Integrating a Complicated Function in MATLAB with Triplequad

[quin]

Dear users
I want to get a triple integral from "X,y,z" in MATLAB like this: triplequad(f,0,1,0,1,0,1) but because my "f" is very very complicated function of x,y,z , it can not do it, so I want to convert my integral to a summation and istead of my integral limits I want to make sum in a way that each of x,y,z vary from 0 to 1 by steps of 0.01
So would you mind tell me what should I write in matlab?

thanks

 

[jedishrfu]

http://www.mathworks.com/help/matlab/ref/triplequad.html

what is your function and what version of MATLAB are you using?

 

[quin]

thank you but my MATLAB is 2011
let me explain you that infact why I want to change my triplequad to sigma. (summation)
I have a 12*12 symbolic matrix in terms of x,y,z ,I must first find its eigenvalues and when I found 12 terms, I must do some aljebraic operations on them and mix them into one sentence and after that Integrate over that finall sentence in terms x y z
but the 12*12 matrix is so complicated and MATLAB couldn't find the 12 eigenvalues. so I want to put my matrix and all of aljabraic operations in 3 " "for" loops" and during loops I sum that final sentence instead of integrating
In this way the 12*12 matrix will be numeric and can find its eigenvalues but I won't have any x , y,z which I must integrate over them instead with those for loops I must the expression and cannot integrate.
I hope that yoU understand what I meant
thank you

 

[jedishrfu]

This really sounds like a project that you'll have to research and program yourself into matlab. I looked up MATLAB limits and it should be able to handle a 12x12 matrix.

http://www.mathworks.com/support/solutions/en/data/1-IHYHFZ/index.html

Perhaps if you break things up so the matrix isn't so complicated.

If this is a project we can only help with hints, we can't do the work for you.

By sentence I assume you mean equation, right?

Perhaps if you describe your problem in terms of discreet steps instead in paragraph form. Someone will be better able to help. What you've said so far is very generic and hard to figure out what you're trying to accomplish.

 

[alphy]

for your question. It sounds like you are trying to integrate a very complicated function using triplequad in MATLAB, but are having trouble due to the complexity of the function. In this case, it may be helpful to break down the integral into smaller parts and use a summation instead. This can be done by dividing the range of integration (0 to 1 in your case) into smaller intervals (0.01 in your example) and using a for loop to calculate the integral for each interval. You can then sum up the results from each interval to get an approximate value for the integral. The code for this approach would depend on the specific function you are integrating, but it would involve using a for loop and a sum function in MATLAB. I hope this helps!