similar to: Tracing gradient during optimization

Hi, I am looking for two ways to speed up my computations: 1. Is there a function that efficiently computes the 'sandwich product' of three matrices, say, ZPZ' 2. Is there a function that efficiently computes the determinant of a positive definite symmetric matrix? Thanks, S.A. [[alternative HTML version deleted]]

Hi, I have a dataframe containing a date object in the first column and numeric data in two other columns, for a total of three columns. I would like to plot the 2 numeric data columns against the dates in one window. How do I do this? It is easy to do if only one data series is to be plotted against a set of dates, but two or more datasets seems to be harder. Note: I have daily data where

Hello, I wonder why the control parameter REPORT is not supported by method SANN. Looking into optim.c I found an internal constant: #define STEPS 100 ... and decreasing this to 10 helped me fine-tuning the annealing parameters in an actual problem. Is there any reason why not passing nREPORT to samin and setting something like: STEPS = nREPORT / tmax Thomas P. -- Thomas Petzoldt

Hola colegas, por favor si me indican que estoy haciendo mal. Estoy tratando de usar el paquete QCC y colocar mas de gráfico de control en una sola ventana usando función "par" con "qcc" para presentar varios gráficos en la misma ventana. He probado pero no funciona, solo muestra un gráfico miren el código # set unequal sample sizes n <- c(rep(50,5), rep(100,5), rep(25, 5))

Can anyone help me with lbfgsb (function for optimization)? It takes the following parameters: void lbfgsb (int n, int lmm, double *x, double *lower, double *upper, int *nbd, double *Fmin, optimfn fn, optimgr gr, int *fail, void *ex, double factr, double pgtol, int *fncount, int *grcount, int maxit, char *msg, int trace, int nREPORT); What do I put for parameter ex (11th parameter)? I looked at

Hello, I get a segfault when running glmmboot in my own package glmmML. Has happened many time before, but this time I get no hint of where in my C functions the error might be. I give the output below. Can this be an R bug? I suspect it has to do with repeated calls to 'vmmin' like this: for (...){ vmax = vmaxget(); vmmin(*p, b, &Fmin, bfun,

Dear all, I have a matrix X which consists of 2 columns. I would like to convert this matrix into a list where every entry of the list consists of a single row of the matrix. Does anyone have a suggestions how to manage this? Thank you for your efforts in advance! Best, Martin [[alternative HTML version deleted]]

Hi friends, I have got a list where each element might have variable number of members. $`4213` [1] "214077_x_at" $`164832` [1] "225996_at" "235977_at" $`339010` [1] NA $`23410` [1] "221562_s_at" "221913_at" "49327_at" $`285386` [1] "229764_at" $`2099` [1] "205225_at" "211233_x_at"

> Date: Wed, 20 Mar 2002 14:31:03 +0100 (CET) > From: =?iso-8859-1?Q?G=F6ran_Brostr=F6m?= <gb at stat.umu.se> > Subject: [R] optim with gradient > > I want to maximise a function using 'optim' with a method that requires > the gradient, so I supply two functions, 'fun' for the function value > and 'd.fun' for its gradient. My question is: Since

Hello R-help   I am trying to copy and paste large column of data from windows Excel into R base speed sheet using:   Data1<-edit(data.frame())   But I can only copy and paste one cell at a time which is time consuming.   Also how can assign each column to a variable. [[alternative HTML version deleted]]

Hi all, I need to run several simple linear regressions at once, using the following data. Response variables: Bird species (sp 1, sp2, sp3...spn). Independent variable: Natprop - proportion of natural area. covarate: Effort = hours). One single linear regression would be: lmSp1 <- lm(sp1~ natprop + effort). However, I need to run this linear regression for all bird species that I have

Dear R-Listers, I am very confused with what seems to be a misuse of the faceting options with gplot function and I hope you might help me on this. z contains various simulation results from simulations with different set of parameters. I melt my data to have the following data.frame structure : > str(z) 'data.frame': 12383 obs. of 5 variables: $ vID : num 1 2 3 4 5 6 7 8

Hi, I've a data frame like this: > as.data.frame(cbind(rnorm(1:12),rnorm(1:12))) V1 V2 1 -1.30849402 -0.52094136 2 0.96157302 0.76217871 3 -0.44223351 -1.72630871 4 -0.10432438 -1.04732942 5 -1.38748914 0.95877311 6 -0.63965975 0.65494811 7 -0.24058318 0.19496830 8 -0.11172988 1.01680655 9 0.08065333 0.22168589 10 0.25196536 0.84619914 11

On Mon, 4 Nov 2019 at 14:07, David Newall <openssh at davidnewall.com> wrote: > [about scp] That's just awful, and I should have > thought it was not at all necessary. Am I missing something? > If you're saying that the scp protocol is an unfixable mess then the openssh team has been agreeing[0] with you for at least a decade and a half. We fix what we can, but some

Dear all, i am doing linear regression with robust error to know the effect of a (x) variable on (y)other if i execute the command i found positive trend. But if i check the effect of number of (x.x1,x2,x3)variables on same (y)variable then the positive effect shwon by x variable turns to negative. so plz help me in this situation. Barjesh Kochar Research scholar

Hi, I wanted to use R's lbfgsb method for minimization from C. Unfortunately, my toy examples always crashes (segmentation fault). What's wrong with it? double eval(int n, double* par, void *ex) { double result = 0; for (int i=0; i<n; ++i) { result += par[i]*par[i]; } printf("result=%.2f\n", result); return result; } void grad(int n, double *par, double *gr,

Hi, I have two datasets, x and y. Simplified x and y denote: X Y A B C A B C . . . . . . . . . . . . . . . . . . I want to implement all possible models such as lm(X$A~Y$A), lm(X$B~Y$B), lm(X$C~Y$C)... I have tried the following: fun<- function(x,y){ for(i in 1:length(colnames(x))){ for(j in 1:length(colnames(y))){

Dear R-help, I'm using the 'optim' functions to minimise functions, and have read the documentation, but I'm still not sure how to determine sensible values to use for the 'fnscale' and 'parscale' options. If I have understood everything correctly, 'fnscale' should be used to scale the objective function, so that for example if the default is

Dear R users, I am trying to figure out the control parameter in "optim," especially, "fnscale" and "parscale." In the R docu., ------------------------------------------------------ fnscale An overall scaling to be applied to the value of fn and gr during optimization. If negative, turns the problem into a maximization problem. Optimization is performed on

Hello, I've just a little problem using the function optim. Here is the function I want to optimize : test_function(x){(exp(-0.06751 + 0.25473*((x[1]-350)/150) + 0.04455*((x[2]-40)/20) + 0.09399*((x[3]-400)/100) - 0.17238*((x[4]-250)/50)- 0.45984*((x[5]-550)/150)-0.39508*((x[1]-350)/150)* ((x[1]-350)/150) - 0.05116*((x[2]-40)/20)* ((x[2]-40)/20) - 0.27735*((x[3]-400)/100)*((x[3]-400)/100) -