I am calling on the R-help crew once again. The CD4Per for each subject should
be the same for each subject based on a 90 day window either side of the known
value. For example, ID 2931 should have a CD4Per of 36 at 0, 34, and 62
DaysEnrolled. Any ideas how to do this without a loop?
ID DaysEnrolled CD4Per
10 1436 0 NA
11 2931 0 NA
12 2931 34 36
13 2931 62 NA
14 2931 125 NA
15 2931 181 NA
16 2931 273 NA
277 3802 0 NA
278 3802 28 NA
279 3802 54 NA
280 3802 69 NA
281 3802 96 NA
282 3802 110 NA
283 3802 138 27
284 3802 141 NA
285 3802 166 NA
286 3802 194 NA
287 3802 222 NA
288 3802 223 NA
289 3802 267 NA
290 3802 288 NA
291 3802 327 35
292 3802 354 NA
293 3802 397 NA
294 3802 424 NA
295 3802 448 NA
296 3802 466 NA
297 3802 508 NA
298 3802 516 NA
299 3802 536 NA
300 3802 566 NA
301 3802 609 NA
302 3802 662 NA
303 3802 729 NA
304 3802 764 NA
305 3802 785 NA
306 3802 813 NA
307 3802 841 NA
308 3802 869 NA
309 3802 897 37
310 3802 974 NA
311 3802 1002 NA
312 3802 1030 NA
379 3806 0 NA
380 3806 22 15
381 3806 30 NA
382 3806 43 NA
383 3806 50 NA
384 3806 57 NA
385 3806 64 NA
Adrian Katschke
Biostatistician
IU Department of Medicine
Division of Biostatistics
akatschk at iupui.edu
317-278-6665