[R] Looking for transformation to overcome heterogeneity of variances

[Peter Dalgaard]

"Paul Smith" <phhs80 at gmail.com> writes:

> Dear All
> 
> My data consists in 96 groups, each one with 10 observations. Levene's
> test suggests that the variances are not equal, and therefore I have
> tried to apply the classical transformations to have homocedasticity
> in order to be able to use ANOVA. Unfortunately, no transformation
> that I have used transforms my data into data with homocedasticity.
> The histogram of variances is at
> 
> http://phhs80.googlepages.com/hist1.png
> 
> Is someone able to suggest to me a transformation to overcome the
> problem of heterocedasticity?

Not based on that information. Try the following instead:

fit <- lm(y~g)
par(mfrow=c(2,2)); plot(fit)

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