st: Combining graphs

[Paul <paul@iheta.com>]

I have a very large file of 2.3 million hospital admissions, and am using stata v 13.1 on a MacBook Pro

I want to create three bar charts of the hospital cost of complications for hip replacement, using three different icd codes for the hip procedures. I want to then  combine the three in one graph. 

This seemed straightforward with the following loop:

gen i=1

foreach v of varlist HIP1824Px HIP1836Px HIP1819Px {

 graph bar total_episd_amt if LOS>0 & hospital_group=="" & separation_fy=="2010/11", over (COMPTOT, relabel(2 "Complication" 1 "NoComplication")) over(`v', relabel(2 "`v'"  1 "  Other admissions")) title ("Mean episode amount overnight stays, public hospitals 2010/11") subtitle ("`v' with/without complications") name(HIP`i')

 replace i=i+1

 }

The error message is : HIP1 is not a memory graph

I have tried various combinations of the saving and name conventions, including double quotation marks around the `i' in the name, but none work.

Any  ideas, please?

Paul Gross