I needed a fast Kronecker product for sparse matrices recently, so here's the updated code. Feel free to use ...
Source: MathNet.Numerics.Extensions-src.zip
Benchmark (old vs. new):
Source: MathNet.Numerics.Extensions-src.zip
Benchmark (old vs. new):
Kronecker ( 5x 5) X (2410x2410) 5362ms 9ms OK
Kronecker ( 5x10) X (2410x2410) 5218ms 9ms OK
Kronecker (10x 5) X (2410x2410) 7279ms 9ms OK