similar to: Power functions?

Why does the expression "(-8)^(1/3)" return NaN, instead of -2? This is not answered by http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-are-powers-of-negative-numbers-wrong_003f Thanks, Dave [[alternative HTML version deleted]]

Dear R developers, is that right? > -27^(1/3) [1] -3 > c(-27,27)^(1/3) [1] NaN 3 i'm using sign( c(-27,27) ) * abs( c(-27,27)) ^(1/3) , thanks [[alternative HTML version deleted]]

please excuse me if this ones a basic error > y<-c(-0.7,-0.6,-0.5) > -0.7^1.22 [1] -0.6471718 > y^1.22 [1] NaN NaN NaN am I missing something important in my basic math?

Hi why I can't do this? m<-c(1,-2,3) m^2.1 with a negative number in it ,but I can do this to a single negative number like -2^2.1~ Thank you ~ JIngsi [[alternative HTML version deleted]]

Can someone please enlighten me as to why the following happens? > -2.7^8.6 [1] -5125.407 > p<- -2.7 > q<- 8.6 > p^q [1] NaN R seems perfectly able to calculate -2.7^8.6, but fails when the exact same values are assigned to variables and then the computation is repeated. Thanks in advance for any suggetsions. Kris.

I noticed that the text() command adds text to a plot. Is there a way to either make the plot blank or add text to a "blank sheet". I would like to "plot" a page that contains just text, no plot lines, labels, etc. Suggestions? Kevin [[alternative HTML version deleted]]

This is definitely a newbie question but from the documentation I have not been able to figure out what the partial sort option on the sort method does. I have read and re-read the documentation and looked at the examples but for some reason it doesn't register. Would someone attempt to explain what sort with a non-null partial array of indices does? Thank you. Kevin

Am Dienstag, 23. April 2013, 22:50:51 schrieben Sie: > [...] > Giving more-than-expected precision can be just as bad for the user as less. > It tends to come up in situations where the optimization would break some > symmetry, the same way that aggressively forming FMAs can break user code. > [...] > > It boils down to the fact that giving excess precision in >

Given a Date object or simply a year is there an R function to tell me if the it is a leap year or not? I was hoping for something like 'is.leapyear'. I probably can build my own function (year divisible by 4 etc.) but I would rather use an existing function if it is available. Thank you. Kevin

Why does: (shape/scale) * (1:365/scale)^(shape - 1) return a vector of numbers but calling a function hasard(1:365,shape,scale) defined like: hazard <- function(x,shape,scale) { return (shape/scale) * (x/scale)^(shape - 1) } Only return a single value? It is like x becomes a single value passed as an argument. Thank you. Kevin

This is a very simple question but I couldn't form a site search quesry that would return a reasonable result set. Say I have a vector: x <- c(0,2,3,4,5,-1,-2) I want to replace all of the values in 'x' with the log of x. Naturally this runs into problems since some of the values are negative or zero. So how can I replace all of the positive elements of x with the log(x) and the

I noticed that when I fit a linear model using 'lm' there is an attribute called "factors" that is added to the "term". It doesn't seem to appear for 'model.matrix', just 'lm'. I have been unable to find where it gets constructed or what it means? It looks like a two dimensional array that I may be able to use so I would just like to get some

I am trying to upgrade to R 2.14 from R 2.13.1 I have compied all the libraries from the 'library' directory in my existing installation (2.13.1) to the installed R 2.14. Now I want to uninstall the old installation (R 2.13.1) and I get the error: Internal Error: Cannot find utCompiledCode record for this version of the uninstaller. Any ideas? Kevin [[alternative HTML

The transformation in LibCallSimplifier::replacePowWithSqrt with respect to -Inf uses a select instruction, which based on the observed behaviour, incorporates the side effects of the unchosen branch. This means that (for pow) a call to sqrt(-Inf) is materialized. Such a call is specified as having a domain error (C17 subclause 7.12.7.5) since the operand is less than zero. Contrast this with

I am running R 2.9.2 and creating a PDF that I am trying to open with Adobe Reader 9.2 but when I try to open it the reader responds with "There was an error opening this document. The file is damaged and cannot be repaired.: I am using the R command(s): pdf(file="cat.pdf", title="Historical Sales By Category") for(j in 1:length(master)) { d <-

> On Jan 12, 2017, at 2:21 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > > >> On Jan 12, 2017, at 11:04 AM, Steve (Numerics) Canon <scanon at apple.com <mailto:scanon at apple.com>> wrote: >> >>> >>> On Jan 12, 2017, at 12:58 PM, Friedman, Eli via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>>

Hi, It looks like SimplifyLibCalls has a tendency to emit calls to libm functions without checking with TLI whether these calls are available. For example, PowOpt has this code: struct PowOpt : public UnsafeFPLibCallOptimization { PowOpt(bool UnsafeFPShrink) : UnsafeFPLibCallOptimization(UnsafeFPShrink) {} virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)

On Mon, Sep 14, 2020 at 12:45 PM Sanjay Patel <spatel at rotateright.com> wrote: > Yes, that looks like a bug. The transform is ok in general for negative > numbers, but -Inf is a special-case for pow(), right? > If so, we probably need an extra check of the input with > "isKnownNeverInfinity()". > There is an extra check there already, but it uses

This may be a begining question. If so, please bear with me. If I have some data that based on the historgram and other plots it "looks" like a beta distribution. Is there a function or functions within R to help me determine the model parameters for such a distirbution? Similarily for other "common" distirbutions, Poisson(lambda), Chi-Square(degrees of freedom, chi-square

I give up. Maybe it is my search (Windows) but I cannot seem to find the definition of the F77_CALL or F77_NAME macros. Either there are too many matches or the search just doesn't find it. For example where is the source for: F77_CALL(dpotri) ? Thank you. Kevin