

Hi there,
I have a function which has a variable called show as an input:
richardson.grad < function(func, x, d=0.01, eps=1e4, r=6, show=F){
# do some things
if(show) {
cat("\n","first order approximations", "\n")
print(a.mtr, 12)
}
#do more things and return
}
The show variable is being used as a flag to show intermediate results.
Interestingly enough, I have downloaded a package recently which defines
the show variable as a function:
> show
standardGeneric for "show" defined from package "methods"
function (object)
standardGeneric("show")
<environment: 01676F7C>
Methods may be defined for arguments: object
>
Now, all of a sudden, the function I had defined earlier is scoping up
to this new value, and is thus not working:
> richardson.grad(function(x) x^2,2)
Error in if (show) { : argument is not interpretable as logical
>
I could always redefine show in richardson.grad to be something else but
something seems wrong: why is richardson.grad not looking up show's
value in the function ? How would I fix this ?
Thanks in advance,
Tolga
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Without a reproducible example one can only guess but
perhaps the problem is not show but that you have a variable
F. Try writing out F as FALSE.
On 2/16/06, Tolga Uzuner < [hidden email]> wrote:
> Hi there,
>
> I have a function which has a variable called show as an input:
>
> richardson.grad < function(func, x, d=0.01, eps=1e4, r=6, show=F){
> # do some things
> if(show) {
>
> cat("\n","first order approximations", "\n")
> print(a.mtr, 12)
>
>
> }
> #do more things and return
> }
>
> The show variable is being used as a flag to show intermediate results.
>
> Interestingly enough, I have downloaded a package recently which defines
> the show variable as a function:
>
> > show
> standardGeneric for "show" defined from package "methods"
>
> function (object)
> standardGeneric("show")
> <environment: 01676F7C>
> Methods may be defined for arguments: object
>
> >
>
> Now, all of a sudden, the function I had defined earlier is scoping up
> to this new value, and is thus not working:
>
> > richardson.grad(function(x) x^2,2)
> Error in if (show) { : argument is not interpretable as logical
> >
>
> I could always redefine show in richardson.grad to be something else but
> something seems wrong: why is richardson.grad not looking up show's
> value in the function ? How would I fix this ?
>
> Thanks in advance,
> Tolga
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rhelp> PLEASE do read the posting guide! http://www.Rproject.org/postingguide.html>
______________________________________________
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https://stat.ethz.ch/mailman/listinfo/rhelpPLEASE do read the posting guide! http://www.Rproject.org/postingguide.html


On Thu, 16 Feb 2006, Tolga Uzuner wrote:
> I have a function which has a variable called show as an input:
>
> richardson.grad < function(func, x, d=0.01, eps=1e4, r=6, show=F){
> # do some things
> if(show) {
>
> cat("\n","first order approximations", "\n")
> print(a.mtr, 12)
>
>
> }
> #do more things and return
> }
>
> The show variable is being used as a flag to show intermediate results.
>
> Interestingly enough, I have downloaded a package recently which defines
> the show variable as a function:
>
> > show
> standardGeneric for "show" defined from package "methods"
>
> function (object)
> standardGeneric("show")
> <environment: 01676F7C>
> Methods may be defined for arguments: object
>
> >
>
> Now, all of a sudden, the function I had defined earlier is scoping up
> to this new value, and is thus not working:
>
> > richardson.grad(function(x) x^2,2)
> Error in if (show) { : argument is not interpretable as logical
> >
>
> I could always redefine show in richardson.grad to be something else but
> something seems wrong: why is richardson.grad not looking up show's
> value in the function ? How would I fix this ?
You didn't spell out the logical value 'FALSE' which may
be causing your problem. Consider this alternative also...
richardson.grad < function(func,
x,
d = 0.01,
eps = 1e4,
r = 6,
verbose = getOption("verbose")) {
## do some things
if (verbose) {
cat("\n", "first order approximations:", "\n")
print(a.mtr, 12)
}
## do more things and return
}

SIGSIG  signature too long (core dumped)
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You are a star... that was it. Many thanks,
Tolga
Original Message
From: Gabor Grothendieck [mailto: [hidden email]]
Sent: 16 February 2006 20:24
To: Tolga Uzuner
Cc: [hidden email]
Subject: Re: [R] Problem with scoping a variable value
Without a reproducible example one can only guess but
perhaps the problem is not show but that you have a variable
F. Try writing out F as FALSE.
On 2/16/06, Tolga Uzuner < [hidden email]> wrote:
> Hi there,
>
> I have a function which has a variable called show as an input:
>
> richardson.grad < function(func, x, d=0.01, eps=1e4, r=6, show=F){
> # do some things
> if(show) {
>
> cat("\n","first order approximations", "\n")
> print(a.mtr, 12)
>
>
> }
> #do more things and return
> }
>
> The show variable is being used as a flag to show intermediate results.
>
> Interestingly enough, I have downloaded a package recently which defines
> the show variable as a function:
>
> > show
> standardGeneric for "show" defined from package "methods"
>
> function (object)
> standardGeneric("show")
> <environment: 01676F7C>
> Methods may be defined for arguments: object
>
> >
>
> Now, all of a sudden, the function I had defined earlier is scoping up
> to this new value, and is thus not working:
>
> > richardson.grad(function(x) x^2,2)
> Error in if (show) { : argument is not interpretable as logical
> >
>
> I could always redefine show in richardson.grad to be something else but
> something seems wrong: why is richardson.grad not looking up show's
> value in the function ? How would I fix this ?
>
> Thanks in advance,
> Tolga
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/rhelp> PLEASE do read the posting guide!
http://www.Rproject.org/postingguide.html>
______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/rhelpPLEASE do read the posting guide! http://www.Rproject.org/postingguide.html


Paul Roebuck wrote:
> On Thu, 16 Feb 2006, Tolga Uzuner wrote:
>
>
>>I have a function which has a variable called show as an input:
>>
>>richardson.grad < function(func, x, d=0.01, eps=1e4, r=6, show=F){
>># do some things
>> if(show) {
>>
>> cat("\n","first order approximations", "\n")
>> print(a.mtr, 12)
>>
>>
>> }
>>#do more things and return
>>}
>>
>>The show variable is being used as a flag to show intermediate results.
>>
>>Interestingly enough, I have downloaded a package recently which defines
>>the show variable as a function:
>>
>> > show
>>standardGeneric for "show" defined from package "methods"
>>
>>function (object)
>>standardGeneric("show")
>><environment: 01676F7C>
>>Methods may be defined for arguments: object
>>
>> >
>>
>>Now, all of a sudden, the function I had defined earlier is scoping up
>>to this new value, and is thus not working:
>>
>> > richardson.grad(function(x) x^2,2)
>>Error in if (show) { : argument is not interpretable as logical
>> >
>>
>>I could always redefine show in richardson.grad to be something else but
>>something seems wrong: why is richardson.grad not looking up show's
>>value in the function ? How would I fix this ?
>
>
> You didn't spell out the logical value 'FALSE' which may
> be causing your problem. Consider this alternative also...
>
> richardson.grad < function(func,
> x,
> d = 0.01,
> eps = 1e4,
> r = 6,
> verbose = getOption("verbose")) {
> ## do some things
> if (verbose) {
> cat("\n", "first order approximations:", "\n")
> print(a.mtr, 12)
> }
> ## do more things and return
> }
This is definitely the best solution, and Paul is right: you have to use
FALSE in preference to F (FALSE is a reserved word, F is not in R).
Now, you should know that show() *is* a generic function (it is the
default method for S4 objects), and it is a very bad idea to use it as
named argument for functions. I would suggest to use Paul's suggestion
instead, or to change it as 'show.it = FALSE', as a minimum.
Best,
Philippe Grosjean
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