similar to: Missing values

Hi Everyone, I'm trying to write selfStart non-linear models for use with nls. In these models some combinations of parameter values are illegal; the function value is undefined. That's OK when calling the function directly [e.g. SSmodel(x, pars...)]; I return an appropriate non-value such as NA or Inf. However, when called from nls [e.g. nls(y~SSmodel(x, pars...), ...)] those

Hi Gabriel, The point is that it *visually* displays as NA, but is.na() still responds as FALSE. When I (and I am sure many people) see an NA, we then use is.na(). If we see Inf displayed, we then use is.infinite(). With as.Date() this breaks down. I'm not arguing that as.Date(Inf) should be coerced to NA. I'm arguing that as.Date(Inf) should be *visually* displayed as Inf (i.e. the

> > I just wanted to point out that if x = inf the result of x * 0 is in > indeterminate form so reducing it to zero would give the wrong result > in that case. Yes, thanks for the hint, but someone else already pointed out that nan*0 is also not 0. I have a special application where inf and nan will not occur, therefore I will patch my local llvm to optimize floats more

>>>>> Gabriel Becker >>>>> on Tue, 5 Mar 2019 22:01:37 -0800 writes: > On Tue, Mar 5, 2019 at 9:54 PM Richard White <w at rwhite.no> wrote: >> Hi Gabriel, >> >> The point is that it *visually* displays as NA, but is.na() still >> responds as FALSE. >> >> When I (and I am sure many people)

Hi Jochen, I just wanted to point out that if x = inf the result of x * 0 is in indeterminate form so reducing it to zero would give the wrong result in that case. Thanks, Javier On 3/3/2010 8:56 AM, Jochen Wilhelmy wrote: > Hi! > > > >> sin/cos etc should already be handled by lib/Analysis/ConstantFolding.cpp. >> >> > Thanks for the hint and it

Under windows, R supports IEEE floating point arithmetic, but doesn't allow conversion of Inf and NaN from character to numeric. R> is.nan(NaN) [1] TRUE R> as.numeric(as.character(NaN)) [1] NA Warning message: NAs introduced by coercion R> is.infinite(Inf) [1] TRUE R> as.numeric(as.character(Inf)) [1] NA Warning message: NAs introduced by coercion whereas under Linux R>

Hi! > sin/cos etc should already be handled by lib/Analysis/ConstantFolding.cpp. > Thanks for the hint and it works! Now I have a new Problem: I have this function: float foo(float a, float b) { float x = a * b * 0.0f; return cos(0.5) * sin(0.5) * x; }; after compiling it with clang (cpp mode) and renaming _ZSt3sinf to sin and _ZSt3cosf to cos I get the following: define

>>>>> 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

Dear R, I have two questions: 1, Why both R and Matlab give 0*Inf==NaN? To my knowledge, it should be zero mathematically. Am I right? 2, I need to calculate e.g. exp(a)/(exp(b)+c), where both a and b are very large numbers (>>1000, e.g a=1000, b=1007, and c=5). R gives me NaN when I use the following command: > exp(1000)/(exp(1007)+5) [1] NaN I am pretty sure this should be close to

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,

I have some trouble to deal the value of 'NaN'. For example, > exp(1e3) [1] Inf > exp(1e3)*0 [1] NaN The correct answer should be 0 rather than NaN. I will very appreciate if anyone can share some technique to get a correct answer.

Hi! In a current project, I am fitting loess models to subsets of data in order to use the loess predicitons for normalization (similar to what is done in many microarray analyses). While working on this I ran into a problem when I tried to predict from the loess models and the data contained NAs or NaNs. I tracked down the problem to the fact that predict.loess will not return a value at all

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 :

Hi- I am trying to fit a log function to my data, with the ultimate goal of finding the second derivative of the function. However, I am stalled on the first step of fitting a curve. When I use the following code: FG2.model<-(nls((CO2~log(a*Time)+b), start=setNames(coef(lm(CO2 ~ log(Time), data=FG2)), c("a", "b")),data=FG2)) I get the following error: Error in

Hi, Since C++ code compiled with g++ 4.6.3 on Windows (the version included in latest Rtools) now can produce things like '1.#IND' when writing doubles to a file (using the << operator), I wonder whether scan() shouldn't support those things. Right now (with recent R devel and latest Rtools) we get errors like: Error in scan(file, what, nmax, sep, dec, quote, skip, nlines,

I find this a bit puzzling ... > solve(matrix(c(5, 2, 3, 1), 2, 2), c(Inf, 3)) [1] NaN Inf > solve(matrix(c(5, 2, 3, 1), 2, 2)) %*% c(Inf, 3) [,1] [1,] -Inf [2,] Inf I would expect the answer to be c(-Inf, Inf), so why has the -Inf been replaced by NaN in solve? Cheers, Jonathan. --please do not edit the information below-- Version: platform = sparc-sun-solaris2.7 arch = sparc

Hello all, I posted a question to this list last week and received no response. I am unsure if this means no-one knows the answer or if I posed the question badly. I'm going to assume I posed the question badly and try again. I am new to R so it is quite likely it's a very naive question, however if there is something blindingly obvious that I am missing or if there is another resource I

Full_Name: Elizabeth Purdom Version: 1.9.1 OS: Windows Submission from: (NULL) (171.64.102.192) hist() fails if encounters 'Inf' value, rather than giving warning and removing. Other graphics, like plot(), don't have this problem. It's actually rather confusing if you are taking the log of data real valued data with a few non-positive numbers. hist() works fine in this situation

As a side note, Splus makes sin(x) NA, with a warning, for abs(x)>1.6*2^48 (about 4.51e+14) because more than half the digits are incorrect in sin(x) for such x. E.g., in R we get: > options(digits=16) > library(Rmpfr) > sin(4.6e14) [1] -0.792253849684354 > sin(mpfr(4.6e14, precBits=500)) 1 'mpfr' number of precision 500 bits [1]

Hi Everyone, I posted this a couple of weeks ago with no responses. My interface (via gmane) seemed a bit flakey at the time, so I'm venturing to repost with some additional information. I'm trying to write selfStart non-linear models for use with nls. In these models some combinations of parameter values are illegal; the function value is undefined. That's OK when calling the