Re: [R] Where are usages like == 2L documented?
I think your suggestions below indicate a difference in documentation
philosophy between us. I believe that things should be documented well
in one place, and it should be easy to find that one place; you seem to
be suggesting spreading out bits and pieces of documentation to many places.
The disadvantage of the many-place style is that it is hard to look up
details. I may remember seeing somewhere various rules about something,
but if it isn't clear where to look for it again, I will have trouble
finding it.
The weakness of the one-place style is that it isn't always easy to find
that one place. R documentation especially suffers from this, because
it is hard to find things in the manuals if you're looking in the help()
system. I think the solution is to make it easier to find things in the
manuals, rather than repeating bits and pieces of the manuals all across
the help system.
One way to do this is to link the manuals into the help system, and I
did some work on this last year, but unfortunately this requires a newer
version of Texinfo than we are allowed to use because of FSF license
restrictions.
Duncan Murdoch
On 16/11/2009 9:09 PM, Steven McKinney wrote:
-Original Message-
From: Gabor Grothendieck [mailto:ggrothendi...@gmail.com]
Sent: Monday, November 16, 2009 4:52 PM
To: Duncan Murdoch
Cc: Steven McKinney; R Help
Subject: Re: [R] Where are usages like == 2L documented?
On Mon, Nov 16, 2009 at 7:25 PM, Duncan Murdoch murd...@stats.uwo.ca
wrote:
On 16/11/2009 6:47 PM, Steven McKinney wrote:
?NumericConstants
will bring up a help page that mentions
All other numeric constants start with a digit or period and are
either a
decimal or hexadecimal constant optionally followed by L.
and
An numeric constant immediately followed by L is regarded as an
integer
number when possible (and with a warning if it contains a .).
The word integer in the above sentence of the NumericConstants help
page is hyperlinked to the integer() function page. There is then no
example or discussion of L there.
but I haven't found discussion of it anywhere else in the help
pages.
Others may know what other help pages discuss this.
I'm surprised that the help page invoked from
?integer
does not discuss this. Anyone know why not?
This is part of the syntax of the language. It has nothing to do
with the
integer() function, which is what ?integer is asking about.
It might be useful to have a SeeAlso to NumericConstants on that help
page for those who looked up ?integer thinking it might be about
integer constants.
Yes, additional discussion of L would be very valuable. I've had
several people ask me about usages, as this original poster did.
I think that increased use of L has outpaced updating of help entries.
Given that L is appearing in more places, I'd like to request additional
discussion of it and examples using it in help pages.
class(1L)
[1] integer
storage.mode(1L)
[1] integer
Since integer is the term often associated with this language construct,
that seems a natural place to say something about it, and direct users
to other appropriate help pages.
The help page for storage.mode() shows an example with 1i in it,
could 1L please also be added? (1.0 or 1. would also be useful.)
cex3 - c(NULL,1,1:1,1i,list(1),data.frame(x=1),
pairlist(pi), c, lm, formals(lm)[[1]], formals(lm)[[2]],
y~x,expression((1))[[1]], (y~x)[[1]],
expression(x - pi)[[1]][[1]])
The L language construct is often used in length checks such as
in the sample() function if (length(x) == 1L ...
The length() function help page discusses
The default method currently returns an integer of length 1.
again with the integer hyperlinked to the integer() help page.
Since length() therefore can only assess integer lengths
from 0 to about 2^31 - 1 it would be helpful to discuss this
integer L construct and the range of values that can be expressed
with mode integer more fully somewhere in one of these help topics.
sample
function (x, size, replace = FALSE, prob = NULL)
{
if (length(x) == 1L is.numeric(x) x = 1) {
if (missing(size))
size - x
.Internal(sample(x, size, replace, prob))
}
else {
if (missing(size))
size - length(x)
x[.Internal(sample(length(x), size, replace, prob))]
}
}
environment: namespace:base
Best
Steve McKinney
__
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.
Re: [R] Where are usages like == 2L documented?
Patrick reminded me that it's also in The R Inferno, another document that I need to read again. So now, a more particular semi-question: x - 1L y - 1 z - 1.0 class(x) # integer class(y) # numeric class(z) # numeric x == 1 x == 1L y == 1 z == 1 # all test TRUE Just to clarify, I think the steps above prove it, but *in a test* like x == 1 the test is for the contents, not the storage mode, not for a combination of storage mode and contents. So... The reason for defining the notion of L is smaller storage space, and more generally, for use anytime one wants explictly an integer for whatever reason? Are there other reasons, for instance, ways it saves lines of code? Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA On 11/17/09 4:20 AM, Patrick Burns pbu...@pburns.seanet.com wrote: 'The R Inferno' page 75. Patrick Burns patr...@burns-stat.com +44 (0)20 8525 0696 http://www.burns-stat.com (home of The R Inferno and A Guide for the Unwilling S User) Bryan Hanson wrote: Gurus: I keep seeing other people¹s code that contain ideas like If (x == 2L) X[-1L] X - 1L I have some idea of what¹s going on, but where is the use of concepts like ³2L² documented? Thanks, Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA __ 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.
Re: [R] Where are usages like == 2L documented?
On Tue, 17 Nov 2009, Bryan Hanson wrote: Patrick reminded me that it's also in The R Inferno, another document that I need to read again. So now, a more particular semi-question: x - 1L y - 1 z - 1.0 class(x) # integer class(y) # numeric class(z) # numeric NB: identical(x, y) is TRUE, so they behave the same. x == 1 x == 1L y == 1 z == 1 # all test TRUE Just to clarify, I think the steps above prove it, but *in a test* like x == 1 the test is for the contents, not the storage mode, not for a combination of storage mode and contents. Not really: the operands are coerced to a common type and then tested for equality. From the help page for == If the two arguments are atomic vectors of different types, one is coerced to the type of the other, the (decreasing) order of precedence being character, complex, numeric, integer, logical and raw. So... The reason for defining the notion of L is smaller storage space, and more generally, for use anytime one wants explictly an integer for whatever reason? Are there other reasons, for instance, ways it saves lines of code? It avoids coercion. The test x == 1 requires x to be coerced from integer to double, and foo[1] requires '1' to be coerced from double to integer. There is little if any gain in storage space for small integer vectors over small double vectors, but all those coercions can create a lot of new objects which need to be garbage-collected. Also, 2L is simpler to write and to read than as.integer(2) (and avoids a funtion call and a coercion). Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA On 11/17/09 4:20 AM, Patrick Burns pbu...@pburns.seanet.com wrote: 'The R Inferno' page 75. Patrick Burns patr...@burns-stat.com +44 (0)20 8525 0696 http://www.burns-stat.com (home of The R Inferno and A Guide for the Unwilling S User) Bryan Hanson wrote: Gurus: I keep seeing other people¹s code that contain ideas like If (x == 2L) X[-1L] X - 1L I have some idea of what¹s going on, but where is the use of concepts like ³2L² documented? Thanks, Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA __ 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. -- Brian D. Ripley, rip...@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595__ 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.
Re: [R] Where are usages like == 2L documented?
On 16/11/2009 7:52 PM, Gabor Grothendieck wrote: On Mon, Nov 16, 2009 at 7:25 PM, Duncan Murdoch murd...@stats.uwo.ca wrote: On 16/11/2009 6:47 PM, Steven McKinney wrote: ?NumericConstants will bring up a help page that mentions All other numeric constants start with a digit or period and are either a decimal or hexadecimal constant optionally followed by L. and An numeric constant immediately followed by L is regarded as an integer number when possible (and with a warning if it contains a .). but I haven't found discussion of it anywhere else in the help pages. Others may know what other help pages discuss this. I'm surprised that the help page invoked from ?integer does not discuss this. Anyone know why not? This is part of the syntax of the language. It has nothing to do with the integer() function, which is what ?integer is asking about. It might be useful to have a SeeAlso to NumericConstants on that help page for those who looked up ?integer thinking it might be about integer constants. I've added 1L, 1i and 0x1 as aliases for NumericConstants instead. Duncan Murdoch __ 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.
Re: [R] Where are usages like == 2L documented?
On Nov 16, 2009, at 6:22 PM, Bryan Hanson wrote: Gurus: I keep seeing other people’s code that contain ideas like If (x == 2L) X[-1L] X - 1L I have some idea of what’s going on, but where is the use of concepts like “2L” documented? Not sure where exactly, and it would depend on where you learned R. The integer data type information and notation should have been found among the material where you learned about numeric, character, logical, that sort of basic notion. -- David Winsemius, MD Heritage Laboratories West Hartford, CT __ 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.
Re: [R] Where are usages like == 2L documented?
Bryan Hanson wrote: Gurus: I keep seeing other people¹s code that contain ideas like If (x == 2L) X[-1L] X - 1L I have some idea of what¹s going on, but where is the use of concepts like ³2L² documented? In the R Language Definition manual. In this case, look in section 3.1.1, Constants. Duncan Murdoch Thanks, Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA __ 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.
Re: [R] Where are usages like == 2L documented?
?NumericConstants will bring up a help page that mentions All other numeric constants start with a digit or period and are either a decimal or hexadecimal constant optionally followed by L. and An numeric constant immediately followed by L is regarded as an integer number when possible (and with a warning if it contains a .). but I haven't found discussion of it anywhere else in the help pages. Others may know what other help pages discuss this. I'm surprised that the help page invoked from ?integer does not discuss this. Anyone know why not? Best Steve McKinney -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Bryan Hanson Sent: Monday, November 16, 2009 3:23 PM To: R Help Subject: [R] Where are usages like == 2L documented? Gurus: I keep seeing other people¹s code that contain ideas like If (x == 2L) X[-1L] X - 1L I have some idea of what¹s going on, but where is the use of concepts like ³2L² documented? Thanks, Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA __ 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.
Re: [R] Where are usages like == 2L documented?
On 16/11/2009 6:47 PM, Steven McKinney wrote: ?NumericConstants will bring up a help page that mentions All other numeric constants start with a digit or period and are either a decimal or hexadecimal constant optionally followed by L. and An numeric constant immediately followed by L is regarded as an integer number when possible (and with a warning if it contains a .). but I haven't found discussion of it anywhere else in the help pages. Others may know what other help pages discuss this. I'm surprised that the help page invoked from ?integer does not discuss this. Anyone know why not? This is part of the syntax of the language. It has nothing to do with the integer() function, which is what ?integer is asking about. Duncan Murdoch Best Steve McKinney -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Bryan Hanson Sent: Monday, November 16, 2009 3:23 PM To: R Help Subject: [R] Where are usages like == 2L documented? Gurus: I keep seeing other people¹s code that contain ideas like If (x == 2L) X[-1L] X - 1L I have some idea of what¹s going on, but where is the use of concepts like ³2L² documented? Thanks, Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA __ 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-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.
Re: [R] Where are usages like == 2L documented?
On Mon, Nov 16, 2009 at 7:25 PM, Duncan Murdoch murd...@stats.uwo.ca wrote: On 16/11/2009 6:47 PM, Steven McKinney wrote: ?NumericConstants will bring up a help page that mentions All other numeric constants start with a digit or period and are either a decimal or hexadecimal constant optionally followed by L. and An numeric constant immediately followed by L is regarded as an integer number when possible (and with a warning if it contains a .). but I haven't found discussion of it anywhere else in the help pages. Others may know what other help pages discuss this. I'm surprised that the help page invoked from ?integer does not discuss this. Anyone know why not? This is part of the syntax of the language. It has nothing to do with the integer() function, which is what ?integer is asking about. It might be useful to have a SeeAlso to NumericConstants on that help page for those who looked up ?integer thinking it might be about integer constants. __ 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.
Re: [R] Where are usages like == 2L documented?
As the OP, I will say that I had deduced that it probably was a way of specifying type integer, so I went to the ?integer page hoping for further info. I agree there should be some kind of short comment or see also at that page. I've been a self-taught user of R for about a year and a half, and this is one of the better hidden pieces of information. I had looked at the R Lang document, and probably should again for some additional ideas, but that was a long time ago. I did an RSiteSearch(1L) but not surprisingly this returns many uses of the feature, not the definition, at least not in the first few pages. Thanks for the tips. Bryan * Bryan Hanson Acting Chair Professor of Chemistry Biochemistry DePauw University, Greencastle IN USA On 11/16/09 7:52 PM, Gabor Grothendieck ggrothendi...@gmail.com wrote: On Mon, Nov 16, 2009 at 7:25 PM, Duncan Murdoch murd...@stats.uwo.ca wrote: On 16/11/2009 6:47 PM, Steven McKinney wrote: ?NumericConstants will bring up a help page that mentions All other numeric constants start with a digit or period and are either a decimal or hexadecimal constant optionally followed by L. and An numeric constant immediately followed by L is regarded as an integer number when possible (and with a warning if it contains a .). but I haven't found discussion of it anywhere else in the help pages. Others may know what other help pages discuss this. I'm surprised that the help page invoked from ?integer does not discuss this. Anyone know why not? This is part of the syntax of the language. It has nothing to do with the integer() function, which is what ?integer is asking about. It might be useful to have a SeeAlso to NumericConstants on that help page for those who looked up ?integer thinking it might be about integer constants. __ 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.
Re: [R] Where are usages like == 2L documented?
-Original Message-
From: Gabor Grothendieck [mailto:ggrothendi...@gmail.com]
Sent: Monday, November 16, 2009 4:52 PM
To: Duncan Murdoch
Cc: Steven McKinney; R Help
Subject: Re: [R] Where are usages like == 2L documented?
On Mon, Nov 16, 2009 at 7:25 PM, Duncan Murdoch murd...@stats.uwo.ca
wrote:
On 16/11/2009 6:47 PM, Steven McKinney wrote:
?NumericConstants
will bring up a help page that mentions
All other numeric constants start with a digit or period and are
either a
decimal or hexadecimal constant optionally followed by L.
and
An numeric constant immediately followed by L is regarded as an
integer
number when possible (and with a warning if it contains a .).
The word integer in the above sentence of the NumericConstants help
page is hyperlinked to the integer() function page. There is then no
example or discussion of L there.
but I haven't found discussion of it anywhere else in the help
pages.
Others may know what other help pages discuss this.
I'm surprised that the help page invoked from
?integer
does not discuss this. Anyone know why not?
This is part of the syntax of the language. It has nothing to do
with the
integer() function, which is what ?integer is asking about.
It might be useful to have a SeeAlso to NumericConstants on that help
page for those who looked up ?integer thinking it might be about
integer constants.
Yes, additional discussion of L would be very valuable. I've had
several people ask me about usages, as this original poster did.
I think that increased use of L has outpaced updating of help entries.
Given that L is appearing in more places, I'd like to request additional
discussion of it and examples using it in help pages.
class(1L)
[1] integer
storage.mode(1L)
[1] integer
Since integer is the term often associated with this language construct,
that seems a natural place to say something about it, and direct users
to other appropriate help pages.
The help page for storage.mode() shows an example with 1i in it,
could 1L please also be added? (1.0 or 1. would also be useful.)
cex3 - c(NULL,1,1:1,1i,list(1),data.frame(x=1),
pairlist(pi), c, lm, formals(lm)[[1]], formals(lm)[[2]],
y~x,expression((1))[[1]], (y~x)[[1]],
expression(x - pi)[[1]][[1]])
The L language construct is often used in length checks such as
in the sample() function if (length(x) == 1L ...
The length() function help page discusses
The default method currently returns an integer of length 1.
again with the integer hyperlinked to the integer() help page.
Since length() therefore can only assess integer lengths
from 0 to about 2^31 - 1 it would be helpful to discuss this
integer L construct and the range of values that can be expressed
with mode integer more fully somewhere in one of these help topics.
sample
function (x, size, replace = FALSE, prob = NULL)
{
if (length(x) == 1L is.numeric(x) x = 1) {
if (missing(size))
size - x
.Internal(sample(x, size, replace, prob))
}
else {
if (missing(size))
size - length(x)
x[.Internal(sample(length(x), size, replace, prob))]
}
}
environment: namespace:base
Best
Steve McKinney
__
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.
