similar to: performing operations on a dataframe

Displaying 20 results from an estimated 200 matches similar to: "performing operations on a dataframe"

2009 Nov 06
1
using xyplot to plot frequencies
Hi all, First off, thank you for the overwhelming response last time. I'm still trying to figure out the syntax of R to plot some distributions of some frequencies. I've managed to plot histograms from the data, but I would like to clean it up using xyplot from library(lattice). Unfortunately I cannot find a solution to my problem. Given a dataframe "all2", with numerical
2009 Oct 26
1
zeros keep dropping
Hello All! I am trying to plot the frequency of species coocurrance. If given a data set similar like this...(V1="species A", V2="species B", V3="frequency of cooccurance") > data V1 V2 V3 1 A B 0 2 A C 2 3 A D 5 4 B C 0 5 B D 1 6 C D 0 > data1<-as.data.frame(lapply(data,function(x)(rep(x,data$V3)))) > as.data.frame(data1[-1]) >
2004 Nov 11
6
scan or source a text file into a list
I've ported somebody else's rather cumbersome Matlab model to R for colleagues that want a free build of the model with the same type of I/O. The Matlab model reads a text file with the initial parameters specified as: C:\Data\Carluc\Rport>more Params.R # Number of years to simulate nYears = 50; # Initial year for graphing purposes year0 = 1970; # NPP/GPP ratio (cpp0 unitless) fnr =
2010 May 04
2
R for web browser
Hi Everyone, Does anyone know of any projects for running an interactive R session within a web browser? I'm looking for something similar to the one on the Ruby website (http://tryruby.org), except for R. Thanks for your responses in advance! Lanna ----- Lanna Jin lannajin at gmail.com 510-898-8525 -- View this message in context:
2010 Mar 10
2
function to create multiple matrices
Hi All, If given a dataframe (long form) with Year, Species, and Location, How would I write a function that would create a unique matrix of Species & Location for each Year? What I've tried doing is the following: data #dataframe dataT<-table(data$Species,data$Location,data$Year) #creates tables of Species vs Location for each Year But I'm encountering issues individually
2011 Nov 07
2
adjusting levelplot color scale to data
Hi guys, I have a matrix with values varying from approximately -0.7 to 0.33 that I want to create a heatmap/levelplot with. When I execute the levelplot function for my matrix, I end up getting colors that are adjusted to the max and min rather than around 0. In other words, ideally I would like to have a color ramp that goes from red (negative number), to white (0), to blue (positive);
2010 Mar 16
1
nested looping functions and dataframes
Hey All, So, I am confused how exactly to use nesting loop functions in R to spit out data frames. I've managed to create a working function for my data set that generates a data frame for a given set of Year i and Location j; but how would I do it for all Years and Locations? Here is my working function: test<-function(i,j){ a<-x[which(x$Year==i & x$Location==j),]
2010 May 04
7
How to replace all <NA> values in a data.frame with another ( not 0) value
I need to replace <NA> occurrences in multiple columns in a data.frame with "000/000" how do I achieve this? Thanks Nevil Amos
2002 Apr 06
1
read.table and trouble
Hi all, I'm porting a library I wrote in S-plus over to R. All but one of the functions work fine. The only one that doesn't is really giving me a headache. I'm admitting defeat. Can anybody help? Object example3 has been read in using read.table. The statement works fine in S-Plus. When I run the same statement in R the column Prefix, which is read in using the as.character
2012 Mar 29
1
Retrieving matrix column and row names by index value
Hi all, So let's say I have a matrix, mdat and I only know the index number. How do I retrieve the column and row names? For example, > mdat <- matrix(c(1,2,3, 11,12,13), nrow = 2, ncol=3, byrow=TRUE, dimnames = list(c("row1", "row2"), c("C.1", "C.2", "C.3"))) > mdat[4] [1] 12 >
2010 May 03
8
Delete rows with duplicate field...
as a r noob i am having another problem: i have a big dataframe where each row corresponds to one entry and each column is a field... for instance, i have the column ID and time and many more... Id like to get a dataframe where all IDs are just included once (some users with that ID might have several entries but Id like to kepp only one).. when i use unique I only get a list of the levels (or
2001 Dec 13
2
k-means with euclidian distance but no coordinates
Hi, I'm trying to build a thesaurus that will sensible values for rare words. I suspect the best algorithm to use is k-means although I'm not sure about that -- I would have preferred a k dimensional space with a binary cluster in each dimension so a word can belong to 0..k clusters, but I digress... I can measure the strength of correlation between words fairly easily by counting
2011 Apr 19
2
Markov transition matrices , missing transitions for certain years
Hi all, I am working for nest box occupancy data for birds and would like to construct a Markov transition matrix, to derive transition probabilities for ALL years of the study (not separate sets of transition probabilities for each time step). The actual dataset I'm working with is 125 boxes over 14 years that can be occupied by 7 different species, though I have provided a slimmed down
2011 Jul 07
1
Select element out of several ncdf variables
Hi there I'm working with ncdf data. I have different dataset for 4 runs, 4 seasons and 3 timeslices (48 datasets in total). The datasets have the following dimensions: 96 longitudes, 48 latitudes and 30 time steps. To read all of them in, I wrote the following loop: runs <- c("03","04","05","06") years <- c(1851,1961,2061) seasons <-
2010 Apr 30
3
short question about data frame manipulation
Dear group, I am losing my mind with a simple question. Sorry if obvious, but I maybe start to be confused after days and days of reading documentations. Df : df <- structure(list(a = 1:3, b = 4:6, c = structure(c(1L, 1L, 1L), class = "factor", .Label = "w")), .Names = c("a", "b", "c"), row.names = c(NA, -3L), class =
2008 Oct 04
3
ggplot2: how to combine position=stack and position=dodge in a single graph?
Hi ggplot experts, I need to plot two time series of stacked data: a barchart with bars for each month. To compare the data of two years I need to combine both time series with in a single graph via position=doge. How should I do that? I tried the following scenario: I added two layers with the time series of the stacked data for both years. That worked well exept the bars are obscuring each
2006 Oct 27
2
Question: xyplot panel configurations for Trellis package
Hi, I am new to R community and I have a question on panel configurations in the Trellis package. Particularly, I have the following code: require(lattice) plotTable <- NULL Date <- seq(as.Date("2006-11-01"), as.Date("2009-12-01"), by = 1) nYear <- length(unique(format(Date,"%Y"))) plotTable$Date <- as.Date(paste(unique(format(Date, "%Y-%m")),
2012 Sep 13
6
[newbie] aggregating table() results and simplifying code with loop
Dear all, I'm looking for primary help at aggregating table() results and at writing a loop (if useful) My dataset ( http://goo.gl/gEPKW ) is composed of 23k rows, each one representing a point in the space of which we know the land cover over 10 years (column y01 to y10). I need to analyse it with a temporal sliding window of 5 years (y01 to y05, y02 to y06 and so forth) For each period
2005 Dec 13
4
Ploting graphics using X tints from a color
Hi, I'm trying to draw a 2D plot using multiple tints of red. The (simplified) setup is the following: || year | x | y || My idea is that each year is plotted with a different tint of red. Older year (lightest) -> Later year (darkest). I've managed to plot this with different scales of grays simply by doing: palette(gray(length(years):0/length(years))) before the plot and for each
2011 Feb 06
2
Subsampling out of site*abundance matrix
Hello, How can I randomly sample individuals within a sites from a site (row) X species abundance (column) data frame or matrix? As an example, the matrix "abund2" made below. ##### (sorry, Im a newbie and this is the only way I know to get an example on here) abund1 <- c(150, 300, 0, 360, 150, 300, 0, 240, 150, 0, 60, 0, 150, 0, 540, 0, 0, 300, 0, 240, 300, 300,