Re: Function matrix/vector assembly

[marco atzeri]

On 8/9/2012 6:48 AM, Grant Stephens wrote:
> Good Morning
>
> I am trying to assemble a function into a matrix or a vector but I have
> not found a way to do so except for typing it out manually, which is not
> possible as the it would be around 100 long and wide and changes after
> every timestep. The following represents what I am trying to do:
>
> f=@(x) [x^2 x 1]
> then I want to put a number of these into a vector so that the final
> vector would look like:
> vect=@(x) [x^2 x+x^2 1+x 1]
> Here I have added have done something like:
> vect=@(x) [f(x)(1) f(x)(2)+f(x)(1) f(x)(3)+f(x)(2) +f(x)(3)]
> So basically having a vector with f in 1 to 3 added to f in positions 2
> to 4. Obviously this would have to run in a loop as it is well over 100
> wide.

Not clear to have understood you need, something like this ?

octave:1> a=1:10
a =

    1    2    3    4    5    6    7    8    9   10

octave:2> a(1:end-1)
ans =

   1   2   3   4   5   6   7   8   9

octave:3> a(2:end)
ans =

    2    3    4    5    6    7    8    9   10

octave:4> a(1:end-1)+a(2:end)
ans =

    3    5    7    9   11   13   15   17   19


> Does anybody have any ideas? Am I missing something simple?
>
> Thank you.
Marco