RE: st: modifying egen to add a replace feature

[Pradipto Banerjee <pradipto.banerjee@adainvestments.com>]

That's exactly the issue I had. I had tried to use -replace- as an option, but Stata threw a error message saying that the variable is already defined.

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
Sent: Thursday, July 19, 2012 4:09 AM
To: statalist@hsphsun2.harvard.edu
Subject: Re: st: modifying egen to add a replace feature

Not so. Writing a new -egen- function so that it takes a -replace-
option is not the issue here. -egen- will throw out the call if -y- is
an existing variable before the function code is even entered. The
issue is cloning -egen- to do the replacement.

As I've signalled elsewhere, I think  it is easiest just to -drop-
what you don't want and/or do a -replace- afterwards.

Nick

On Thu, Jul 19, 2012 at 8:13 AM, Maarten Buis <maartenlbuis@gmail.com> wrote:
> On Wed, Jul 18, 2012 at 5:00 PM, Pradipto Banerjee wrote:
>> Is it possible to rewrite or modify egen, or create an ado file, such that I can simply write like this:
>>
>> bysort x: egen y = myfunc (y, a, b, ...), replace
>
> Yes, the logic behind the way -egen- works is that if you type -egen y
> = myfunc()-, -egen- will look for a file _gmyfunc.ado, which
> implements the function myfunc() and it also passes the option you
> have specified to that .ado file. So you can write your own -egen-
> functions. The easiest way to get started is to look at an existing
> similar function and addept that, e.g. look at -viewsource _gmean.ado.
>
>
*
*   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/

 This communication is for informational purposes only. It is not intended to be, nor should it be construed or used as, financial, legal, tax or investment advice or an offer to sell, or a solicitation of any offer to buy, an interest in any fund advised by Ada Investment Management LP, the Investment advisor.  Any offer or solicitation of an investment in any of the Funds may be made only by delivery of such Funds confidential offering materials to authorized prospective investors.  An investment in any of the Funds is not suitable for all investors.  No representation is made that the Funds will or are likely to achieve their objectives, or that any investor will or is likely to achieve results comparable to those shown, or will make any profit at all or will be able to avoid incurring substantial losses.  Performance results are net of applicable fees, are unaudited and reflect reinvestment of income and profits.  Past performance is no guarantee of future results. All f!
 inancial data and other information are not warranted as to completeness or accuracy and are subject to change without notice.

Any comments or statements made herein do not necessarily reflect those of Ada Investment Management LP and its affiliates. This transmission may contain information that is confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is strictly prohibited. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format.

*
*   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/