Add the values in an array

[gbuell]

I have a 2x9 array and I want to have Mathcad 14 sum up all the elements. I've gone through the different types of summations in Mathcad and I haven't gotten any of them to work. I did manage to get what I want by turning each column of the matrix into a vector using the column command (M<> in the matrix toolbar) and then adding up each vector sum(ctrl-4). But it seems like this method shouldn't be necessary.

 

[excognito]

Yes. The vector sum operator should really operate over a matrix as well as a vector.

The attached worksheet gives a few other ways it could be done ...

 

[gbuell]

That's great, I didn't know about the vec function, that's exactly what I wanted.

 

[excognito]

Please note that the vec function is not built-in; I wrote it because I several needs for it. It is defined within the Vector Support Function area (or, at least that's where I normally define it!).

 

[GregLocock]

a simple and obvious solution that seems to work is sigma over i sigma over j M sub i,j

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.