<>
The questions are difficult/impossible to answer without an example dataset.
Still, I have a hunch that you should look at
*************
help reshape
*************
Quite often, -reshape- makes seemingly intractable problems surprisingly
easy...
The -if- commands (like "if dgc`chron_cyc1'_1b_cde == 1" ) that you use
evaluate only the first observations in your dataset, nothing else...
HTH
Martin
-----Ursprüngliche Nachricht-----
Von: [email protected]
[mailto:[email protected]] Im Auftrag von David Sabapathy
Gesendet: Montag, 20. Juli 2009 18:45
An: [email protected]
Betreff: st: Nested loops by observation
I have a question related to the FAQ "if command versus if qualifier". For
each observation in a dataset I need to perform a series of nested loops
("forvalues" / "if") on a longitudinal variable set to evaluate whether a
"chronic" medication condition exists. That is, each observation contains
multiple years of survey information (the dgc* variables below) which is
being analyzed and if a chronic condition exists a new variable "chronic" is
set to 1. I can't use the nested commands as shown below in a simplified
version of the code as they only work on the first observation. However I
also can't use this nested code as a qualifier (i.e. replace chronic = 1 if
...) as syntax does not appear to allow this type of nesting. Is there
anyway I can step through observations one by one with this nested code?
Any other possible solutions?
Thank you for any help you can provide,
David
gen chronic = .
forvalues cycle = 1(1)4 {
if dgc`cycle'_1b_cde == 0 { // if no med use
cycle i
local chron_cyc1 = `cycle' + 1
if dgc`chron_cyc1'_1b_cde == 1 { // if med use cycle_i+1
local chron_cyc2 = `cycle' + 2
if dgc`chron_cyc2'_1b_cde == 1 { // if med use cycle_i+2
if dhc`chron_cyc1'_age >=65 & dhc`chron_cyc2'_age >=65 {
// "replace chronic = 2"
}
else {
// "replace chronic = 1"
}
}
}
}
}
This message and any attached documents are only for the use of the intended
recipient(s), are confidential and may contain privileged information. Any
unauthorized review, use, retransmission, or other disclosure is strictly
prohibited. If you have received this message in error, please notify the
sender immediately, and then delete the original message. Thank you.
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
