Fast Convolution

Convolves two extremely large vectors in reasonable time.

Description

This function convolves two very large vectors very quickly. Enormous gains in speed are due to the use of two fft's and an ifft. To find out how to use this program, put it in you 'work' folder and type "help fconv".

• MATLAB release: MATLAB 5.3 (R11)

[Luigi Rosa]

Other methods should be considered (Overlap-add method, overlap-save method,...) which use the linearity of this operator.

[concerned citizen]

The output of this finction is normalized to +-1. In otherwords, >>output=output/max(abs(output));

[R Hu]

Matlab function 'conv' is implemented rather fast itself.

[anony mouse]

Matlab's conv function is nearly twice as fast as this one, at least in R2006a.

[anony mouse]

This is actually faster if both signals are very large. If only one is large then Matlab's function wins.

[chandra sekhar]

 

[Charles Jackson]

Fantastic. Sped up my code by a factor of 20.

Crashes if the output is all zero (because it tries to normalize the output to a maximum of 1). Very simple to fix this though.

[Ismail Al Anshori]

Very impressive!
This can make my convolution reverb of my final assignment perform faster and faster.
Thanks a lot.

[Mike Cohen]

500x improvement. nice work, thanks for sharing that. note that you need to comment out the normalization (last line of code) if the convolved values are meaningful.

[anjar si]

according to my results are not appropriate, because the large value generated is not the same compared with conv.m

[Drew Weymouth]

This is really great for implementing convolution reverb. Thanks!