Re: Using Mathematica for Electrophysiology Data Analysis
- To: mathgroup at smc.vnet.net
- Subject: [mg110434] Re: Using Mathematica for Electrophysiology Data Analysis
- From: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>
- Date: Fri, 18 Jun 2010 01:24:13 -0400 (EDT)
- References: <hva62h$qf2$1@smc.vnet.net>
Hi Fran=E7ois,
You could use something like
Reap[Histogram[RandomReal[NormalDistribution[0, 1], 200],
Automatic, (Sow[{#1, #2}]; #2) &]]
to get at binning and count data. Don't know about binning method, but
you could use one of the named binning methods instead of Automatic
used here if you want to be sure about the method used.
About NonLinearModelFit. If you don't say what you're doing it's hard
to say what you're doing wrong. One thing I can tell you:
NonLinearModelFit should be spelled with lowercase L. Perhaps that's
your problem?
Third question: see first question's answer. Counts are included.
Cheers -- Sjoerd
On Jun 16, 11:38 am, Fran=E7ois Blumenfeld <hypotypo... at me.com> wrote:
> Hi,
>
> I'm playing around with Mathematica to analyze some electrophysiology
> data; this is on my recreation time, so apologies if the following
> questions are very basic.
>
> I've imported data (pairs of time points and amplitudes) from pClamp
> into Mathematica as lists. The lists are pretty huge (around 150,000
> elements per list-I've separated times and amplitudes in two lists).
> I've created a histogram of the amplitudes list, letting Mathematica
> decide which binning method to use and the width of the bin. Without
> user input, it actually did a great job at picking bin width and
> binning method; but I don't know how to retrieve that information:
> i.e. what bin width was picked and what binning method used for a
> particular histogram?
>
> My second question is about fitting a multivariate Gaussian
> distribution to a multimodal (usually bimodal) histogram. I've payed
> around with NonLinearModelFit, but for some reason I don't think I'm
> doing it correctly. My third question is related to this: how do I
> retrieve the processed data from the histogram to construct a
> frequency table? I'm guessing that this might in fact be the
> intermediate step I need to complete before being able to fit a curve
> to the histogram data.
>
> Any suggestions welcome!
>
> Francois Blumenfeld-Kouchner