GSoC 2018: SymPy - Week 4
Another week of Coding Period has concluded.
Starting this week, I worked on PR #14765 for implementing Fast Walsh Hadamard Transform (
As pointed out by Kalevi, symbolic coefficients could be supported by this transform as the general Kronecker matrix only contains
+/-1, which means it essentialy requires only addition or subtraction to perform the transformation. Also, the PR review helped fix a minor issue related to string concatenation.
fwht looks like:
>>> from sympy import fwht, ifwht, symbols >>> fwht([4, 2, 2, 0, 0, 2, -2, 0]) [8, 0, 8, 0, 8, 8, 0, 0] >>> ifwht(_) [4, 2, 2, 0, 0, 2, -2, 0] >>> a, b, c, d = symbols('a b c d') >>> fwht([a, b, c, d]) [a + b + c + d, a - b + c - d, a + b - c - d, a - b - c + d] >>> ifwht(_) [a, b, c, d]
Documentation, doctests, and unit tests are also added for this transform.
Looking forward to next week, where I will be implementing XOR convolution using