[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: pooling data

From   "Nick Cox" <>
To   <>
Subject   st: RE: pooling data
Date   Mon, 26 May 2008 17:12:20 +0100

-stack- and -reshape- are both fairly high-level commands. -stack- is
(extremely roughly!) a special case of -reshape-. A rough guess is that
-reshape- imposes slightly more interpretative overhead than -stack-,
but I've done no testing. It's also probably true that any specific
-reshape- only uses a small fraction of the code. 

In principle, I guess you could always write a more "efficient", meaning
machine faster, alternative for any specific -reshape long-, at the cost
of leaving out various checks that could be crucial in many
circumstances. The human time cost of that would probably be far greater
than any real saving. 


Tunga Kantarci

I have a panel variable: that is it has time series and cross section
I would like to produce a histogram regardless of the time dimension.
That is, I would like to pool the time dimension and then produce a

To do this, I used the following command: 

reshape long variablename, i(id) j(number)

I suppose one can also use the "stack" command.

I am wondering if this is an inefficient way of pooling data.
Is there a better workaround to pool data?  

*   For searches and help try:

© Copyright 1996–2023 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index