# Computing 3-term Connection Coefficients for Wavelets

I am trying to calculate the three-term connection coefficients

$$Λ_{l,m}^{d_1,d_2,d_3} = ∫_{-∞}^∞ φ^{(d_1)}(x) φ^{(d_2)}_l(x) φ^{(d_3)}_m(x) dx$$

for Daubechies wavelets numerically using Python. This report (p. 20) gives a nice overview of how to calculate them.

I wrote a (well documented) implementation in python and for the two-term connection coefficients had no problems but when I compare my 3-term results with the ones of Resnikoff and Wells (1998) I find lots of errors (only the (l=m) coefficients appear to be correct).

I am starring at the code for weeks now, but I cannot find any errors. I would be very pleased if somebody would give me a hint where the error might be.

• you will probably be better off asking at either StackOverflow or SciComp.stackexchange.com – Willie Wong Jul 13 '16 at 17:32
• I guess StackOverflow is really the wrong place, but I did not know about SciComp! I will give it a try. Thanks! – J. Doe Jul 13 '16 at 19:21