R help - Mar 2013 - using reserved words in R, and reuse variable names in different functions

Hi list,
I am writing several functions and running out variable names.  I am using
words such as "t", "c", "matrix" to keep the
notation same as formulas I am
using.

For example I have,

unnormalized <- function(t, x, y){
    val <- rnorm(t, mean=x, var=y)
    return(val)
}

metropolis <- function(t, c, x, y){
    den1 <- unnormalized(t, mean=x, sd=y)
    den2 <- unnormalized(c, mean=x, sd=y)
    if(den1 < den2)
       return(a)
    else
       return(b)
}

for(i in 1: 100){
    matrix <- c()
    matrix[i] <- metroplis(1, 2, 3, 4)
}
Here, I reused letter "t" and "c", and the word
"matrix".  Could this cause
any potential problems?

Thanks in advance,
Mike

	[[alternative HTML version deleted]]

On Mar 1, 2013, at 1:56 PM, C W wrote:
> Hi list,
> I am writing several functions and running out variable names.  I am using
> words such as "t", "c", "matrix" to keep the
notation same as formulas I am
> using.
> 
> For example I have,
> 
> unnormalized <- function(t, x, y){
>    val <- rnorm(t, mean=x, var=y)
>    return(val)
> }
> 
> metropolis <- function(t, c, x, y){
>    den1 <- unnormalized(t, mean=x, sd=y)
>    den2 <- unnormalized(c, mean=x, sd=y)
>    if(den1 < den2)
>       return(a)
>    else
>       return(b)
> }
> 
> for(i in 1: 100){
>    matrix <- c()
>    matrix[i] <- metroplis(1, 2, 3, 4)
> }
> Here, I reused letter "t" and "c", and the word
"matrix".  Could this cause
> any potential problems?
 Whatever problems you are having at the moment (and they appear to be many) are
not  due to using existing function names as data-object names. You are asked to
report the error messages you get with your code problems, and those messages I
found to be reasonably informative for the first 5 errors I found.

-- 
David Winsemius
Alameda, CA, USA

Yes, it can cause problems. And speaking for myself, I'd say it's not
worth the risk, because it's easy enough to find alternative variable
names that are close enough to the notation of your formulas that
remembering should be no problem. For example, "tt", "cc",
and "mmatrix"
might do it.

-Don

-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062





On 3/1/13 1:56 PM, "C W" <tmrsg11 at gmail.com> wrote:

Hi list,
I am writing several functions and running out variable names.  I am using
words such as "t", "c", "matrix" to keep the
notation same as formulas I am
using.

For example I have,

unnormalized <- function(t, x, y){
    val <- rnorm(t, mean=x, var=y)
    return(val)
}

metropolis <- function(t, c, x, y){
    den1 <- unnormalized(t, mean=x, sd=y)
    den2 <- unnormalized(c, mean=x, sd=y)
    if(den1 < den2)
       return(a)
    else
       return(b)
}

for(i in 1: 100){
    matrix <- c()
    matrix[i] <- metroplis(1, 2, 3, 4)
}
Here, I reused letter "t" and "c", and the word
"matrix".  Could this cause
any potential problems?

Thanks in advance,
Mike

	[[alternative HTML version deleted]]

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