Message-ID: <E66794E69CFDE04D9A70842786030B931B919133@PA-MBX04.na.tibco.com>
Date: 2013-03-21T14:49:47Z
From: William Dunlap
Subject: Help on indicator variables
In-Reply-To: <CA+wU8YAMJiufOL+JBnOLVxJUyJth-tt0Q8=7W5LGa+W9rKqAMw@mail.gmail.com>
I would use a logical variable, with values TRUE and FALSE, instead
of a numeric indicator. E.g., I find the following easier to follow
bL <- ABS==1 | DEFF==1
if (any(bL)) { do.this() }
than
bN <- ifelse(ABS == 1 | DEFF == 1, 1, 0)
if (any(bN == 1)) { do.this() }
The latter leaves me wondering what other values bN might have;
the former makes it clear this is a TRUE/FALSE dichotomy.
Logicals get converted to numbers (FALSE->0, TRUE->1) when used in
arithmetic so you can do, e.g., mean(bL) to see what proportion of
your cases satisfy the condition.
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
> Of Tasnuva Tabassum
> Sent: Thursday, March 21, 2013 6:03 AM
> To: R help
> Subject: [R] Help on indicator variables
>
> I have two indicator variables ABS and DEFF. I want to create another
> indicator variable which will take value 1 if either ABS=1 or DEFF=1.
> Otherwise, it will take value 0. How can I make that?
>
> [[alternative HTML version deleted]]
>
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