Truncating Y-axis with -rcap-

[Kevin Rowe]

Hello,

I am generating vertical bar graphs with vertical 95% CIs using -twoway (bar var1 var2) (rcap var1hi var1lo)-. My CIs are quite large, and so to fit them on the graph, Stata expands the y-axis and shrinks the bars substantially.

I would like to reduce the range of the y-axis so that the whiskers appear to extend beyond the range of the graph. It seems to me that getting the whiskers to actually extend beyond the range of the axis will be very difficult (I've seen some discussion on similar problems here: http://www.stata.com/statalist/archi.../msg00963.html).

Instead, can I produce whiskers that have a horizontal cross on the bottom only so that I can cut them off at my preferred y, making them appear as if they go beyond the range of the y-axis?

Thanks.

[Nick Cox]

Not as far as I know. You could fudge this by using rspike and hyphens or dashes as marker labels.

Stata's attitude, here and elsewhere, is that you shouldn't want to truncate representations in this way. Some would even regard them as unethical.

I'd search the forum for discussions of these plots under headings such as "dynamite plots" and "detonator plots". Some scientists use them, but many more statistically-minded people regard them very poorly The situation you describe usually arises with very small samples with large or erratic variability. When that happens, it is usually better to plot the raw data.