st: Rolling Returns and simple loop

["kelly johnson" <econometrics@hotmail.com>]

Hi,

Suppose I have data liek the following:

Date=date
A, B, C are closing prices for stocks A,B, and C respectively.

How can I write a simple program to do the following:

(I) calculate the 10 day rolling returns
(II) caclulate a ratio=10day rollign returns/std. dev.
(II) loop so as to repeat this caclulation across other variables (B,C, 
etc.)

Thank you!

kj

date	A	B	C
05 Aug 05	43.34	45.27	33.52
04 Aug 05	43.83	45.46	34.06
03 Aug 05	44.55	46.11	34.51
02 Aug 05	44.75	46.51	33.88
01 Aug 05	43.61	44.93	33.3299
29 Jul 05	41.78	45.15	33.34
28 Jul 05	42.02	45.68	34.01
27 Jul 05	41.99	43.65	34.29
26 Jul 05	40.42	37.74	34.15
25 Jul 05	40.88	37.95	33.85
22 Jul 05	41.02	37.95	33.53
.
.
.
21 Jul 03	42.1	37.95	32.94

_________________________________________________________________
Don�t just search. Find. Check out the new MSN Search! 
http://search.msn.click-url.com/go/onm00200636ave/direct/01/

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/