search for: logarithmic

Hello, in scilab /Matlab there are functions that can create linear sequences (like R's seq()) as well as logarithmic sequences. Is there a logarithmic aequivalent of seq()? Or maybe this would be an idea for newer R-releases, maybe a type-option with "linear" and "logarithmic" as parameters....?! Ciao, Oliver

Hello I want to calculate natural logarithm of sum of combinations as follow: (R code) { com_sum=choose(2000000,482)*choose(1000000,118)+choose(2000000,483)*choose(1000000,117)+...+choose(2000000,i)*choose(1000000,600-i)+...+choose(2000000,600)*choose(1000000,0) #calculate the sum result=log(com_sum) #calculate the log of the sum } But

Hi, In order to use the mle2-function, one has to define the likelihood function itself. As we know, the likelihood function is a sum of the logarithm of probability density functions (pdf). I have implemented myself the pdfs that I am using. My problem is, that the pdfs values are negative and I cann't take the logarithm of them in the log-likelihood function. So how can one take the

Hi, I have some questions for the wireframe function of the lattice package. My dataset's "x-data" are sampled logarithmically and as such I would like to have a semilogarithmic 3D plot when plotting a time series. Does anyone know how to change the example in http://addictedtor.free.fr/graphiques/sources/source_40.R such that x or y would be logarithmically scaled? Also, I would like to change the color scale such th...

Dear Researches, sorry for the easy and common question. I am trying to justify the idea of RandomForest don't require a transformations (e.g. logarithmic) of variables, comparing this non parametrics method with e.g. the linear regressions. In leteruature to study my phenomena i need to apply a logarithmic trasformation to describe my model, but i found RF don't required this approach. Some people could suggest me text or bibliography to study?...

...logaritmic y-axis with the base of e. When I type "log="y"", the axis transforms into a logaritmic axis with the base of 10. Best regards, Elisabeth > Dear Elisabeth, > > I'm not sure if I have understood your question -- are you trying > to use a different logarithmic base? > > Kind regards, > > Xianwen > > On Sun, May 9, 2010 at 8:05 PM, Elisabeth Bjerke Rastad > <ebr024 at post.uit.no> wrote: >> Hello! >> >...

Dear R-help, Here's a simple example of nonlinear curve fitting where nls seems to get the answer wrong on a very simple exponential fit (my R version 2.7.2). Look at this code below for a very basic curve fit using nls to fit to (a) a logarithmic and (b) an exponential curve. I did the fits using self-start functions and I compared the results with a more simple fit using a straight lm() command. The logarithmic fit works 100% correctly below. The problem is with the exponential fit: the nls command gives the wrong values and I have comple...

How can perform logarithmic binning in the scatterplot? I could only take the log of the variables and plot them, but I am sure that is not the way. I have a very huge data, and would want to plot those high density scatterplots and code then with different colors for the bins/density. -- View this message in context: http:/...

...ake a (more or less) 2-d histogram, and for the most part it's working fine with my data. However, I can't get the color key to do what I need. I can give it labels and custom cutoffs, but my cutoff lines (and hence my labels) aren't evenly spaced, instead they're more-or-less logarithmic, starting at [0,20,50,100...] and continuing on up to 5 million. Levelplot scales the ticks/labels linearly on the color key, leaving most my labels scrunched down atop each other at the bottom and only the last few (..."500K","1M","2M","5M") really visib...

...de: library(vioplot) x1 <- GSMrxDL x2 <- WIFI x3 <- UMT vioplot(x1, x2, x3, ylim=c(0, 10), names=c("GSMrxDL", "WIFI", "UMT"), col="gold") title("NIS Strahlung", xlab="Sender", ylab="V/m") Now I want to scale the y-axis logarithmically, i.e. 0.01; 0.1; 1; 10. How can I do this? Thank you very much Alex --

Hi, In continuation of the discussion of melange comments,about negative value returned in matcher due to logarithm of probabilities. *I**f we make K suitably large, we could clamp each log(K.Pi) to be >= 0, and this change will only affect really low probability terms (those with Pi < 1/K, so you can adjust K to suit):* *W' = sum(i=1,...,n, max(log(K.Pi), 0))* Did you mean for low

This should be simple but I am struggling. I like to easily switch in xyplot between a linear or logarithmic y-axis by setting a logical flag logY to False or True. This switch changes the scales argument of xyplot. I found out that the original two-dimentional data (Conc vs Time in my case) are converted to log10(Conc) if log=TRUE in scales, but it appears that functions like panel.curve need to provide...

...around with the Ajax.PeriodicalUpdater. In looking at the API, I''m liking the decay option -- not necessarily for my current purpose, but just to keep in mind -- and I have a question: can the decay be a function which returns an integer? Basically, why I''m looking for is a logarithmic decay (where the system updates a lot right after a change but then slows down the frequency of updates but not to be slower than the horizontal asymptote of the logarithm used). Using a function to produce a logarithmic series of integers wouldn''t be a problem, but can that function...

Hi there, I guess this must be a standard issue, but I'm starting to go crazy with it. I simply want a plot with the x axis being logarithmic, having labels 1, 10, 100..., and ten unlabelled ticks between each of them - just as they introduce logarithmic axis at school. I've played around a bit with log="x", xlog=T (where exactly is the difference here?), xaxp, and xaxt (unfortunately xaxt="l" isn't implem...

Hi, I am quite new to R and I have two questions regarding ROCR. 1. I have tried to understand how to extract area-under-curve value by looking at the ROCR document and googling. Still I am not sure if I am doing the right thing. Here is my code, is "auc1" the auc value? " pred1 <- prediction(resp1,label1) perf1 <- performance(pred1,"tpr","fpr") plot(

Hi! I'm using a large panel data, and now I have faced some difficulties with my analysis. The predictors are not normally distributed and there are quite many outliers (some of them are influential though). I have tried to change the logarythm, but i'm not sure, how to do that. I want also draw a plot picture in which logarythms of predictors x and y are changed. How could I do that?

Hi everyone, I am new in R, just used it for 2 weeks and I have a basic question. I have data, for example table$attrib that I would like to plot its cumulative distribution in logarithmic scale. How do I do that? After browsing internet, I tested this command: > plot.ecdf(1:100, log ="y", table$attrib) I got a plot, but I am not really sure what 1:100 and log="y"did to produce the plot. Any help is appreciated. Thank you, Zuki

> My question is not about statistics but more obviously about an R command. > I would like to plot an histogram with a logarithmic scale. I have > searched through R documentation and have read about the "log" option. > What matters is that it does not work with the hist() function. I'm > working with R version 1.2.3 . Maybe the problem has been solved in R 1.3 > . > Thanks for your help, > Rega...

Dear R-helpers! Using logarithmic axes sometimes results in an odd labelling. In some cases, only half of the axes do have labels. Hmmmm. I've played around with par(lab=c(5,5,7)) but that didn't help. An example: ---- begin example ---- x <- c(0.12, 0.3, 0.53, 1.1, 1.8, 2.6, 4.5) y <- c(0.012, 0.021, 0.03...

...orm(1000), freq=FALSE, seq(-4, 4, .5), ylim=c(0.001, 0.5), log="y") Which gives the expected histogram but also warnings for my log="y" command (""log" is not a graphical parameter in: axis(side, at, labels, tick, line, pos, outer, font, lty, lwd, ") and no logarithmic y-axis. Any ideas how to achieve that, I couldn't find anything? Best regards David *************************************************************** Dr. David Bolius Agroscope Reckenholz-T?nikon ART Gruppe Lufthygiene/Klima Reckenholzstrasse 191, CH-8046 Z?rich Tel. ++41 (0)44 / 377 75 1...