Re: Dealing with large data sets
- To: mathgroup at smc.vnet.net
- Subject: [mg42996] Re: Dealing with large data sets
- From: Bill Rowe <listuser at earthlink.net>
- Date: Thu, 7 Aug 2003 00:53:59 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On 8/6/03 at 3:16 AM, civnrn at hotmail.com (Rees) wrote:
> I have a large dataset (156381 points) and I wish to fit a
> distribution to the dataset. However I cannot seem to get Mathematica to
> recognise the dataset. I imported the data as "testdata" then did
> Mean[testdata]. Unfortunately this command just repeated the data and
> failed to give me the mean value.
> I repeated everything using another data format:
> {0.217,0.434,0.652 etc...} with the same response.
Although you didn't state what version of Mathematica you are using, from your description I assume it is a version before 5.0. In these versions it is necessary to either load the package Statistics`DescriptiveStatistics` or to write a function definition defining the function Mean. That is, there is no built in function Mean in versions before version 5.0
You can load the package by doing
<<Statistics`DescriptiveStatistics`
or
<<Statistics`
A simple piece of code for computing the mean is:
mean[x_]:= Tr[x]/Length[x]