I would actually go with this:
bits=c(1, 0, 1, 1, 0)
paste("X", which(bits==1), sep=".",collapse="+")
No need for the vars variable. Though admittedly it breaks down if
bits is identically 0.
Haris Skiadas
Department of Mathematics and Computer Science
Hanover College
On May 6, 2008, at 3:11 PM, Jorge Ivan Velez wrote:
Hi Esmail,
Try this:
vars=c('X.1', 'X.2', 'X.3', 'X.4', 'X.5')
bits=c(1, 0, 1, 1, 0)
paste(vars[which(bits==1)],collapse="+")
HTH,
Jorge
On Tue, May 6, 2008 at 3:06 PM, Esmail Bonakdarian
<[EMAIL PROTECTED]>
wrote:
Hello,
Still a newbie with R, though I have learned a lot from reading
this list. I'm hoping someone can help with this question:
I have two vectors, one for variables, and one for bits.
I want to build a string (really a formula) based on the values in my
vector of 1s and 0s in bits. If I have a one, I want to include the
corresponding entry in the vars vector, otherwise ignore it. Of
course
the "bits" vector will not stay the same.
So for example:
vars=c('X.1', 'X.2', 'X.3', 'X.4', 'X.5')
bits=c(1, 0, 1, 1, 0)
ones=which(bits==1)
should yield:
"X.1 + X.3 + X.4"
where as
bits=c(1, 1, 0, 0, 0)
would yield
"X.1 + X.2"
the "which" operator gives me the index values, is there an easy and
*efficient* way to build this string so that I can pass it on to glm?
I can probably hack some ugly code together to do this, but it won't
be efficient, and it won't be elegant :-)
Can anyone help?
Thanks!
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