anyone want to tell me how to map coords from [-1,1] to [0,1]? much appreciated
Actually there are infinitely many mappings from [-1,+1] to [0,1], but I assume you mean the affine transformation T specified by T(-1)=0 and T(+1)=1.
In general you can do an affine mapping T: x->x’ specified by T(a)=p and T(b)=q like this:
x'=p+(x-a)*(q-p)/(b-a)
or in your specific case:
x'=(x+1)/2