Using the local macro in loop

[Nathanael Lucas]

I am getting caught up in the code at the last point and was wanting some advice,

I have a data of breast cancer
Two Categorical Variables
stage - Stage 1, 2, or 3
type - Ductal (1), Medullary (2). Mucinous (3), Papillary (4)

One Indicator Variable
sex - Male (1), Female (2)

One continous variable
survtime

I want to work out the average survival in stage by sex and type by sex,

I have tried to code but get tripped up at the end,

The following works and gives me overall means stratified by sex

local vars stage type
foreach x in local vars {
forvalues i=1/2 {
summarize survtime if sex==`i' , detail
return list
}
}


But when I try to split the groups by their individual categories I keep getting errors

local vars stage type
foreach x in local vars {
forvalues i=1/2 {
forvalues j=1/4{
capture noisily summarize survtime if sex==`i' & `x”==`j', detail
return list
}
}
}

`x” invalid name ???

Thanks

[William Lisowski]

Without reviewing your code to be sure it will do what you want once it works, in the line

capture noisily summarize survtime if sex==`i' & `x”==`j', detail

you have the wrong quotation mark following the x - you want

capture noisily summarize survtime if sex==`i' & `x'==`j', detail

as you have after all your other local macro references.

[Nathanael Lucas]

Hi William,

That comes up with
- local not found
- vars not found

The forvalues using j may not be the best technique?
I'm trying some other options but not having much luck, essentially I need to create a formula to summarize a continuous variable stratified by two categorical variables,

Thanks for your help,

[Nick Cox]

See

help foreach

to see that you have a choice between

local vars stage type
foreach x of local vars {

and

foreach x in stage type {

That said it sounds as if

bysort sex stage: summarize survtime, detail
bysort sex type: summarize survtime, detail

is more or less what you are trying to do.

[William Lisowski]

Please note that the incorrect foreach command that Nick discusses in post #4 appears in your post #1 in both sets of code - including the set that you said works.

It appears that the code you presented in post #1 is not the code that worked when you ran it.

Please review the Statalist FAQ linked to from the top of the page, as well as from the Advice on Posting link on the page you have used to create each of your posts. Note especially sections 9-12 on how to best pose your question.

Section 12.1 is particularly pertinent

12.1 What to say about your commands and your problem

Say exactly what you typed and exactly what Stata typed (or did) in response. N.B. exactly!

as is Section 12.3 on the use of code delimiters [CODE] and [/CODE] to present code and output copied from the results window.

The more you help others understand your problem, the more likely others are to be able to help you solve your problem.