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Re: [Phys-L] Help! data analysis and display (graphing) apps.



My recommendation is that you try these programs, Bernard. Each will do nlls fits, including Excel (perhaps with add-ons), libreoffice (with any of various extensions like http://www.curvefitting.com/ ;), R will *certainly* do it (http://stat.ethz.ch/R-manual/R-patched/library/stats/html/nls.html), and my favorite, python, will handle your task with aplomb.

A quick and perhaps very non-dirty way of fitting your data would be to use Eureqa. It's more of an "equation discoverer" than fitter, but with restricting the form of your target functions, it does an admirable job of finding the parameter values. http://creativemachines.cornell.edu/eureqa

Finally, if you like Origin, a rather remarkable clone of it (though a bit slower) is Qtiplot: http://soft.proindependent.com/qtiplot.html ;. It runs natively for OS X, too. 
 
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________________________________
From: Bernard Cleyet <bernardcleyet@redshift.com>
To: Phys-L@Phys-L.org
Cc: Nancy Seese <nancyseese@redshift.com>
Sent: Sunday, September 2, 2012 11:29 PM
Subject: Re: [Phys-L] Help! data analysis and display (graphing) apps.


On 2012, Sep 02, , at 20:40, John Denker wrote:

On 09/02/2012 10:05 AM, Bernard Cleyet wrote:

I must input data multiple columns thousands of rows collected from,
for example, a photogate, then manipulate (average, find adjacent
differences, various algebraic functions, etc.) and display.

That's an important clarification of the request.

cut

Unfortunately, my "clarification" was grossly incomplete.  R would do it, except it appears designed for statisticians.  I need to fit to the data, for examples"  y=a*exp.(-b*x)* cos(c*t+d); y = a /(1+b*x), or y= a*(1-b*x), and more. 

What I want is essentially a spread sheet w/ NLLS fit (as many as 6? parameters) capable.  Origin would do except it isn't Apple platform.

I think I'll necessarily continue w/ Kaleidagraph, always saving the data before I execute any plots (that's when it crashes).


bc


p.s. Here's an example of what I've done w/ Kaleidagraph:


http://www.cleyet.org/Pendula,%20Horological%20and%20Otherwise/HSN/HSN%20published%20articles/PDFs/Q%20of%20a%20%22grand%20mother%22%20clock's%20pendulum.pdf
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