I define the following function: (Please don't wonder about the use of this function, this is just a simplified version of my actual function. And please don't spend your time in finding an alternate way of doing the same as the following does not exactly represent my function. I am only interested in a good explanation) > f1 = function(x,ties.method="average")rank(x,ties.method) > f1(c(1,1,2,4), ties.method="min") [1] 1.5 1.5 3.0 4.0 I don't know why it followed ties.method="average". Anyways I randomly tried the following: > f2 = function(x,ties.method="average")rank(x,ties.method=ties.method) > f2(c(1,1,2,4), ties.method="min") [1] 1 1 3 4 Now, it follows the ties.method="min" I don't see any explanation for this, however, I somehow mugged up that if I define it as in "f1", the ties.method in rank function takes its default value which is "average" and if I define as in "f2", it takes the value which is passed in "f2". But even all my mugging is wasted when I tested the following: > h = function(x, a=1)x^a > g1 = function(x, a=1)h(x,a) > g1(x=5, a=2) [1] 25 > g2 = function(x, a=1)h(x,a=a) > g2(x=5, a=2) [1] 25 Here in both the cases, "h" is taking the value passed through "g1", and "g2". Any comments/hints can be helpful. Regards Utkarsh
On Wed, 27 May 2009, utkarshsinghal wrote:> I define the following function: > (Please don't wonder about the use of this function, this is just a > simplified version of my actual function. And please don't spend your time in > finding an alternate way of doing the same as the following does not exactly > represent my function. I am only interested in a good explanation) > >> f1 = function(x,ties.method="average")rank(x,ties.method) >> f1(c(1,1,2,4), ties.method="min") > [1] 1.5 1.5 3.0 4.0 > > I don't know why it followed ties.method="average".Look at the arguments to rank()> args(rank)function (x, na.last = TRUE, ties.method = c("average", "first", "random", "max", "min")) When you do rank(x, ties.method) you are passing "min" as the second argument to rank(), which is the na.last argument, not the ties.method argument. This didn't give an error message because there weren't any NAs in your data. You want f1 = function(x,ties.method="average")rank(x,ties.method=ties.method) which gives> f1(c(1,1,2,4), ties.method="min")[1] 1 1 3 4 -thomas Thomas Lumley Assoc. Professor, Biostatistics tlumley at u.washington.edu University of Washington, Seattle
On Wed, 2009-05-27 at 19:41 +0530, utkarshsinghal wrote:> I define the following function: > (Please don't wonder about the use of this function, this is just a > simplified version of my actual function. And please don't spend your > time in finding an alternate way of doing the same as the following does > not exactly represent my function. I am only interested in a good > explanation) > > > f1 = function(x,ties.method="average")rank(x,ties.method) > > f1(c(1,1,2,4), ties.method="min") > [1] 1.5 1.5 3.0 4.0 > > I don't know why it followed ties.method="average".What is the second argument of rank? It is not ties.method. You passed "min" to na.last, not ties.method. You need to name the argument if you are not passing in all arguments and in the correct order.> Anyways I randomly tried the following: > > > f2 = function(x,ties.method="average")rank(x,ties.method=ties.method) > > f2(c(1,1,2,4), ties.method="min") > [1] 1 1 3 4 > Now, it follows the ties.method="min"Why randomly - ?rank tells you the argument is ties.method so you should set it to ties.method: times.method = ties.method in your call to rank.> > I don't see any explanation for this, however, I somehow mugged up that > if I define it as in "f1", the ties.method in rank function takes its > default value which is "average" and if I define as in "f2", it takes > the value which is passed in "f2".Because you aren't passing ties.method as the same argument in f1 and f2. In f1 you are passing ties.method to na.last, in f2 you do it correctly.> > But even all my mugging is wasted when I tested the following: > > > h = function(x, a=1)x^a > > g1 = function(x, a=1)h(x,a) > > g1(x=5, a=2) > [1] 25 > > > g2 = function(x, a=1)h(x,a=a) > > g2(x=5, a=2) > [1] 25 > > Here in both the cases, "h" is taking the value passed through "g1", and > "g2".Here there are only two arguments and you supplied them in the correct place when you supplied them un-named. HTH G> > Any comments/hints can be helpful. > > Regards > Utkarsh > > ______________________________________________ > R-help at 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.-- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 197 bytes Desc: This is a digitally signed message part URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20090527/2526a567/attachment-0002.bin>
The 'ties.method' argument to 'rank' is the *third* positional
argument to
'rank', so either you need to put it in the third position or you need
to
use a named argument.
The fact that the variable you're using to represent ties.method is called
ties.method is irrelevant. That is, this:
rank(x,ties.method)
is equivalent to
rank(x, na.last = ties.method)
which is not what you want.
You need to write
rank(x, ties.method = ties.method)
or (more concise but not as clear):
rank(x, , ties.method)
Hope this helps,
-s
On Wed, May 27, 2009 at 10:11 AM, utkarshsinghal <
utkarsh.singhal@global-analytics.com> wrote:
> I define the following function:
> (Please don't wonder about the use of this function, this is just a
> simplified version of my actual function. And please don't spend your
time
> in finding an alternate way of doing the same as the following does not
> exactly represent my function. I am only interested in a good explanation)
>
> > f1 = function(x,ties.method="average")rank(x,ties.method)
> > f1(c(1,1,2,4), ties.method="min")
> [1] 1.5 1.5 3.0 4.0
>
> I don't know why it followed ties.method="average".
> Anyways I randomly tried the following:
>
> > f2 =
function(x,ties.method="average")rank(x,ties.method=ties.method)
> > f2(c(1,1,2,4), ties.method="min")
> [1] 1 1 3 4
> Now, it follows the ties.method="min"
>
> I don't see any explanation for this, however, I somehow mugged up that
if
> I define it as in "f1", the ties.method in rank function takes
its default
> value which is "average" and if I define as in "f2", it
takes the value
> which is passed in "f2".
>
> But even all my mugging is wasted when I tested the following:
>
> > h = function(x, a=1)x^a
> > g1 = function(x, a=1)h(x,a)
> > g1(x=5, a=2)
> [1] 25
>
> > g2 = function(x, a=1)h(x,a=a)
> > g2(x=5, a=2)
> [1] 25
>
> Here in both the cases, "h" is taking the value passed through
"g1", and
> "g2".
>
> Any comments/hints can be helpful.
>
> Regards
> Utkarsh
>
> ______________________________________________
> 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.
>
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