Build nested sumsym expression

Hi all,

i'm tryng to write down this formula(cattura.png).

The point is the nested sum of series.

I actually have written this:

    x = symsum(1/(16^k)*symsum(symsum(symsum( obj.I(theta, k+level,y+(i/2^k),x+(j/2^k)), y,0,2), x,0,1), theta,1,3), k, 0, 3-level);

but i got an error on K...

[madhan ravi]

What’s 3-level?

[Marco Strambelli]

Sorry i forgot to mention some details:

level (in the image is "l"), "i", "j" are function's parameter.

"i","j" are indeces on matrix, "level" or "l" tells me which matrix I have to use (I have 3 different matrix).