similar to: Please help with min()

The documentation says, "pmax and pmin take several vectors as arguments and return a single vector giving the parallel maxima (or minima) of the vectors." I discovered that, if you use a matrix or array instead of a vector, pmax returns a matrix or array, respectively. This makes pmax and pmin much more useful, and should not be left to people to discover on their own! For example:

Hi, I wonder whether similarly to the very quick rowSums and colSums functions in the base package, one could add quick functions that calculate the min or max over rows / cols in a matrix. While apply(x,1,min) works, I found out by profiling a program of mine that it is rather slow for matrices with a very large number of rows. A quick functionality seems to be already there in the

Dear Mailing List Members, the problem I've been grappling with für quite some time now is the following: I have a 100 rows x 200 columns matrix. data.set <- matrix(rnorm(20000, 100, 200)) Now I would like to get a vector of length 100 which collects the values from the following procedure: Take the sum of the minima of the two values from each row of columns 1 and 101, and divide it

Hi Is there a function which determines the location, i.e., index of the all minimums or maximums of a numeric vector. Which.min(x) only finds the (first) of such. > x <- c(1:4,0:5, 4, 11) > x [1] 1 2 3 4 0 1 2 3 4 5 4 11 > which.min(x) [1] 5 > which.max(x) [1] 11 > but I need which.min(x) to be 5 11 which.max(x) to be 4 10

Full_Name: Maura Monville Version: 2.8 OS: Mac OS/X 10.5 Submission from: (NULL) (87.4.122.234) Here is the code that causes wavCWTPeaks error aats <- create.signalSeries(aa, pos=list(from=0.0, by=0.033)) aa.cwt <- wavCWT(aats) x11 (width=10,height=12) plot (aats,main=paste(insig," Cycle: ",j,sep="")) aa.maxtree <- wavCWTTree (aa.cwt,

I am using numerical optimization to fit a 1 parameter model, in which the input parameter is bounded. I am currently using optimize(), however, the problem turns out to have local minima, and optimize does not always seem to find the global minimum. I could to write a wrapping function that tries multiple intervals or starting values, but I would prefer a package that has built-in methods to make

I have data in the form of (x,y) pairs and would like to find local minima and maxima (typically the zeros of the 2nd derivative) of the y values. I looked at numericDeriv, but I don't have an "expression" per se. I looked at optim, also, but it looks like it will find only one "global" max or min. I can code up my own piecewise derivatives, but wondered if there is

I have water chemistry data with censored values (i.e., those less than reporting levels) in a data frame with a narrow (i.e., database table) format. The structure is: $ site : Factor w/ 64 levels "D-1","D-2","D-3",..: 1 1 1 1 1 1 1 1 ... $ sampdate: Date, format: "2007-12-12" "2007-12-12" ... $ preeq0 : logi TRUE TRUE TRUE TRUE TRUE

Dear R-helpers ? I have 7 data points that I want to fit a continuous curve to, that should look similar to a sine wave My data points would mark the local minima and maxima respectively. This is what I?ve got so far. And I would keep doing so, but sadly nls() then says that it has reached the maximum number of Iterations? ?

Good morning once more. My problem of yesterday has been addressed. Having learned a few tricks from that, I wish to ask another question in connection with that. My data is a cosmic ray data consisting of dates and counts. When I plot a graph of counts versus dates, the resultant signal shows a number of maximum and minimum points. These minimum points (turning points) are of interest to me.

> On 26 Aug 2017, at 16:39, niharika singhal <niharikasinghal1990 at gmail.com> wrote: > > Hi, > > Thanks for your mail, and time > > It is not working for some arguments, when mean value is like >6. > > > case > > mc0 <- c(0.08844446,0.1744455,0.1379778,0.1209769,0.1573065,0. > 1134463,0.2074027) > > rv

Dear all, I wonder which R algorithm could perform a search of local maxima in an spatial grid, in other words, having the coordinates of a map (x,y,z... up to 6 coordinates) and then the altitude/height at each point (h) (in total 7 numerical variables) I would like to localise the peaks (local maxima) of that topological surface. Which R algorithm can perform this? Thanks a lot, Josep Maria,

Hi, Thanks for your mail, and time It is not working for some arguments, when mean value is like >6. case mc0 <- c(0.08844446,0.1744455,0.1379778,0.1209769,0.1573065,0. 1134463,0.2074027) rv <-UnivarMixingDistribution(Norm(486.4255, 53.24133), Norm(664.0713, 3.674773), Norm(669.0484, 4.101381),

Hello, all, I have a dataframe of three rows and umpteen columns. I want to show the maximum, minimum, and median with a vertical line and a central dot (I'd use a boxplot, but with only three data points, that's overkill; I can't just use points, because of overlap and some of the other data plotted on the graph). This works: > boxplot(data_frame,

Hello I have data in many files in a directory, how can I loop through the files in a given dir in-order-to build a data.frame? thanks

Dear R helpers, I would like to write a loop that makes 4 objects (called A, B, C, and D) each of which contains ten random numbers. This attempt: individuals<-c("A","B","C","D") for(i in 1:length(individuals)) { individuals[i]<-rnorm(10) } does not work because "individuals[i]" is not the proper way to extract each letter from the

Hi, I'm a new user. I've been reading through the manual and looking at various examples but am still trying to make sense of the most efficient ways to handle matrices of data. If I have a 2D matrix of data, how do I get the mean, min, max value of each row? I see the "mean" function on a matrix will give me averages by row, but min and max give me the value for the entire

Dear all, I have 3 matrices with the same dimension, A,B,C and I would like to produce a matrix D where in each position would retrieve the max(or min) value along A,B,C taken from the same position. I guess that apply functions should fit, but for matrices objects I am not getting it. thanks in advance, Diogo André Alagador [[alternative HTML version deleted]]

I was surprised this morning, that it seems as though the min() function does not work as *I* anticipated when given vector arguments. For example: a <- 1:10 b <- c(rep(1, times=5), rep(10, times=5)) Result: > min(a,b) 1 What I actually wanted was a term by term minimum, i.e.: ifelse(a<=b, a, b) 1 1 1 1 1 6 7 8 9 10 Am I losing much in terms of computation power if I use

I have two variables in a data frame, I want to generate two additional variables. For every observations (i.e. every row), I want the first new variable 'min' to carry the minimum of the two existing variables, and I want the second new variable 'max' to carry the maximum of the two existing variables. I then want to sort the data frame by min and max, and delete duplicated rows