Please add Weibull probability distribution function to non-linear curve fitting library

[Alex Valavanis]

Binary package hint: grace

In bug #535459, Nicola Ferralis added a very useful library of common peak functions to the non-linear curve fitting tool. It would be useful for my work if the Weibull probability distribution function (and its associated cumulative distribution function) could be added.

Details of the function are available at: http://en.wikipedia.org/wiki/Weibull_distribution

I may get round to doing this myself at some point, but it would be great if anyone else is feeling motivated!

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: grace 1:5.1.22-7
ProcVersionSignature: Ubuntu 2.6.35-9.14-generic 2.6.35-rc5
Uname: Linux 2.6.35-9-generic i686
Architecture: i386
Date: Thu Jul 22 16:02:49 2010
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, user)
 LANG=en_GB.utf8
 SHELL=/bin/bash
SourcePackage: grace

[Nicola Ferralis (feranick)]

I can easily add it. I'll try to have it done in the next couple of days.

Nicola

[Nicola Ferralis (feranick)]

Attached two patches for this bug. The first (nonlinear_extended_2.diff) overwrites the original patch for bug #535459, while the second can be applied on top of that.

I'll prepare test builds later today.

[Nicola Ferralis (feranick)]

BTW, I only added the probability density function:

F(x; A0, A1) = (A0/A1)*((x/A1)^(A0-1))*exp(-(x/A1)^A0)

I am not sure you need more: if so it would be great if you could be more specific.

Nicola

[Nicola Ferralis (feranick)]

Test builds available here:

https://launchpad.net/~grace-extended/+archive/ppa/+packages

[Alex Valavanis (valavanisalex)]

Hi Nicola, thanks very much for the time you have spent on this. The cumulative distribution function may be useful too, if you have time:

y = 1 - exp(-(x/lambda)^k)

[Nicola Ferralis (feranick)]

I uploaded the new patches with both the cumulative and probability density distributions. Test builds are available soon in the grace-extended ppa.

I also submitted the patches in the debian bug report (where they will most likely be applied).

Please let me know if more function are needed.

[Alex Valavanis (valavanisalex)]

Hi Nicola,

Thanks very much for your help with this. I'm glad to see this has made it into the Debian package. Let's hope that your function library will eventually appear in the next upstream release.

[Nicola Ferralis (feranick)]

No problem, my pleasure.

Yes, getting it upstream would be nice. It's a good consolation that at least Nicholas is doing a terrific job in maintaining the Debian package.

[Nicola Ferralis (feranick)]

By the way, backports of version 5.1.22-8 are available for lucid here:

https://launchpad.net/~lucid-bleed/+archive/ppa

[Alex Valavanis (valavanisalex)]

This bug was fixed in the package grace - 1:5.1.22-8

---------------
grace (1:5.1.22-8) unstable; urgency=low

  * control: Increment Standards-Version to 3.9.1, no changes necessary.
  * patches/nonlinear_extended.diff: Revision by Nicola Ferralis to add
    Weibull probability distribution fitting. (Closes: #589965)
 -- Alex Valavanis <email address hidden> Tue, 27 Jul 2010 11:02:37 -0700