Re: st: Log Transformation of Variable

[Nick Cox <njcoxstata@gmail.com>]

I'm pleased that you now have apparently got what you wanted. But note that

-ln(variable)

is not correctly described in words as multiplying by the negative of
the logarithm. There is no multiplication involved here. That quantity
is the negative logarithm of the variable.

I am curious also that the extra constant exp(1) ~ 2.71828 is wanted
here. For example, it makes no different to the linearity of any
relationship or the skewness or kurtosis of any distribution.

Nick

On Sun, Feb 27, 2011 at 7:25 PM, Melissa King <melissakng@gmail.com> wrote:

> Thank you for your responses to my post. As Fernando, Nick and Gordon
> pointed out, I did not want to multiply my function by (-log-e), which
> was a typo. I wanted to multiply each data point by the negative of
> log, and THEN subtract out the base of the log. I eventually figured
> out how to generate the transformed variable using the following:
>
> generate transformed_variable = -ln(variable) - exp(1)
>
> Sorry to have submitted such a confusing post. This is what happens
> when you work too many 16-hour days in a row. Next time I will sleep
> on it before wasting anyone's time. Rich, this question actually had
> nothing to to with my own work; it had to do with some unusual data my
> husband Marty was working with.
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