Re: Re: Re: Mathematica function to calculate correlation coefficient?
- To: mathgroup at smc.vnet.net
- Subject: [mg108185] Re: [mg108131] Re: [mg108094] Re: Mathematica function to calculate correlation coefficient?
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Wed, 10 Mar 2010 01:43:52 -0500 (EST)
- References: <hmvq80$17c$1@smc.vnet.net> <201003081113.GAA03974@smc.vnet.net>
- Reply-to: drmajorbob at yahoo.com
If n is a InterpolationFunction returned by NDSolve or a symbolic function
returned by Solve, n[t] is obviously not a list of 8 values; it's one
value for each t.
You can create such a list, of course, with, for instance, Array[n,8] or
n/@{.1,.3,.4,.8,.9,1.2,...} (any list of eight t values).
Once you have a pair of same-length lists, Correlation will calculate what
the name says.
Bobby
On Tue, 09 Mar 2010 05:20:19 -0600, Yun Zhao <yun.m.zhao at gmail.com> wrote:
> Thanks for your reply. But remember, the set of data values is 20 data
> points, and my computed distribution of n(t) is a function of t, so
> thousands and thousands of points. When I tried to use
>
> Correlation[data1, n(t)]
>
> I get the error "Correlation::vctmat: The arguments to Correlation are
> not a
> pair of vectors or a pair of matrices of equal length." Please tell me
> what
> I did wrong. Thank you.
>
> Correlation::vctmat: "
>
> StyleBox[\"\"\", \"MT\"] The arguments to Correlation are not a pair of
> vectors or a pair of matrices of equal length
>
>
> On Mon, Mar 8, 2010 at 5:13 AM, Sjoerd C. de Vries <
> sjoerd.c.devries at gmail.com> wrote:
>
>> Surprisingly, you can use the function Correlation to calculate the
>> correlation between two lists. In your case you should probably use
>> the set of predicted values and the sat of actual data values.
>>
>> Cheers -- Sjoerd
>>
>> On Mar 7, 11:05 am, Yun Zhao <yun.m.z... at gmail.com> wrote:
>> > Hi everyone,
>> >
>> > I solved a differential equation, and got a solution n(t). Now I
>> have
>> > collected 8 data points at 8 different times. I plotted the solution
>> of
>> > n(t), and the curve intersect the 8 data points quite well on a graph
>> of
>> > n(t) vs. t. How do I use Mathematica 7.0 to calculate the correlation
>> > coefficient R^2 value of how well the n(t) solution fit the data
>> points?
>> > Thank you very much.
>>
>>
>>
>
>
--
DrMajorBob at yahoo.com
- References:
- Re: Mathematica function to calculate correlation coefficient?
- From: "Sjoerd C. de Vries" <sjoerd.c.devries@gmail.com>
- Re: Mathematica function to calculate correlation coefficient?