[R] correlation, import of large tables, test for point-biserial c.c.?

[Spencer Graves]

Did you look at "?cor"?

The documentation observes that cor accepts an optional second argument. 
  The following works:
 > df1 <- data.frame(a=1:8, b=rep(c(-1, 1), 4),
+  c=rep(c(-1, 1), each=4))
 > cor(df1[,1], df1[, -1])
              b         c
[1,] 0.2182179 0.8728716
 >
hope this helps.  spencer graves

ArneSaatkamp at gmx.de wrote:
> Dear R help community,
> 
> I want to calculate correlations between environment parameters and species
> abundance data. When I use the cor() for my table (121 columns 91 rows) R
> generates a dataset with the correlations between all columns; 
> 
> 1) How can I limit the calculations to the correlations of only the first
> column with every other ? (Or:) How can I extract the line/row in question from
> the cor() dataset produced by R ?
> 
> 2) I assume that with one continuous factor and the other binary (0/1), 
> cor() gives the point-biserial correlation coefficient, but how can I find the
> method used by R ?
> 
> 3) I was not able to import (from "Excel") the whole 121x67 table, for
> instance I divided it into pieces. Is there a simple solution to import the whole
> file ?
> 
> 4) In the end I want to test the correlation coefficients. Where do I find
> an appropriated test for the point biserial correlation ? Can R calculate the
> coefficient and test it for all data in one step ?
> 
> I just started working & learning with R, but even after reading the R-help
> and Introduction to R, I still have big difficulties, so
> Thanks in advance for your help !!
> 
> Arne Saatkamp
> 
> Arne Saatkamp
> Inst. f. Biol. II - Abt. f. Geobotanik
> Schänzlestr. 1
> 79104 Freiburg
> Germany
>