Updates

There will hopefully be new programs and updated versions of old programs. If you are interested in being notified about updates/additions, send your email address to jwfox1@swbell.net. Bug reports and questions about the programs should be directed to the same address. Everything received will be read. If the number of questions is not large, they will be answered.

Almost all the code has been written by this Jim Fox. Therefore, there are likely to be bugs. Please report them to the above email address.

There are also limitations. For example, lroots and broots can factor the following polynomial,

>> x=unfactor([1e-50, 1, 1e50],1);
>> z=lroots(x)
z =
1.000000000000000e+000
9.999999999999999e-051
1.000000000000000e+050

However, the FFT can not handle this large a dynamic range - ifft(fft(x)) underflows. This causes all 3 phase unwrappers to fail because they assume fft(x) is accurate, and they use it to correct the phase unwrapping. Unwrapz actually computes the phase correctly but then destroys it when it tries to adjust it to match angle(fft(x)) modulo pi.