[R] S: appropriate significance tests

[soeren.vogel at eawag.ch]

Hello

(1) How can I compare two Pearson correlation coefficients for significant differences without the use of the raw data?

(2) How can I compare two linear regression coefficients for significant differences without the use of the raw data?

(3) How can I compare two multiple correlation coefficients (as produced in a linear regression) for significant differences, again, if the raw data should not be used?

<src type="perhaps useful">
da <- data.frame(
  "y1"=sample(1:5, 40, repl=T),
  "y2"=sample(1:5, 40, repl=T),
  "x1"=sample(1:5, 40, repl=T),
  "x2"=sample(1:5, 40, repl=T)
)
cro1 <- cor(da$y1, da$x1)
cro2 <- cor(da$y2, da$x1)
lmo1 <- lm(y1 ~ x1 + x2, data=da)
lmo2 <- lm(y2 ~ x1 + x2, data=da)
</src>

Thanks, Sören