Displaying 20 results from an estimated 6000 matches similar to: "Best way to preallocate numeric NA array?"
2009 May 09
5
Reading large files quickly
I'm finding that readLines() and read.fwf() take nearly two hours to
work through a 3.5 GB file, even when reading in large (100 MB) chunks.
The unix command wc by contrast processes the same file in three
minutes. Is there a faster way to read files in R?
Thanks!
2005 Oct 16
2
Animated lissajous
Here's some code to make lissajous dance. I've attached a small sample
GIF.
Cheers,
Rob Steele
robsteele at yahoo dot com
plot.lissajous = function(omega.x, omega.y, delta = 0, num.thetas = 200)
{
thetas = seq(0, 2 * pi, length = num.thetas)
xs = sin(omega.x * thetas + delta)
ys = cos(omega.y * thetas)
plot(xs, ys, type = 'l', lwd = 3, ann = FALSE, axes = FALSE)
}
2017 May 19
2
Inconsistency in handling of numeric input with %d by sprintf
Consider
#as.numeric for emphasis
sprintf('%d', as.numeric(1))
# [1] "1"
vs.
sprintf('%d', NA_real_)
> Error in sprintf("%d", NA_real_) :
invalid format '%d'; use format %f, %e, %g or %a for numeric object
>
I understand the error is correct, but if it works for other numeric input,
why doesn't R just coerce NA_real_ to NA_integer_?
2009 Jun 03
2
Create a time interval from a single time variable
I am trying to set up a data set for a survival analysis with time-varying covariates. The data is already in a long format, but does not have a variable to signify the stopping point for the interval. The variable DaysEnrolled is the variable I would like to use to form this interval. This is what I have now:
ID Age DaysEnrolled HAZ WAZ WHZ Food onARV
2023 Nov 06
1
c(NA, 0+1i) not the same as c(as.complex(NA), 0+1i)?
Hmm, it is not actually at odds with help(c), it is just that the autocoercion works different that it used to, so that
as.complex(NA) == as.complex(NA_real) == NA_real_+0i)
which now differs from
NA_complex
although both print as NA.
I haven't been quite alert when this change was discussed, but it does look a bit unfortunate that usage patterns like c(NA, 0+1i) does not give complex NA
2017 May 23
2
Inconsistency in handling of numeric input with %d by sprintf
I initially thought this is "documented behaviour". ?sprintf says:
Numeric variables with __exactly integer__ values will be coerced to
integer. (emphasis mine).
Turns out this only works when the first value is numeric and not NA, as
shown by the following example:
> sprintf("%d", as.numeric(c(NA,1)))
Error in sprintf("%d", as.numeric(c(NA, 1))) :
invalid
2017 May 23
2
Inconsistency in handling of numeric input with %d by sprintf
https://github.com/Rdatatable/data.table/issues/2171
The fix was easy, it's just surprising to see the behavior change almost on
a whim. Just wanted to point it out in case this is unknown behavior, but
Evan seems to have found this as well.
On Tue, May 23, 2017 at 12:00 PM, Michael Chirico <michaelchirico4 at gmail.com
> wrote:
> Astute observation. And of course we should be
2020 May 23
2
Should 0L * NA_integer_ be 0L?
I don't see this specific case documented anywhere (I also tried to search
the r-devel archives, as well as I could); the only close reference
mentions NA & FALSE = FALSE, NA | TRUE = TRUE. And there's also this
snippet from R-lang:
In cases where the result of the operation would be the same for all
> possible values the NA could take, the operation may return this value.
>
2023 Nov 08
1
c(NA, 0+1i) not the same as c(as.complex(NA), 0+1i)?
So, to summarize, the open questions are:
(1) Should as.complex(NA_character_) give complex(r=NA_real_, i=0)
instead of NA_complex_?
(2) Should the first argument in c(NA, x) and c(NA_integer_, x),
where typeof(x) == "complex", be promoted to complex(r=NA_real_, i=0)
instead of NA_complex_?
My opinions:
(1) No. The imaginary part of the
2023 Nov 09
1
c(NA, 0+1i) not the same as c(as.complex(NA), 0+1i)?
>>>>> Mikael Jagan
>>>>> on Wed, 8 Nov 2023 11:13:18 -0500 writes:
> So, to summarize, the open questions are:
> (1) Should as.complex(NA_character_) give complex(r=NA_real_, i=0)
> instead of NA_complex_?
> (2) Should the first argument in c(NA, x) and c(NA_integer_, x),
> where typeof(x) == "complex", be promoted
2005 Nov 23
2
Dancing lissajous
We can't post images here so I've put up a web page to show off a neat
little animation in R:
http://www.geocities.com/robsteele/
Adios!
2023 Apr 14
1
Possible inconsistency between `as.complex(NA_real_)` and the docs
Hi all,
Surprisingly (at least to me), `as.complex(NA_real_)` results in
`complex(real = NA_real_, imaginary = 0)` rather than `NA_complex_`.
It seems to me that this goes against the docs of `as.complex()`,
which say this in the Details section:
"Up to R versions 3.2.x, all forms of NA and NaN were coerced to a
complex NA, i.e., the NA_complex_ constant, for which both the real
and
2016 Jul 16
1
sample() fails with double or integer NA input of length one
Hi,
I have discovered that sample() fails with an uninformative error
message when the x argument is a single NA of type double or integer.
I can reproduce the problem with the following code:
base::sample(NA)
# NA is of logical type above
base::sample(NA_character_)
base::sample(NA_complex_)
base::sample(NA_real_)
base::sample(NA_integer_)
The last two lines throw the following error:
Error
2023 Nov 05
2
c(NA, 0+1i) not the same as c(as.complex(NA), 0+1i)?
This is another follow-up to the thread from September "Recent changes to
as.complex(NA_real_)".
A test in data.table was broken by the changes for NA coercion to complex;
the breakage essentially comes from
c(NA, 0+1i)
# vs
c(as.complex(NA), 0+1i)
The former is the output we tested against; the latter is essentially (via
coerceVector() in C) what's generated by our
2016 Jun 10
2
Fixed updates for EL5 / EL6
> Please go download -8 and test it.
Sorry to be ignorant but how do I do that in EL6?
Thanks!
2023 Nov 06
1
c(NA, 0+1i) not the same as c(as.complex(NA), 0+1i)?
>>>>> Michael Chirico
>>>>> on Sun, 5 Nov 2023 09:41:42 -0800 writes:
> This is another follow-up to the thread from September
> "Recent changes to as.complex(NA_real_)".
> A test in data.table was broken by the changes for NA
> coercion to complex; the breakage essentially comes from
> c(NA, 0+1i)
> # vs
2015 May 17
1
The function cummax() seems to have a bug.
Hi,
The function cummax() seems to have a bug.
> x <- c(NA, 0)
> storage.mode(x) <- "integer"
> cummax(x)
[1] NA 0
The correct result of this case should be NA NA. The mistake in [
https://github.com/wch/r-source/blob/trunk/src/main/cum.c#L130-L136] may be
the reason.
Best Regards,
Dongcan
--
Dongcan Jiang
Team of Search Engine & Web Mining
School of Electronic
2023 Nov 07
1
c(NA, 0+1i) not the same as c(as.complex(NA), 0+1i)?
Thanks Martin. My hang-up was not on what the outcome of as.complex(NA)
should be, but rather, how I should read code like c(x, y) generally. Till
now, I have thought of it like 'c(x, y)' is c(as(x, typeof(y)), y)` when
"type(y) > type(x)". Basically in my mind, "coercion" in R <->
as.<newtype>(.) (or coerceVector() in C).
So I tracked down the source
2009 May 29
1
png() error in recent R-devel on Windows
Hi,
Tested with the latest r-devel snapshot build for Windows (2009-05-28 r48663):
> png("test.png")
Error in png("test.png") : invalid value of 'fillOddEven'
The png() function is defined like this:
> png
function (filename = "Rplot%03d.png", width = 480, height = 480,
units = "px", pointsize = 12, bg = "white", res = NA,
2008 Mar 26
5
S4 slot with NA default
Hi
How do I specify an S4 class with a slot that is potentially numeric,
but NA
by default? I want the slot to be NA until I calculate its value
(an expensive operation, not needed for all applications). When
its value is
known, I will create a new object with the correct value inserted in
the slot.
I want "NA" to signify "not known".
My attempt fails because