Consider a study looking at the relationship of chili-pepper plant height to number of chilies produced.
Data was collected on all plants taller than 10cm. Initial look at the distribution of heights shows that most plants are on the short end, with a few reaching a max height of 150 cm as seen in a histogram. Taking the
log(plantheight) normalizes the distribution somewhat. However, looking at
log(plantheight - 10) gives a very nice looking normal distribution to the histogram.
First, is this a valid transformation? Shifting the values to zero, then taking the log?
Second, if not, what is the best way to deal with data that had been arbitrarily cut off in the experiment (no values below 10)?