how to write an easy code for this?

[Yao Zhao]

Simply speaking, I have these 6 variables in my data set and want to do:

ttest preaddition == postaddition
ttest predeletion == postdeletion
ttest pretotal == posttotal

I guess I need to use foreach and local.

[Rich Goldstein]

if that is your total number of tests, a loop won't help much but:

foreach ln in addition deletion total {
   ttest pre`ln' == post`ln'
}

[Yao Zhao]

Thank you!