[R] problem with simple if() statement

Philippe Grosjean
Mon, 06 Feb 2006 10:22:06 -0000

Norman Goodacre wrote:
> the following code apprantely, for some grand old reason, induces a syntax
error:
>
>   if (seq[i] = "A") m <- trans[1,]
>
>   where seq is a vector and trans is a matrix. I cannot for the life of me
see why this is wrong. Syntax error is:
>
>   Error: syntax error in "if (seq[i] ="
>
>   Sincerely,
>
>   Norman Goodacre

Please, read "An Introduction to R" provided with any version of R.
The
correct syntax for an equality condition is "==", not "=",
so:

 > if (seq[i] == "A") ....

Best,

Philippe Grosjean