R help - Aug 2004 - Question on Differentiating Two Populations in R

Hello All,

Forgive me if this a blatantly newbie question or not germane to the 
list, but i was wondering if my current approach to my problem is the 
best way in R.

I have two experimental datasets (positive and negative) of differing 
lengths and a large number of ways of numerically expressing the data 
by using various scales to represent each data point.

I am looking for a scale that will allow me to differentiate between 
the positive and negative populations.

Each dataset is simply a list of numbers: 43 numbers in the positive 
case and 9 in the negative (small sets, i know, but it's all the data i 
currently have) and I have hundreds of scales.

I assign each dataset to a variable using scan() (each are in separate 
files).

My initial comparison of the two datasets is simply a boxplot with the 
hope that the two do not overlap too much...

Is this the way you would approach this problem? Is there an easier way 
of doing this in R?

Any and all help is greatly appreciated!

james

Sounds like you need a course in statistics.  This is a 2-sample
comparison problem.  It might be worth finding a local stat
consultant, it shouldn't take much time.


"James R. Graham" <jamesrgraham at mac.com> writes:
> Hello All,
>
> Forgive me if this a blatantly newbie question or not germane to the
> list, but i was wondering if my current approach to my problem is the
> best way in R.
>
> I have two experimental datasets (positive and negative) of differing
> lengths and a large number of ways of numerically expressing the data
> by using various scales to represent each data point.
>
> I am looking for a scale that will allow me to differentiate between
> the positive and negative populations.
>
> Each dataset is simply a list of numbers: 43 numbers in the positive
> case and 9 in the negative (small sets, i know, but it's all the data
> i currently have) and I have hundreds of scales.
>
> I assign each dataset to a variable using scan() (each are in separate
> files).
>
> My initial comparison of the two datasets is simply a boxplot with the
> hope that the two do not overlap too much...
>
> Is this the way you would approach this problem? Is there an easier
> way of doing this in R?
>
> Any and all help is greatly appreciated!
>
> james
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
>
-- 
Anthony Rossini			    Research Associate Professor
rossini at u.washington.edu            http://www.analytics.washington.edu/ 
Biomedical and Health Informatics   University of Washington
Biostatistics, SCHARP/HVTN          Fred Hutchinson Cancer Research Center
UW (Tu/Th/F): 206-616-7630 FAX=206-543-3461 | Voicemail is unreliable
FHCRC  (M/W): 206-667-7025 FAX=206-667-4812 | use Email

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If I am understanding correctly you can have a look at
 ? t.test
and ? wilcox.test
depending on assumptions.

Jim

----- Original Message -----
From: "James R. Graham" <jamesrgraham at mac.com>
To: <r-help at stat.math.ethz.ch>
Sent: Saturday, August 07, 2004 9:38 PM
Subject: [R] Question on Differentiating Two Populations in R

> Hello All,
>
> Forgive me if this a blatantly newbie question or not germane to the
> list, but i was wondering if my current approach to my problem is the
> best way in R.
>
> I have two experimental datasets (positive and negative) of differing
> lengths and a large number of ways of numerically expressing the data
> by using various scales to represent each data point.
>
> I am looking for a scale that will allow me to differentiate between
> the positive and negative populations.
>
> Each dataset is simply a list of numbers: 43 numbers in the positive
> case and 9 in the negative (small sets, i know, but it's all the data i
> currently have) and I have hundreds of scales.
>
> I assign each dataset to a variable using scan() (each are in separate
> files).
>
> My initial comparison of the two datasets is simply a boxplot with the
> hope that the two do not overlap too much...
>
> Is this the way you would approach this problem? Is there an easier way
> of doing this in R?
>
> Any and all help is greatly appreciated!
>
> james
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html