On Sat, 8 Oct 2011, Hélio Guilherme wrote:
While running an ANOVA linear regression got this untranslated
message:
anova: the x variables must be discrete
OK, I'll figure what to do about that. But note that the "anova"
command is not really a case of linear regression -- it's an
alternative (in general an inferior one, I would say) to regression.
The "x variables" are the treatment variable and (for two-way ANOVA)
the "block" or control variable, and it's inherent in the ANOVA
approach that these must be discrete (they're just category codes).
For reference, here's a trivial ANOVA example:
<hansl>
open data9-7
series season= WINTER? 1: SPRING? 2: SUMMER? 3: 4
anova QNC season
# compare regression, more informative
ols QNC WINTER SPRING SUMMER FALL
</hansl>
Allin