[R] Running Fortran code from R
Dear R users, I have a Fortran code that I would like to compile and call from R later. I have never worked with Fortran before. Does anyone know the steps to create Fortran DLLs for R on a Windows PC. Is anyone aware of a manual (or does anyone know how to) that explains: - What tools and software I need to download for that - How to set the paths in my PC - What Fortran Version is the best to have in this case - How to produce DLLs - How to load the code in R I would really appreciate it if someone can help me. Kind Regards, Amy -- The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England Wales and a charity registered in Scotland (SC 038302). [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] Regularized gamma function/ incomplete gamma function
Dear all, I would be very grateful if you could help me with: Given the regularized gamma function Reg=int_0^r (x^(k-1)e^(-x))dx/int_0^Inf (x^(k-1)e^(-x))dx ; 0rInf (which is eventually the ratio of the Incomplete gamma function by the gamma function), does anyone know of a package in R that would evaluate the derivative of the inverse of Reg with respect to k? I am aware that the function Rgamma.inv of the package Zipfr evaluates the inverse of Reg and I'm wondering wether there is a function that would evaluate the derivative of the inverse.. Alternatively, a good numerical integration package/ or simply a function that could evaluate the integral int_0^r (log(x) x^(k-1) e^(-x))dx; 0rInf would be useful. I tried the function int of the package rmutil but I'm not sure wether it is accurate especially for small values of k. Does R have a powerful numerical integration package that can deal with such functions especially when the limit close to zero in + or - Inf? Many thanks for this opportunity to post our queries, Amy The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England Wales and a charity registered in Scotland (SC 038302). [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Computational problems in R
Many thanks for your suggestions... I am still checking which one is the most useful for my simulations. Concerning using logs, this might be very helpful, but I am not sure if I can use the following: A+B = A*(1 + B/A) = exp(log(A) + log(1 + B/A)) because unfortunately B can be negative. However, I might still use logs in case (1 + B/A)0. Regards, Amy -Original Message- From: Duncan Murdoch [mailto:[EMAIL PROTECTED] Sent: Saturday, October 25, 2008 11:36 AM To: Steven McKinney Cc: A.Noufaily; r-help@r-project.org Subject: Re: [R] Computational problems in R On 24/10/2008 9:50 PM, Steven McKinney wrote: I suspect there's a deeper issue here. sum(exp(yi)) when large yi occur is problematic. exp(yi) for yi710 is just a huge number, and summing additional values only makes the overall sum larger as all components of the summation are positive. There's no way around that. Sure there is, and you quoted it below. Work on a log scale. The log of exp(yi) is yi, and it sounds as though the yi values are manageable. You might end up knowing that the log of the final answer is 2 and not be able to evaluate exp(2) in R, but you still know that the answer is exp(2). Duncan Murdoch You could try this with Robin Hankins' package brobdingnag which can handle bunches of bizarrely large numbers. What kind of process are you studying? What kind of process generates values such as exp(8/0.01) when other values are much smaller? Are these outliers in an otherwise well-behaved data set? Perhaps then they need to be set aside and investigated separately, etc. Steven McKinney Statistician Molecular Oncology and Breast Cancer Program British Columbia Cancer Research Centre email: smckinney +at+ bccrc +dot+ ca tel: 604-675-8000 x7561 BCCRC Molecular Oncology 675 West 10th Ave, Floor 4 Vancouver B.C. V5Z 1L3 Canada -Original Message- From: [EMAIL PROTECTED] on behalf of Duncan Murdoch Sent: Fri 10/24/2008 4:04 PM To: A.Noufaily Cc: r-help@r-project.org Subject: Re: [R] Computational problems in R On 24/10/2008 12:42 PM, A.Noufaily wrote: Dear all, I would be grateful if anyone can help me with the following: My aim is to compute explicitely the sum S=A+B where A=sum(exp(c_i/d)), i=1,...,n; B, c_i, and d are real numbers with -InfB,c_i+Inf; and d0. The problem is that when c_i/d 710 (for some i) R is setting exp(c_i/d) to be equal to +Inf and hence the whole summation S. So in simple cases where for example c_i=8 (for some i), and d=0.01 the whole summation is turning out to be infinite. Is there a way to get round that in R? Can anyone suggest any computational trick to calculate S when c_i/d710 (for some i)? Work on a log scale. Use the identity that A+B = A*(1 + B/A) = exp(log(A) + log(1 + B/A)) (where you chose A to be the biggest term in the sum). Duncan Murdoch Any suggestions would be much appreciated. Regards, Amy - The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England Wales and a charity registered in Scotland (SC 038302). [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. - The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England Wales and a charity registered in Scotland (SC 038302). __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] Computational problems in R
Dear all, I would be grateful if anyone can help me with the following: My aim is to compute explicitely the sum S=A+B where A=sum(exp(c_i/d)), i=1,...,n; B, c_i, and d are real numbers with -InfB,c_i+Inf; and d0. The problem is that when c_i/d 710 (for some i) R is setting exp(c_i/d) to be equal to +Inf and hence the whole summation S. So in simple cases where for example c_i=8 (for some i), and d=0.01 the whole summation is turning out to be infinite. Is there a way to get round that in R? Can anyone suggest any computational trick to calculate S when c_i/d710 (for some i)? Any suggestions would be much appreciated. Regards, Amy - The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England Wales and a charity registered in Scotland (SC 038302). [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] Error reporting in R
Hello, I am hoping someone can help me with the following: I am applying the function mle on a single data set X n times, each time using a different set of initial values v[i] (i=1,...,n). The initial values are all finite. Two cases arise: A- For some sets of initial values mle is giving parameter estimates. B- For some other initial values, mle is reporting the following error: Error in optim(start,f,method=method,hessian=TRUE,...): Initial value in vmin is not finite My aim is to tell R to return the estimates whenever case A, and to return the word Error whenever case B (using an if statement inside a loop). How to tell R to return the word Error whenever mle reports the error given above? Is there a function similar to is.nan which tests the existence of an error? Any assistance would be much appreciated, Regards, Amy - The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England Wales and a charity registered in Scotland (SC 038302). [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
