similar to: extract value from first column based on value in second column

Say I have: > set.seed( 1 ) > m <- matrix( runif(5^2), nrow=5, dimnames = list( c("A","B","C","D","E"), > c("O","P","Q","R","S") ) ) > m O P Q R S A 0.2655087 0.89838968 0.2059746 0.4976992 0.9347052 B 0.3721239 0.94467527 0.1765568

I have a list of data frames like this: a<- data.frame(x=runif(10), y = runif(10), Acc = 1) b<- data.frame(x=runif(10), y = runif(10), Acc = 0) ls<- list(a,b) and I want to remove the data frames from ls that have Acc values other than 1. How do I do that? Thanks for any help! Matthew

Hi, I want to generate a number of vectors and store them with different names, like this: x=1 while (x<100) { vector#x# = rnorm(100) x=x+1 } where each vector has, at its hand, instead of #x# a number which goes from 1 to 99. How can I do this? Thanks Gabriele Zoppoli, MD Ph.D. Fellow, Experimental and Clinical Oncology and Hematology, University of Genova, Genova, Italy Guest

Dear R-users, I state that this is for beginners, so you may ignore this in order not to be irritated. By the way, "patience" is another important thing, together with "kindness", we should keep in mind when we teach students and our own children as Jim Lemon pointed out well in the context of the Socratic method. You may know that being kind does not mean giving

hello, i have written a function to extract certain lines from a matrix. the result is a matrix with 6 cols, named dynamically according to the functions arguments. the problem is now, that i'm not able to return the resultmatrix for further use. the object is not being created. example from my console: getans(27,27) [...] [189,] 3969 161 27 1 0 1 [190,] 2142 87 27

Hi @ all, how do I get the largest or lowest k values of list? It must similar to the min() / max() function, but I just don't get it. Best wishes, Markus

Dear R Users, I have a data frame of 4 columns and ~58000 rows, the top of which looks like this: > head(max_out) Latitude Longitude Model Obs 1 -0.25 -49.25 4 4 2 -0.25 -50.25 4 5 3 -0.25 -50.75 4 4 4 -0.25 -51.25 3 11 5 -0.25 -51.75 6 4 6 -0.25 -52.25 12 5 The above shows, for each coordinate point, the

Hello R-helpers, I have the following code that works well, b <-list() for (i in 1:3){ a <- matrix(runif(1),3,3) b[[i]] <- a } b however, I need to do something similar with two loops and I was looking for something that would look like b <- list() for (i in 1:3){ for (j in 1:4){ a <- matrix(runif(1),3,3) b[[i,j]] <- a #but this doesn?t work } } Anyway, I wanted

Hi! I am trying to implement non-bipartite matching. I have around 500 sites which can be clustered by 10 regions. I am able to calculate pairwise Mahalanobis distances between sites (thanks to another post in the forum). However, I want to constrain my match to sites within the same region. Thus I want to replace elements of the distance matrix with a high value, say 999999, for sites not of the

Hi all, Given a data frame: my.df <- data.frame(a = c(1:5, 1:10, 1:20), b = runif(35)) I want to split it by "a" such that I end up with a list containing 3 components i.e. the first containing a = 1 to 5, the second a = 1 to 10 etc. In other words, sets of sequences of a. I can't seem to find the right form using the split function - can you help? Much appreciated. David

Hi Elaine I do not use it very often. I programmed it to mimic Minitab functions (partly) with some adons from czech statistics textbook written by M.Meloun (meloun militky statistics - first hit in google) Basically you can have your data in some data frame or they can be as separated vectors. The function itself expects input of 3 vectors, but you can easily to modify it for imput as

Could someone please suggest a method to store the current random seed. I'm having trouble understanding how to correctly use set.seed and .Random.seed. Specifically, I have the following code that crashes: set.seed(seed) for(i in 1:10){ print( runif(1)) } To get around this I need to split the number of iterations into chunks: set.seed(seed) for(i in 1:5){ print(runif(1))

Dear all, I would like to solve a problem similar to a multiple knapsack problem and am looking for a function in R that can help me. Specifically, my situation is as follows: I have a list of n items which I would like to allocate to m groups with fixed size. Each item has a certain profit value and this profit depends on the type of group the item is in. My problem is to allocate the items

Hi, I try to apply a function to subsets of a data.frame. tapply() does the job, but the as output, I am looking for a vector (not an array/matrix) ordered in the same way as the original data, so I can simply cbind the result to the original data.frame. Below is a minimal example. I know that there are packages that can do these things easier, but I'm looking for a fast solution not

Hi expeRts, I would like to calculate weighted mean by two factors. My code is as follows: R> tmp <- by(re$meta.sales.lkm[, c("pc", "sales")], re$meta.sales.lkm[, c("size", "yr")], function(x) weighted.mean(x[,1], x[,2])) The result is as follows: R> tmp size: micro yr: 1994 [1] 1.090

On 04/06/2016 07:58 PM, Joshua Ulrich wrote: > On Tue, Apr 5, 2016 at 9:17 PM, James Hirschorn > <james.hirschorn at hotmail.com> wrote: >> OpCl works on xts objects but not on quantmod.OHLC objects. Is this a bug? >> > Thanks for the minimal, reproducible example. > > Looks like a bug. There's no as.quantmod.OHLC.xts method, so the zoo > method is

On Fri, Apr 8, 2016 at 10:51 AM, James Hirschorn <james.hirschorn at hotmail.com> wrote: > > > On 04/06/2016 07:58 PM, Joshua Ulrich wrote: >> >> On Tue, Apr 5, 2016 at 9:17 PM, James Hirschorn >> <james.hirschorn at hotmail.com> wrote: >>> >>> OpCl works on xts objects but not on quantmod.OHLC objects. Is this a >>> bug?

V; Sent via BlackBerry from T-Mobile -----Original Message----- From: r-help-request at r-project.org Date: Tue, 30 Sep 2008 12:00:06 To: <r-help at r-project.org> Subject: R-help Digest, Vol 67, Issue 31 Send R-help mailing list submissions to r-help at r-project.org To subscribe or unsubscribe via the World Wide Web, visit https://stat.ethz.ch/mailman/listinfo/r-help or, via email,