On Nov 9, 2011, at 12:04 PM, Rich Shepard wrote:

 I would appreciate pointers on what I should read to understand this
output:

summary(lm(TDS ~ Cond + Ca + Cl + Mg + Na + SO4))

I don't see a data= argument specified, so you are telling lm() that your workspace has individual vectors by those names in the formula. That is not what is implied by hte rest of your message.


Call:
lm(formula = TDS ~ Cond + Ca + Cl + Mg + Na + SO4)

Residuals:
ALL 1 residuals are 0: no residual degrees of freedom!

Coefficients: (6 not defined because of singularities)
           Estimate Std. Error t value Pr(>|t|)
(Intercept)      125         NA      NA       NA
Cond              NA         NA      NA       NA
Ca                NA         NA      NA       NA
Cl                NA         NA      NA       NA
Mg                NA         NA      NA       NA
Na                NA         NA      NA       NA
SO4               NA         NA      NA       NA

Residual standard error: NaN on 0 degrees of freedom
 (63 observations deleted due to missingness)

When I look at the summary for the data frame used for this model I do not see an excessive number of missing values or indications why there are no residual degrees of freedom. The same model applied to 8 other data frames
did not produce similar results.

Puzzled,

Rich

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to