz2 = z2;

cc= simpson(z2,fz2 , [],'1/3');

I2=aa*bb*cc;

Answer 1

[KSSV]

There is no inbuilt function named simpson in matlab. You may check quad inbuilt function or download the file from the exchange.

https://in.mathworks.com/matlabcentral/fileexchange/25754-simpson-s-rule-for-numerical-integration

[Moon Shadow]

What about simps function? I also get: Undefined function or variable 'simps'.

[Moon Shadow]

Here Simpson function https://www.mathworks.com/matlabcentral/fileexchange/28726-simpson-s-rule-integration/content/simpsons.m

Answer 2

[Moon Shadow]

 How to use file from the exchange in the matlab? I want to use simps function.

[KSSV]

Download the file, copy in a folder, read the documentation part of the file, see how to input and then use. Mostly they give an example on how to run. First run the code for example case.