Question: question regarding PDEtools[declare]

Hi all,

I have a function defined as a sum:

with(PDEtools): mfx:=(x,y,ufx)->sum(ufx[k]*(x-x[k])*(y-y[k]),k);

I want to declare mfx(x,y,ufx) so that it would appear as mfx in subsequent displays. However, when I tried

declare(mfx(x,y,ufx));

Maple tells me that "Error, (in PDEtools:-declare) cannot declare objects as sum(ufx[k]*(x-x[k])*(y-y[k]), k)".

How can I solve this problem?

Thanks.

Please Wait...