From bug-request at octave dot org Wed Nov 23 10:47:35 2005
Subject: Re: weibull functions
From: Ben Barrowes <barrowes at alum dot mit dot edu>
To: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
Cc: Quentin Spencer <qspencer at ieee dot org>, bug@octave.org
Date: Wed, 23 Nov 2005 11:17:01 -0500

On Wednesday 23 November 2005 10:44 am, you wrote:
> On 23-Nov-2005, Quentin Spencer wrote:
> 
> | If I recall correctly, there are other functions like this that have 
> | been renamed for compatibility. When the new package system is in place, 
> | why not create backward compatible wrapper functions for all of them, 
> | take them out of the core octave distribution, and put them in a 
> | compatibility package?
> 
> Currently there are wrapper functions with the old names are in the
> "deprecated" directory.  Moving them to a separate package might be a
> reasonable thing to do, but it is a separate question from whether we
> should have
> 
>   weibull_*
>   weib*
>   wbl*
> 
> or skip the weib* names.  Did Matlab ever have those names, or was it
> a mistake in the last renaming?  If Matlab did have those names, did
> we get the argument order wrong in the last renaming, or has Matlab
> also switched the argument order in going from weib* to wbl*?
> 
> jwe
> 

ML did use those names but has changed with the advent of stat TB 4.1:
http://www.mathworks.com/access/helpdesk/help/toolbox/stats/rn/f2-54017.html

In addition, they changed their definitions in the weib*** functions, e.g.:
>> life = wblinv(0.5, 200, 6)          
life =
          188.148563055955
>> life = weibinv(0.5, 200, 6)
life =
         0.389014608848543
>> 

and

>> life = wblpdf(0.5, 200, 6) 
life =
             2.9296875e-15
>> life = weibpdf(0.5, 200, 6)
life =
          1.64763501087778
>> 


These changes, brought ML more in line with the rest of the stats community.


I am not sure how long the weib*** were being used in ML, but I think for a few years. We may
want to keep the wrapper for compatibility.

bb



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