Re: [R] Pasting with Quotes
Thank you both so much for your help! I ended up using
bquote(expression(...)), and it's working perfectly!
On Sat, May 5, 2012 at 1:05 PM, David Winsemius wrote:
>
> On May 5, 2012, at 2:42 PM, Josh Browning wrote:
>
> Hello useRs!
>>
>> So, I have a random question. I'm trying to build a character string,
>> then
>> evaluate it.
>>
>
> Actually you are trying to build a language object , a call or an
> expression. You might have gotten further with:
>
> do.call(ksvm, list( ... named arguments ...)
>
>
> I think an example would be the easiest way to explain:
>>
>>
>> kern.vec = c("rbfdot","polydot")
>> for( j in 1:length( kern.vec ) )
>> {
>> formula= paste("ksvm( ind ~ . ,
>> data=d.temp[,c(ind_col,dep_**cols)], kernel =",kern.vec[j],",
>> prob.model=T )")
>> svm= eval( parse( text=formula ) )
>>...
>> }
>>
>>
>> The problem I always seem to have is that in the formula, I need to have
>> quotes around "rbfdot" (for example). But, when I paste the expression
>> together, it removes the quotes. Is there a better way to do this (or at
>> least a way around this problem)? My method seems a bit kludgy :)
>>
>
> Perhaps looking at either:
>
> ?substitute
> ?bquote
>
>
> kern.vec = c("rbfdot","polydot")
> for( j in 1:length( kern.vec ) )
> {
> formula= bquote(expression( ksvm( ind ~ . ,
> data=d.temp[,c(ind_col,dep_**cols)], kernel =.(kern.vec[j] ) ,
> prob.model=T ) ))
> print(formula)
> }
>
> expression(ksvm(ind ~ ., data = d.temp[, c(ind_col, dep_cols)],
>kernel = "rbfdot", prob.model = T))
> expression(ksvm(ind ~ ., data = d.temp[, c(ind_col, dep_cols)],
>kernel = "polydot", prob.model = T))
>
> Notice that the values for kern.vec are 'character' which is what you
> passed them (and what you seem to be requesting. If you wanted the values
> of those named objects you might try get(). (I'm not a user of
> whatever package has `ksvm` in it, so I'm not aware of whether 'rbfdot' is
> supposed to be a character value as a parameter or if those are named
> objects, and I'm not running out to identify the package and then to locate
> a working example to test the eval-result. Those are details you should
> have provided.)
>
>>
>>
>
> --
>
> David Winsemius, MD
> West Hartford, CT
>
>
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Re: [R] Pasting with Quotes
On May 5, 2012, at 2:42 PM, Josh Browning wrote:
Hello useRs!
So, I have a random question. I'm trying to build a character
string, then
evaluate it.
Actually you are trying to build a language object , a call or an
expression. You might have gotten further with:
do.call(ksvm, list( ... named arguments ...)
I think an example would be the easiest way to explain:
kern.vec = c("rbfdot","polydot")
for( j in 1:length( kern.vec ) )
{
formula= paste("ksvm( ind ~ . ,
data=d.temp[,c(ind_col,dep_cols)], kernel =",kern.vec[j],",
prob.model=T )")
svm= eval( parse( text=formula ) )
...
}
The problem I always seem to have is that in the formula, I need to
have
quotes around "rbfdot" (for example). But, when I paste the
expression
together, it removes the quotes. Is there a better way to do this
(or at
least a way around this problem)? My method seems a bit kludgy :)
Perhaps looking at either:
?substitute
?bquote
kern.vec = c("rbfdot","polydot")
for( j in 1:length( kern.vec ) )
{
formula= bquote(expression( ksvm( ind ~ . ,
data=d.temp[,c(ind_col,dep_cols)], kernel =.(kern.vec[j] ) ,
prob.model=T ) ))
print(formula)
}
expression(ksvm(ind ~ ., data = d.temp[, c(ind_col, dep_cols)],
kernel = "rbfdot", prob.model = T))
expression(ksvm(ind ~ ., data = d.temp[, c(ind_col, dep_cols)],
kernel = "polydot", prob.model = T))
Notice that the values for kern.vec are 'character' which is what you
passed them (and what you seem to be requesting. If you wanted the
values of those named objects you might try get(). (I'm not a
user of whatever package has `ksvm` in it, so I'm not aware of whether
'rbfdot' is supposed to be a character value as a parameter or if
those are named objects, and I'm not running out to identify the
package and then to locate a working example to test the eval-result.
Those are details you should have provided.)
--
David Winsemius, MD
West Hartford, CT
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Pasting with Quotes
What's the "big picture" of what you're trying to do? eval(parse(text
= )) is often a less than optimal idea.
Some guesses:
Are you trying to construct a formula object (in the strict sense of
something that you pass to a modeling function)?
Maybe lazy evaluation of the deparse(substitute(x)) flavor might help here?
Michael
On Sat, May 5, 2012 at 2:42 PM, Josh Browning
wrote:
> Hello useRs!
>
> So, I have a random question. I'm trying to build a character string, then
> evaluate it. I think an example would be the easiest way to explain:
>
>
> kern.vec = c("rbfdot","polydot")
> for( j in 1:length( kern.vec ) )
> {
> formula = paste("ksvm( ind ~ . ,
> data=d.temp[,c(ind_col,dep_cols)], kernel =",kern.vec[j],", prob.model=T )")
> svm = eval( parse( text=formula ) )
> ...
> }
>
>
> The problem I always seem to have is that in the formula, I need to have
> quotes around "rbfdot" (for example). But, when I paste the expression
> together, it removes the quotes. Is there a better way to do this (or at
> least a way around this problem)? My method seems a bit kludgy :)
>
> Thanks for all your help!
>
> Josh
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[R] Pasting with Quotes
Hello useRs!
So, I have a random question. I'm trying to build a character string, then
evaluate it. I think an example would be the easiest way to explain:
kern.vec = c("rbfdot","polydot")
for( j in 1:length( kern.vec ) )
{
formula= paste("ksvm( ind ~ . ,
data=d.temp[,c(ind_col,dep_cols)], kernel =",kern.vec[j],", prob.model=T )")
svm= eval( parse( text=formula ) )
...
}
The problem I always seem to have is that in the formula, I need to have
quotes around "rbfdot" (for example). But, when I paste the expression
together, it removes the quotes. Is there a better way to do this (or at
least a way around this problem)? My method seems a bit kludgy :)
Thanks for all your help!
Josh
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
