5 replies to this topic

[Behnoud]

Why Cp doesn't calculate this (line 2):
[...] => u
Sum{u[1,i],i,1,5}

Note that u is a 5*5 matrix and sum means sigma.
I need this or my exam on saturday.
I use this command in main and eActivity.

[Gualberto Soto Sivila]

Why Cp doesn't calculate this (line 2):
[...] => u
Sum{u[1,i],i,1,5}

Note that u is a 5*5 matrix and sum means sigma.
I need this or my exam on saturday.
I use this command in main and eActivity.

This command Sum( ) is for list and not for matrix

Edited by Gualberto Soto Sivila, 15 January 2009 - 11:57 PM.

[Behnoud]

I use symbol Sigma from 2D tab, this is:
Sigma {u[1,i],i,1,5}.

[Kilburn]

Why don't you just use your brain and calculate it without using direct functions?

Anyway...

sum(matToList(trn(u),1))

Change 1 to whatever line you want to calculate. Remove "trn" if you want to get the sum of columns instead of lines.
Also, it's sum here, not sigma.

Edited by Kilburn, 16 January 2009 - 07:55 AM.

[Behnoud]

Why don't you just use your brain and calculate it without using direct functions?

Anyway...

sum(matToList(trn(u),1))

Change 1 to whatever line you want to calculate. Remove "trn" if you want to get the sum of columns instead of lines.
Also, it's sum here, not sigma.

Thanks for your comment.
I always use my brain.
using classpad and my brain, I did my exam in 1/3 of provided time.
I wrote more than 30 eactivity for my Advance Numerical analysis.
Btw, the problem was bigger than what I said. It was something like this:
Sigme(Sigma(u(i,j),i,1,10),j,1,10)
You know, I hate labour!

[vanhoa]

define library\mSum(m)=sum(matToList(m×fill(1,listToMat(matToList(trn(m),1))),1))

or

define library\mSum(m)=trn(m×fill(1,listToMat(matToList(trn(m),1))))×fill(1,listToMat(matToList(trn(trn(m)),1)))

Edited by vanhoa, 19 January 2009 - 02:50 AM.