computing issue

we have this formula p(x)=(<f,f_0>/<p_0,p_0>)*p_0 + (<f,f_1>/<p_1,p_1>)*p_1 + ... + (<f,f_n>/<p_n,p_n>)*p_n where (<f,f_0>) for example is calculated by this formula : Integral from -1 to 1 ( |f*f_0|dx )^1/2 . I know everything, f,f_n,p_n, everything. I am new to matlab and i cannt make it work :/ Any help would be much appreciated !!! Thanks in advance !!

[Daniel Shub]

What have you tried so far? Have you read any of the MATLAB documentation?

Answer 1

[Richard Brown]

You need to decide how to represent the f_i and f - whether by functions or by vectors (the function evaluated on some mesh).

Then you need to figure out how to evaluate the inner products. In the first case it would be a quadrature (lookup quad), and in the second, a (appropriately scaled) dot product. Hopefully that gives you enough to get going!

Or Google chebfun for the best of both worlds.