Displaying 20 results from an estimated 2000 matches similar to: "return value of {....}"
2024 Sep 05
2
BUG: atan(1i) / 5 = NaN+Infi ?
atan(1i) -> 0 + Inf i
complex(1/5) -> 0.2 + 0i
atan(1i) -> (0 + Inf i) * (0.2 + 0i)
-> 0*0.2 + 0*0i + Inf i * 0.2 + Inf i * 0i
infinity times zero is undefined
-> 0 + 0i + Inf i + NaN * i^2
-> 0 + 0i + Inf i - NaN
-> NaN + Inf i
I am not sure how complex arithmetic could arrive at another answer.
I advise against messing with infinities... use atan2() if you don't
2024 Sep 05
3
BUG: atan(1i) / 5 = NaN+Infi ?
On 2024-09-05 4:23 p.m., Leo Mada via R-help wrote:
> Dear R Users,
>
> Is this desired behaviour?
> I presume it's a bug.
>
> atan(1i)
> # 0+Infi
>
> tan(atan(1i))
> # 0+1i
>
> atan(1i) / 5
> # NaN+Infi
There's no need to involve atan() and tan() in this:
> (0+Inf*1i)/5
[1] NaN+Infi
Why do you think this is a bug?
Duncan Murdoch
2024 Sep 05
1
BUG: atan(1i) / 5 = NaN+Infi ?
Dear Bert,
These behave like real divisions/multiplications:
complex(re=Inf, im = Inf) * 5
# Inf+Infi
complex(re=-Inf, im = Inf) * 5
# -Inf+Infi
The real division / multiplication should be faster and also is well behaved. I was expecting R to do the real division/multiplication on a complex number. Which R actually does for these very particular cases; but not when only Im(x) is Inf.
2024 Sep 05
1
BUG: atan(1i) / 5 = NaN+Infi ?
> complex(real = 0, imaginary = Inf)
[1] 0+Infi
> Inf*1i
[1] NaN+Infi
>> complex(real = 0, imaginary = Inf)/5
[1] NaN+Infi
See the Note in ?complex for the explanation, I think. Duncan can correct
if I'm wrong.
-- Bert
On Thu, Sep 5, 2024 at 3:20?PM Leo Mada <leo.mada at syonic.eu> wrote:
> Dear Bert,
>
> These behave like real divisions/multiplications:
>
2023 Oct 16
1
Create new data frame with conditional sums
If one makes the reasonable assumption that Pct is much larger than
Cutoff, sorting Cutoff is the expensive part e.g O(nlog2(n) for
Quicksort (n = length Cutoff). I believe looping is O(n^2). Jeff's
approach using findInterval may be faster. Of course implementation
details matter.
-- Bert
On Mon, Oct 16, 2023 at 4:41?AM Leonard Mada <leo.mada at syonic.eu> wrote:
>
> Dear
2023 Oct 16
1
Create new data frame with conditional sums
Dear Jason,
The code could look something like:
dummyData = data.frame(Tract=seq(1, 10, by=1),
?? ?Pct = c(0.05,0.03,0.01,0.12,0.21,0.04,0.07,0.09,0.06,0.03),
?? ?Totpop = c(4000,3500,4500,4100,3900,4250,5100,4700,4950,4800))
# Define the cutoffs
# - allow for duplicate entries;
by = 0.03; # by = 0.01;
cutoffs <- seq(0, 0.20, by = by)
# Create a new column with cutoffs
dummyData$Cutoff
2024 Jun 02
2
R code for overlapping variables -- count
Dear Shadee,
If you have a data.frame with the following columns:
n = 100; # population size
x = data.frame(
??????Sex = sample(c("M","F"), n, T),
??????Country = sample(c("AA", "BB", "US"), n, T),
??????Income = as.factor(sample(1:3, n, T))
)
# Dummy variable
ONE = rep(1, nrow(x))
r = aggregate(ONE ~ Sex + Income + Country, length, data = x)
2024 Jun 02
1
Tools to modify highlighted areas in pdf documents?
? Sat, 1 Jun 2024 16:16:23 +0000
Leo Mada via R-help <r-help at r-project.org> ?????:
> When highlighting pdf-documents with Microsoft Edge, the bounding box
> is sometimes misplaced, and quite ugly so. It also lacks the ability
> to draw lines or arrows.
>
> On the other hand, I did not get used to Acrobat Reader: it usually
> involves much more effort to add specific
2024 Jan 30
2
Use of geometric mean for geochemical concentrations
Dear Rich,
It depends how the data is generated.
Although I am not an expert in ecology, I can explain it based on a biomedical example.
Certain variables are generated geometrically (exponentially), e.g. MIC or Titer.
MIC = Minimum Inhibitory Concentration for bacterial resistance
Titer = dilution which still has an effect, e.g. serially diluting blood samples;
Obviously, diluting the
2024 Sep 05
2
BUG: atan(1i) / 5 = NaN+Infi ?
Perhaps
> Inf*1i
[1] NaN+Infi
clarifies why it is *not* a bug.
(Boy, did that jog some long dusty math memories :-) )
-- Bert
On Thu, Sep 5, 2024 at 2:48?PM Duncan Murdoch <murdoch.duncan at gmail.com>
wrote:
> On 2024-09-05 4:23 p.m., Leo Mada via R-help wrote:
> > Dear R Users,
> >
> > Is this desired behaviour?
> > I presume it's a bug.
> >
2010 Apr 19
2
How to pass a list of parameters into a function
Does anyone know how to pass a list of parameters into a function?
for example:
somefun=function(x1,x2,x3,x4,x5,x6,x7,x8,x9){
ans=x1+x2+x3+x4+x5+x6+x7+x8+x9
return(ans)
}
somefun(1,2,3,4,5,6,7,8,9)
# I would like this to work:
temp=c(x3=3,x4=4,x5=5,x6=6,x7=7,x8=8,x9=9)
somefun(x1=1,x2=2,temp)
# OR I would like this to work:
temp=list(x3=3,x4=4,x5=5,x6=6,x7=7,x8=8,x9=9)
2005 Feb 14
1
how can i make my program faster
Hello,
right now, i have a program to collect data into a table. right now, my table is
table1 <- data.frame(trial = NA, x = NA, y = NA)
for each time when i want to add data into my data, i have to copy data of table into an array for each column, and then i add new data into my array, then i copy my array into the table one column by one column. For example
temptrial <- table1$trial;
2023 Oct 21
1
Issue from R-devel: subset on table
My mistake!
It does actually something else, which is incorrect. One could still use
(although the code is more difficult to read):
subset(tmp <- table(sample(1:10, 100, T)), tmp > 10)
Sincerely,
Leonard
On 10/21/2023 10:26 PM, Leonard Mada wrote:
> Dear List Members,
>
> There was recently an issue on R-devel (which I noticed only very late):
>
2023 Mar 19
2
lexical scoping for scripts......
Dear Duncun,
What if there is no interactive "session" running? I will be running my scripts automatically from crontab in Linux.
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
________________________________
From: Duncan Murdoch <murdoch.duncan at gmail.com>
Sent: Monday, March 20, 2023 12:20 AM
To: akshay kulkarni <akshay_e4 at hotmail.com>; R
2023 Mar 19
1
lexical scoping for scripts......
Again, the answer is "interactivity does not matter".
On March 19, 2023 12:54:28 PM PDT, akshay kulkarni <akshay_e4 at hotmail.com> wrote:
>Dear Jeff,
> I will not be running R command in the shell prompt. So there is no banner, no > prompt. Just running "myscript.R" from the shell prompt. or from crontab in Linux. I think you get the
2023 Mar 19
1
lexical scoping for scripts......
On 19/03/2023 2:55 p.m., akshay kulkarni wrote:
> Dear Duncun,
> ? ? ? ? ? ? ? ? ? ? ? ? ?What if there is no interactive "session"
> running? I will be running my scripts automatically from crontab in Linux.
I was talking about the session that is created for the duration of the
BATCH run, not some other session that may be running in another
process. Sorry for the
2023 Jan 12
4
return value of {....}
Hello Akshay,
R is quite inspired by LISP, where this is a common thing. It is not in fact that {...} returned something, rather any expression evalulates to some value, and for a compound statement that is the last evaluated expression.
{...} might be seen as similar to LISPs (begin ...).
Now this is a very different thing compared to {...} in something like C, even if it looks or behaves
2023 Jan 09
3
return value of {....}
Dear Valentin,
But why should {....} "return" a value? It could just as well evaluate all the expressions and store the resulting objects in whatever environment the interpreter chooses, and then it would be left to the user to manipulate any object he chooses. Don't you think returning the last, or any value, is redundant? We are living in the 21st century
2017 Dec 15
6
something weird has happened....!!!!!!!!!!
dear Members,
Today something weird has happened on my R console. I have attached two screenshots of the same vector in my R console but they differ.
Also one of my function returns negative values, even after double checking the code, which should return only positive values..
Whats wrong..? Reinstall R?
Thanks for help....
AKSHAY M KULKARNI
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2023 Mar 19
1
lexical scoping for scripts......
Dear Jeff,
I will not be running R command in the shell prompt. So there is no banner, no > prompt. Just running "myscript.R" from the shell prompt. or from crontab in Linux. I think you get the context.....
thanking you,
yours sincerely
AKSHAY M KULKARNI
________________________________
From: Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
Sent: Monday, March