similar to: Define a variable on a non-standard year interval (Water Years)

Hello, I am trying to create a plot often seen in hydrodynamic work than includes a contour plot representing the water speed with arrows pointing in the direction of flow. Does anyone have any idea how I might add arrows based on wf$angle (in the example below) to the plot below? Thanks in advance! Sam library(lattice) speed <- runif(100, 0, 20) wf <- data.frame(speed) wf$width <-

Hello all, I have not been able to find an answer to this problem. I feel like it might be so simple though that it might not get a response. Suppose I have a dataframe like the one I have copied below (minus the 'calib' column). I wish to create a column like calib where I am subtracting the 'Count' when 'stain' is 'none' from all other 'Count' data for

Hello all, ## I am trying to convert some year and month data into a single variable that has a date format so I can plot a proper x axis. ## I've made a few tries at this and search around but I haven't found anything. I am looking for something of the format "%Y-%m" ## A data.frame df <- data.frame(x=rnorm(36, 1, 10), month=rep(1:12, each = 3), year=c(2000,2001,2002)) ##

Hello, I am having trouble figuring out how to convert a Day of Year integer back into a Date format. For example I have the following: date <- c('2008-01-01','2008-01-02','2008-01-03','2008-01-04','2008-01-05','2008-01-06','2008-01-07',

I have constructed a Trellis style xyplot. lengthf <- factor(length) xyplot(SLI$velocity ~ SLI$width | SLI$lengthf, layout = c(2,7), xlab = "Width (cm)", ylab = "Velocity (m/s^2)", col = "black") This produces a lovely little plot. However, the grouping factor(lengthf) isn't in the right order. My values range from 2-28 and the 2 graph on the bottom left and

Hello, I am looking for a way to subset a data frame by choosing the top ten maximum values from that dataframe. As well this occurs within some factor levels. ## I've used plyr here but I'm not married to this approach require(plyr) ## I've created a data.frame with two groups and then a id variable (y) df <- data.frame(x=rnorm(400, mean=20), y=1:400,

Good Morning, I am trying to create a new column of character strings based on the first two letters in a string in another column. I believe that I need to use some combination of ifelse and grep but I am not totally sure how to combine them. I am not totally sure why the command below isn't working. Obviously it isn't finding anything that matches my criteria but I am not sure why. Any

Hello all, This is one of those "Is there a better way to do this questions". Say I have a dataframe (df) with a grouping variable (z). This is my base data. Now I know that there is a higher order level of grouping that exist for my group variable. So what I want to do is create a new column that express that higher order level of grouping based on values in the sub-group (z in this

Hello, I am attempting to write a script that adds error bars to a barchart. I basing my attempt heavily on the following thread: http://tolstoy.newcastle.edu.au/R/e2/help/06/10/2791.html I can't seem to get around the problem that was discussed in the thread. The following example should illustrate my problem. Sorry about the messy example but I am 1) trying to make it as close as possible

Using the dataset below, I got close to what I'm after, but not quite all the way there. Any suggestions appreciated: Daily <- read.table(textConnection(" Date wyr Q 1911-04-01 1990 4.530695 1911-04-02 1990 4.700596 1911-04-03 1990 4.898814 1911-04-04 1990 5.097032 1911-04-05 1991 5.295250 1911-04-06 1991 6.569508 1911-04-07 1991 5.861587 1911-04-08 1991 5.153666

Hello, Can anyone recommend a good example of web implementation of R? Can't seem to find anything on my own. Thanks in advance! Sam [[alternative HTML version deleted]]

Hello all, I can't seem to figure out how to format a date as a title. I have something like this: plot(x=1:10, y=runif(10,1,18), main=paste(as.Date("2011-05-03", format="%Y-%m-%d"))) ## When I would really like this plot(x=1:10, y=runif(10,1,18), main=paste("May-03-2011")) ## I thought to try this but that produces an NA. plot(x=1:10, y=runif(10,1,18),

cumsum() seems to be what you need. This can probably be done more elegantly, but ... out <- aggregate(Q ~ wyr, data = Daily, which.max) tbl <- table(Daily$wyr) out$Q <- out$Q + cumsum(c(0,tbl[-length(tbl)])) out ## yields wyr Q 1 1990 4 2 1991 6 3 1992 9 4 1993 15 5 1994 18 I leave the matter of Julian dates to you or others. Cheers, Bert Bert Gunter "The trouble

Hello list, ## I have been doing the following process to convert data from one form to another for a while but it occurs to me that there is probably an easier way to do this. I am often given data that have column names which are actually data and I much prefer dealing with data that are sorted by factors. So to convert the columns I have previously made use of make.groups() in the lattice

Hello, I am having a problem making use of some data outputted from an instrument in a somewhat weird format. The instrument outputs two columns - one called JulianDay.Hour and one called Minutes.Seconds. I would like to convert these columns into a single column with a time. So I was using substr() and paste to extract that info. This works fine for the JulianDay.Hour column as there are always

Hello all, Let me first say that this isn't a question about outliers. I am using the outlier function from the outliers package but I am using it only because it is a convenient wrapper to determine values that have the largest difference between itself and the sample mean. Where I am running into problems is that I am several groups where I want to calculate the "outlier" within

Hello R list, This is a question for anyone who has used the by() command. I would like to perform a regression on a data frame by several factors. Using by() I think that I have able to perform this using the following: > lm.r <- by(master, list(Sectionf=Sectionf, startd=startd), function(x) lm (tot.c ~ starttime, data = x)) So that is, I would like to perform separate regressions for

Hello all, I need to figure out a way to lag a variable in by a number of days without using the zoo package. I need to use a remote R connection that doesn't have the zoo package installed and is unwilling to do so. So that is, I want a function where I can specify the number of days to lag a variable against a Date formatted column. That is relatively easy to do. The problem arises when I

Hi all, I'm very new to R and I'm trying to construct a threaded binary tree using recursive functions. I'm very confused was wondering if anyone had any R sample code they would share. I've come across a lot of C++ code(nothing in R) and this is not helping. best, MK -- View this message in context:

Hello guys.I just read up about tf-idf schemes and want to implement it in Xapian (with some frequently used normalizations) as it will also give me a good hang of implementing a weighting scheme before I start working on implementing DFR schemes. I read the following as references and I think Ive understood it well and can write the hack :- 1.)