search for: fmins

Hi, I’d like to re-propose adding intrinsics for fmin / fmax. These can be used to implement the equivalent libm functions as defined in C99 and OpenCL, which R600 and AArch64 at least have instructions with the same semantics. This is not equivalent to a simple fcmp + select due to its handling of NaNs. This has been proposed before, but never delivered

… actually, now that I’m able double-check this, I’m quite surprised to find that we didn’t define fmax(+0,–0) in IEEE–754, which says [paraphrased]: minNum(x,y) is x if x < y, y if y < x, and the number if one is a number and the other is NaN. Otherwise, it is either x or y (this means results might differ among implementations). So I think your proposed semantics are perfectly

This is a problem with all floating point folding, not just with these operations. What Matt is proposing is consistent with how we fold other libm intrinsics. —Owen > On Aug 18, 2014, at 1:22 AM, Mueller-Roemer, Johannes Sebastian <Johannes.Sebastian.Mueller-Roemer at igd.fraunhofer.de> wrote: > > Wouldn’t it be better to use the target’s implementation (if there is one)

Hi Carter, I would strongly advise you against this direction. I’m aware of two directions that existing languages go in defining min/max operations: - IEEE 754, C, Fortran, Matlab, OpenCL, and HLSL all define it not to propagate NaNs - C++ (std::min/std::max) and OpenGL define it in the trinary operator manner: (a < b) ? a : b What you’re proposing does not match any existing languages

Hi, Is there something like the Matlab function FMINS in any R packages? Here is the help file of fmins in case something similar exist under R with a different name. Thanks in advance. Yves Gauvreau *********************** function [x, options] = fmins(funfcn,x,options,grad,varargin) %FMINS Minimize function of several variables. % X = FMINS(&...

I was trying to find source for optimize and I ran across function (f, interval, ..., lower = min(interval), upper = max(interval), maximum = FALSE, tol = .Machine$double.eps^0.25) { if (maximum) { val <- .Internal(fmin(function(arg) -f(arg, ...), lower, upper, tol)) list(maximum = val, objective = f(val, ...)) } else { val <-

Hi, The specification for the llvm.minnum/llvm.maxnum intrinsics is too unclear right now to usefully optimize. There are two problems. First the expected behavior for signaling NaNs needs to be clarified. Second, whether the returned value is expected to be canonicalized (as if by llvm.canonicalize). Currently according to the LangRef: Follows the IEEE-754 semantics for minNum, which also

On Sep 15, 2014, at 4:17 PM, Owen Anderson <resistor at mac.com> wrote: > I’d be fine with that proposal. I could even be convinced if we wanted to add a pair of NaN-propagating intrinsics as well, for targets and languages that want those semantics, even if I disagree with them. I do think that, if we are using the minnum/maxnum names, we should explicitly note that they are

Hi, To make a calculation (an innermost loop) that uses optimize faster, I think I should write things in C. Is it possible to call fmin, which is called by optimize, from C? It is not listed in Writing R extensions, but I found double Brent_fmin(double ax, double bx, double (*f)(double, void *), void *info, double tol); in Applic.h. Is this the function I am looking for?

Given IEEE-754's sway, and its saying what it does on this point, but given also the popularity of NaN-propagating min and max, how about a compromise? We add intrinsics following the IEEE-754 semantics, but we also follow IEEE-754 (and ARMv8) in renaming them to minnum and maxnum, to clarify which interpretation these intrinsics are using. -------------- next part -------------- An HTML

> On Sep 12, 2014, at 10:27 AM, Dan Gohman <dan433584 at gmail.com> wrote: > > > More generally, I don’t see a compelling reason for LLVM to add intrinsic support for the version you’re proposing. Your choice can easily be expanded into IR, and does not have the wide hardware support (particularly in GPUs) that the IEEE version does. > > The IEEE version can also be

Hi list! I'm getting an error message when trying to fit an accelerated failure time parametric model using the aftreg() function from package eha: > Error in optim(beta, Fmin, method = "BFGS", control = list(trace = > as.integer(printlevel)), : > non-finite finite-difference value [2] This only happens when adding four specific covariates at the same time in the

On Fri, Sep 12, 2014 at 3:04 PM, Owen Anderson <resistor at mac.com> wrote: > > On Sep 12, 2014, at 2:24 PM, Owen Anderson <resistor at mac.com> wrote: > > > On Sep 12, 2014, at 10:27 AM, Dan Gohman <dan433584 at gmail.com> wrote: > > >> More generally, I don’t see a compelling reason for LLVM to add intrinsic >> support for the version you’re

> On Jul 23, 2018, at 3:40 PM, Alex Bradbury via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > On 23 July 2018 at 11:56, Arsenault, Matthew via llvm-dev > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > >> Hi, >> >> >> The specification for the llvm.minnum/llvm.maxnum intrinsics is too unclear >> right

Hi, I'm getting an error message using polr(): Error in optim(start, fmin, gmin, method = "BFGS", hessian = Hess, ...) : initial value in 'vmmin' is not finite The outcome variable is ordinal and factored, and the independant variable is continuous. I've checked the source code for both polr() and optim() and can't find any variable called

Hi all, I would like to set up an iterative read & write sequence to avoid reading and writing each file one at a time. Hundreds of data sets to re-calculate.? The code I have works well individually, but would like to set up an iterative read, calculate and write changing the input and output file names each iteration. I? think I have read that there is an R? feature using

Dear R Users/Experts, I am using a function called logitreg() originally described in MASS (the book 4th Ed.) by Venebles & Ripley, p445. I used the code as provided but made couple of changes to run a 'constrained' logistic regression, I set the method = "L-BFGS-B", set lower/upper values for the variables. Here is the function, logitregVR <- function(x, y, wt =

I have been working on a patch to add support for max/min reductions in LoopVectorize. One of the comments that came up in review is that the implementation could be simplified (and less fragile) if max and min intrinsics were recognized rather than looking for compare-select sequences. The suggestion was to change compare-selects into max and min intrinsic calls during instcombine. The

Hi, I have read R's Writing Extensions manual and am still confused about how to use some of the routines there when I call from C. Specifically, I am writing a little test function which I will optimize using the nmmin function which underlies R's optim() with Nelder-Mead. I guess I wonder what library/header files I should be using. I was using R_ext/Applic.h and linking with libR but I

Sorry, I deleted my old post. Pasting the new query below. Dear R Users/Experts, I am using a function called logitreg() originally described in MASS (the book 4th Ed.) by Venebles & Ripley, p445. I used the code as provided but made couple of changes to run a 'constrained' logistic regression, I set the method = "L-BFGS-B", set lower/upper values for the variables. Here