[R] Odp: Regression and data types

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 26.09.2008 14:17:59:

> Dear All
> I have three data sets, X1, X2 and Y. X1 is data, X2 and Y were
> generated in (different) R programs. All three vectors have one column
> of 60 data points.
> I am using the code lm(Y~X1)$coef and lm(Y~X2)$coef. The first returns
> two values, an intercept and a slope, but the second returns 60 values.
> I suspect there is something in the "type" of X2 such that it forces the
> regression to do something different, but I can't work this out.

try

str(X2)

it is probably character vector or factor, so you need to transfer it to 
numeric.

see ?as.numeric and beware of factor properties (if X2 is factor)

Regards
Petr




> Please help!
> Lewis
> 
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