Displaying 20 results from an estimated 37 matches for "infis".
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2023 Apr 12
1
converting a character matrix into numeric....
Dear Rui,
Not working. I have entirely removed the column containing % but am still bootless:
> head(coredata(INFYTX))
INFY Historical Data INFY Historical Data INFY Historical Data INFY Historical Data
[1,] "47.26" "44.28" "47.56" "44.28"
[2,] "46.30" "44.92"
2023 Apr 12
1
converting a character matrix into numeric....
Isn't this like trying to tie up the horse after it has left the barn? Why not figure all this out _before_ converting to xts?
On April 12, 2023 12:29:49 PM PDT, akshay kulkarni <akshay_e4 at hotmail.com> wrote:
>Dear Rui,
> Not working. I have entirely removed the column containing % but am still bootless:
>
>> head(coredata(INFYTX))
> INFY
2023 Apr 12
1
converting a character matrix into numeric....
?s 19:57 de 12/04/2023, akshay kulkarni escreveu:
> Dear members,
> I have an xts object:
>
>> head(INFYTX)
> INFY Historical Data INFY Historical Data.1 INFY Historical Data.2
> 2003-04-16 "47.26" "44.28" "47.56"
> 2003-04-17 "46.30" "44.92"
2023 Apr 12
1
converting a character matrix into numeric....
Dear members,
I have an xts object:
> head(INFYTX)
INFY Historical Data INFY Historical Data.1 INFY Historical Data.2
2003-04-16 "47.26" "44.28" "47.56"
2003-04-17 "46.30" "44.92" "46.53"
2003-04-21 "45.82"
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 ?
> 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:
>
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
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
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.
> >
2024 Sep 05
2
BUG: atan(1i) / 5 = NaN+Infi ?
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 were some changes in handling of complex numbers. But it looks like a bug.
Sincerely,
Leonard
[[alternative HTML version deleted]]
2024 Sep 05
0
BUG: atan(1i) / 5 = NaN+Infi ?
On 2024-09-05 6:12 p.m., Leo Mada wrote:
> Dear Duncan,
>
> Here is also the missing information:
> R version 4.4.1 (2024-06-14 ucrt)
> Platform: x86_64-w64-mingw32/x64
> Running under: Windows 10 x64 (build 19045)
>
> Regarding the results:
> atan(1i)
> #?0+Infi
> Re(atan(1i))
> # 0
> Im(atan(1i))
> #? Inf
>
> 0 + Inf i is a valid complex number:
2024 Sep 06
1
BUG: atan(1i) / 5 = NaN+Infi ?
I expect that atan(1i) = (0 + infinity i) and that atan(1i)/5 = (0 +
infinity i)/5 = (0 + infinity i).
Here's what I get in C:
(0,1) = (0, 1)
atan((0,1)) = (0, inf)
atan((0,1))/5 = (0, inf)
Note the difference between I*infinity = (0,1)*infinity =
(0*infinity,1*infinity) = (NaN,infinity)
and (0,infinity)/5 = (0/5,infinity/5) = (0,infinity).
The former involves multiplying 0 by infinity, which
2024 Sep 06
1
BUG: atan(1i) / 5 = NaN+Infi ?
The thing is that real*complex, complex*real, and complex/real are not
"complex arithmetic"
in the requisite sense. The complex numbers are a vector space over
the reals, and
complex*real and real*complex are vector*scalar and scalar*vector.
For example, in the Ada programming language, we have
function "*" (Left, Right : Complex) return Complex;
function "*" (Left :
2024 Sep 06
1
BUG: atan(1i) / 5 = NaN+Infi ?
On 2024-09-06 12:44 a.m., Richard O'Keefe wrote:
> I expect that atan(1i) = (0 + infinity i) and that atan(1i)/5 = (0 +
> infinity i)/5 = (0 + infinity i).
> Here's what I get in C:
> (0,1) = (0, 1)
> atan((0,1)) = (0, inf)
> atan((0,1))/5 = (0, inf)
>
> Note the difference between I*infinity = (0,1)*infinity =
> (0*infinity,1*infinity) = (NaN,infinity)
> and
2024 Sep 06
1
BUG: atan(1i) / 5 = NaN+Infi ?
>>>>> Richard O'Keefe
>>>>> on Fri, 6 Sep 2024 17:24:07 +1200 writes:
> The thing is that real*complex, complex*real, and complex/real are not
> "complex arithmetic" in the requisite sense.
> The complex numbers are a vector space over the reals,
Yes, but they _also_ are field (and as others have argued mathematically only
2024 Sep 06
1
BUG: atan(1i) / 5 = NaN+Infi ?
G.5.1 para 2 can be found in the C17 standard -- I actually have the
final draft not the published standard. It's in earlier standards, I
just didn't check earlier standards. Complex arithmetic was not in
the first C standard (C89) but was in C99.
The complex numbers do indeed form a field, and Z*W invokes an
operation in that field when Z and W are both complex numbers. Z*R
and R*Z,
2003 May 02
6
openssh 3.6.1_p2 problem with pam (fwd)
----- Forwarded message from Andrea Barisani <lcars at infis.univ.trieste.it> -----
Date: Fri, 2 May 2003 14:01:33 +0200
From: Andrea Barisani <lcars at infis.univ.trieste.it>
To: openssh at openssh.com
Subject: openssh 3.6.1_p2 problem with pam
Hi, I've just updated to openssh 3.6.1_p2 and I notice this behaviour:
# ssh -l lcars mybox
[2 se...
2002 Feb 19
2
cdf of the standard normal distribution
Dear Experts,
I need to calculate the cdf of the standard normal distribution, i.e.
H(x) = 1/sqrt(2*pi) integral(exp(-z^2/2) dz), where z is b/w -infi to
infi.
I know there should be a way to do it in R, but did not know to do it.
I'd appreciate any help you could offer.
Charlie Liu
Graduate student intern at EPA/ECO
2024 Sep 06
0
BUG: atan(1i) / 5 = NaN+Infi ?
It seems to me that the documentation of R's complex class & R's atan function do not tell us what to expect, so (as others have suggested), some additional notes are needed. I think that mathematically atan(1i) should be NA_complex_, but R seems not to use any mathematically standard compactification of the complex plane (and I'm not sure that IEEE does either).
Incidentally, the
2010 Jul 01
5
ROC curve in R
Hi,
i have a fairly large amount of genomic data. I have created a dataframe
which has "Reference" as one column and "Variation" as another. I want to
plot a ROC curve based on these 2 columns. I have serached the R manual but
I could not understand. Can anybody help me with the R code for plotting ROC
curve.
Thnx
ashu6886
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