similar to: Lattice - parallel: xlim and adding lines

deaRs, I want to build a covariance matrix out of the data from a binary file, that I can read in chunk by chunk, with each chunk containing a single observation vector X. I wonder how to do that most efficiently, avoiding the calculation of the full symmetric matrices XX'. The trivial non-optimal approach boils down to something like: Q <- matrix(rnorm(100000),ncol=200) M <-

This is some interesting: > -8^(1/3) [1] -2 > x=(-8:8) > y=x^(1/3) > y [1] NaN NaN NaN NaN NaN NaN NaN NaN 0.000000 1.000000 [11] 1.259921 1.442250 1.587401 1.709976 1.817121 1.912931 2.000000 So, can anybody explain this?! (Why is x[1]^(1/3)=y[1]=NaN, but -8^(1/3)=-2?) Thx!!! [[alternative HTML version deleted]]

I am pretty new to R. So this may be an easy question for most of you. ? I would like to calculate the squared distances of a large set (let's say 20000) of vectors (let's say dimension of 5) to a fixed vector. ? Say I have a data frame MY_VECTORS with 20000 rows and 5 columns, and one 5x1 vector y. I would like to efficiently calculate the squared distances?between each of the 20000

Hi, I am trying to plot several columns in different graphs in columns and rows. The first column of my data file is the time, and the third is the 'elevation angle' with 19 different numbers. I would like to plot the rest of the columns with the x axis as time and the individual angles in different colours. Here is the code I am using right now. It plots the different columns with time,

I'm trying to create a graph where different cells of a grid (a shapefile) will be painted with a color share scale, where the most easy way is to use gray(). Can I somehow get a vector (gradient) of colors, a vector of colors with other methods but gray()? I'm doing this until now quad_N_sp <-

Dear all, I have a large matrix with about 2500 variables, and 100 rows. I would like to calculate the means of the every 10 variables starting from 1:2500 and saving the results as a vector or matrix. How can I do that? Alternatively, How can I create 250 subset matrices in the order of variables 1:2500 in groups of 10 from the single matrix which had initially 2500 variables ? I guess I have

Hello R-helpers, I am trying to search for string that includes the caret symbol, using the following code: grepl("latitude^2",temp) And R doesn't like that. It gives me: > temp<-c("latitude^2","latitude and latitude^2","longitude^2","longitude and longitude^2") > temp [1] "latitude^2" "latitude and

Dear R-users, I would like to apply a function (more precisely sd()) over the third dimension of a three-dimension array. The function apply would be interesting but the chosen function can only be applied on the rows and columns of the array according to the help file. I can use a loop to cut the array in matrices and then use apply for each replication, but it's not very nice. A small

Hello, I am a newcomer to R and therefore apologize for posting such a basic question. I am trying to multiply 2 matrices t(X1)%*%X1, where t(X1) is: 1 2 3 4 5 8 12 13 20 24 26 27 31 33 34 36 37 40 41 42 45 46 47 48 49 ones 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Shadow 0 1 1 1 1 1 1 1 0 1 1 1 1 0 1 0

Hello! I'm trying to build a lower triangular matrix (with zeros in the diagonal) from a particular dataframe. The matrix I have to construct has 203 rows and 203 columns and that makes 20503 values to be included within (that's why I can't do it manually). To illustrate the dataframe I have, I'll give you an example of a dataframe and matrix with dimensions 6x6 (to make it

Dear all, I admit this is not anything to do R and even with Statistics perhaps. Strictly speaking this is a math related question. However I have some reasonable feeling that experts here would come up with some elegant suggestion to my question. Here my question is: What is sum of all Integers? I somewhere heard that it is Zero as positive and negative integers will just cancel each other out.

Hi :) Was just wondering whether someone could help me with adjustments to trellis plots (parallel). I've got two way multivariate data. I want to make parallel plots for one of the factors, and want to color the lines according to the other factor. The first thing I manage, but with the other I'm lost :( Can only change the overall color. This is basically how far I get:

Dear R experts, How to find out the index of minimum or maxmum number in a vetor or data.frame? For example, a= n price 1 50 -2 100 0 200 -1 300 ...... I want to find out the row which the n is the smallest or largestest and extract the price. Thanks Ted -- View this message in context:

I've been wondering what L means in the R computing context, and was wondering if someone could point me to a reference where I could read about it, or tell me what it's called so that I can search for it myself. (L by itself is a little too general for a search term). I encounter it in strange places, most recently in the "save" documentation. save(..., list = character(0L),

Hi. Please, how can I put together 2 or more lines at the same scatterplot ? Example: measures of protein intake (quantitative) of 4 children over 30 days, by day. How to plot all children at same graphic: Protein X Time ? Is there any command like "overlay" ? Thank you, Mauricio

Hello everyone, I would like to parse very large xml files from MS/MS experiments and create R objects from their content. (By very large, I mean going up to 5-10Gb, although I am using a 'small' 40M file to test my code.) My first attempt at parsing the 40M file, using the XML package, took more than 2200 seconds and left me quite disappointed. I managed to cut that down to around 40

Hello to all again :) Again, I have an issue with my homework. I was troubling myself for two days, and I still can't get it :( So, if someone can help me, I would be so grateful... HOMEWORK 1. I need to draw function, random walk take the length of walk, and its in 2D. As a result, I have to take matrix in which are i-lines of matrix, written coordinates on i-steps radnom.walk <-

for the script, please kindly see the script below. At line 10 and line 13, my problems occurs. The first one is I try to retrieve the gene official name from a column of a table. The pattern of official name is something starting with gene_name. For detail problems, please see the according lines. Any suggestions are appreciated example of matching source (extract the Nnat, sometime it would

Hi, I have the following data file to be parsed and captured as a data frame: __DATA__ #GDS_ID GENE_NAME GENE_DESCRIPTION GENE_FUNCTION 1007_s_at | DDR1 | discoidin domain receptor tyrosine kinase 1 | protein-coding 1053_at | RFC2 | replication factor C (activator 1) 2, 40kDa | protein-coding 117_at | HSPA6 | heat shock 70kDa protein 6 (HSP70B') | protein-coding __END__ In particular it is

Dear R-developers, I came to a somewhat unexpected behaviour of read.csv() which is trivial but worthwhile to note -- my data involves a protein named "1433E" but to save space I drop the quote so it becomes, Gene,SNP,prot,log10p YWHAE,13:62129097_C_T,1433E,7.35 YWHAE,4:72617557_T_TA,1433E,7.73 Both read.cv() and readr::read_csv() consider prot(ein) name as (possibly confused by