search for: watersheds

Hello, Is R very compatible with a Mac? A colleague of mine indicated that everyone he knows with a Mac has problems with R. What can you tell me about using R with a Mac. What do I need to download? I have downloaded the basic R package. Thanks, -- Tiffany Kinder MS Student Department of Watershed Science Utah State University tiffany.kinder@aggiemail.usu.edu [[alternative HTML version

...drologist, but not a professional statistician. Yet I find myself using statistical tools at least part of the time. My discovery of the R-project through a friend has been most helpful. Here is my problem: I'm tasked with fitting a dataset comprising correlated discharges from adjacent watersheds to bivariate normal and bivariate Gumbel distributions (data untransformed and then log-transformed to reduce skew). (In addition, I'm tasked with exploring a couple of Archimedian copulas to link univariate Pearson Type III distributions fit to log- transformed discharges, but that'...

I issued the following command to obtain the std dev for each month. psd<-numSummary(Sal, groups=month, statistics=c("sd")) which resulted in > psd sd n NA 1 6.930340 9367 2319 2 7.847003 10827 1008 3 5.962308 12988 404 4

My x axis is a series of daily dates (e.g., 01/01/2000, 01/02/2000, etc.) from 2000 to end of 2008. The default only gives me 4 ticks. I want more. Why doesn't this work? sdate<-as.POSIXct(strptime(date,format="%m/%d/%Y")) plot(ppt~sdate,type="l",ylim=c(0,47),col=1,lwd=1,pch=16,ylab="Salinity, psu",xlab="Year",las=1,main="Duck Key

Dear R-help: Does anyone know of a package in R that will do Welch's modified F-test for heterogeneous error variances? Are there other statistical techniques available in R that test the equality of means when homoscedastisity is violated? 't.test' does this in the pairwise sense when var.equal = TRUE. With best wishes and kind regards I am Sincerely, Corey A. Moffet Support

Dear R-Help, Does anyone know of a way to use CGIwithR in Windows? David Firth the author of CGIwithR states "It ought to be possible to adapt it for use also in conjunction with web servers running under Windows NT ... but the author has no plans for that." I have developed some applications in R that I would like to make available through a web interface using CGIwithR but at this

...I still can't figure it out. I am trying to estimate species richness (sr) in streams across minnesota. My predictor variables are depth (d), habitat diversity (habdiv), drainage area (da) and an indicator variable representing the watershed/basins that the streams are in (bas: there are 10 watersheds). The variable explaining the greatest amount of variation appears to be da. I have used a log(da) to linearize the relationship, but an asymptotic relationship is more appropriate. I have used nls: B<-c(.007,1,3,2,2,2,2,2,2,2,2,2,.05,.001,.8) st<-list(ad=B[1],ahabdiv=B[2],abas=B[3:12],b=B...

I have 3 columns: flow, month, and monthname, where month is 1-12, and monthname is name of month. I can't get the plot to replace the 1-12 with monthname using ticks.lab. What am I doing wrong? plot(flow~factor(month),xlab="Month",ylab="Total Flow per Month", ylim=c(0,55000), ticks.lab="monthname") Thanks Gregory A. Graves Lead Scientist REstoration

I'm using R 1.6.2 on a Windows 2000 machine. I've plotted the results of an MDS run labeled by a numerical ID, and color coded by a group code: plot(cv.mds.spr$points, type="n", main="Non-Metric Multidimensional Scaling of SprRun CV Watersheds") text(cv.mds.spr$points, labels = as.character(cv.wshed.id.spr), col = codes(cv.wshed.grp), cex=.75) Question is, how do I get the legend to match the color codes? I have tried different permutations of the following: leg.txt <- c("LSSJ.NS","LSSJ.SS","US.RD&quot...

I have a set of 52 weekly values, one is the desired high lake stage for a week, and the other is the desired low lake stage for each week. It looks like this: week High Low 1 16 14.5 2 16 14.5 3 15.95 14.45 4 15.84 14.34 5 15.73 14.23 6 15.61 14.11 7 15.5 14 8 15.38 13.88 9 15.25 13.75 10 15.13 13.63 .... 52 15 13.5 I can plot out two nice curves

Dear R help, In the middle of my session, I started receiving the error message "bad value" regardless of what I entered. I had to close R and restart it. When the error occurred, I was creating basic lattice plots, with no other add-on packages running. I am running R through John Fox's XEmacs interface, XEmacs version 21.4.20 on a Windows XP Pro machine with 2 GB of RAM. I have

Dear HelpeRs: I have a data set in the following format, which will be familiar to those of you working with NCDC climate data. Example: Year <- rep(1:3, each = 3) Year <- c(Year,Year) ID <- rep(1:2, each = 9) Jan <- runif(18, min = 0, max = 20) Feb <- runif(18, min = 0, max = 20) Mar <- runif(18, min = 0, max = 20) var <- gl(3,1,18,label =

Dear exports,I have created a hypsometric curve (area-elevation curve) for my watershed by using simple command hypsometric(X,main="Hypsometric Curve", xlab="Relative Area above Elevation, (a/A)", ylab="Relative Elevation, (h/H)", col="blue")It plots the hypsometric curve in "RGraphics window", My question is how can I export values which is used

On Mon, Apr 13, 2009 at 12:41 PM, Dan Dube <ddube-at-advisen.com> wrote: > i use tapply and by often, but i always end up banging my head against > the wall with the output. The proposed solution of Dan's problem posted on R-help was: > do.call(rbind,a) When I use this 'solution' I get 'ERROR: second argument must be a list'. So head on wall continues. My

The USDA-Agricultural Research Service, Southeast Watershed Research Unit in Tifton, GA, is seeking a postdoctoral research associate for a full-time, 2 year appointment. The research associate will develop, calibrate, and validate a semi-empirical model for estimating cotton biomass from fields within the southeastern United States. Model development will involve the use of optical and radar

I am having trouble using get.arcdata() in RArcInfo. X and y coordinates are not what they should be. Can anyone suggest what might be wrong? I am using RArcInfo 0.4-1. Here is the metadata of my coverage, using describe in Arc: Arc: describe stdir_6 Description of SINGLE precision coverage stdir_6 FEATURE CLASSES

Dear R-help, Does any one know of a function/package in R that will test the assumption of spericity in a split-plot analysis of variance? How are people dealing with this issue in R? With best wishes and kind regards I am Sincerely, Corey A. Moffet Support Scientist University of Idaho Northwest Watershed Research Center 800 Park Blvd, Plaza IV, Suite 105 Boise, ID 83712-7716 (208) 422-0718

The funciton c() works differently for strings and for factors: For strings: > l = c('a', 'b') > l [1] "a" "b" For factors: > l = c(factor('a'), factor('b')) > l [1] 1 1 What should be the right technique for merging factors? -- Svetlana Eden Biostatistician II School of Medicine

Dear R-users, I've spent most of the day reading R documentation at length but couldn't find something perhaps obvious. I have a dataset made of 3 morphometric variables for a series of watershed [log(slope); log(drainage_area); distance_to_outlet] My aim is to predict the value of log(slope) for pairs of [drainage_area; distance_to_outlet] (sounds like a plain linear model fitting,

I have been using a nlme model and wish to specify the correlation structure. My data is grouped (bas), but I have no time component or adequate spatial description beyond the grouping variable. So I chose the simplest structure and updated my original nlme model by: update(model, corr=corCompSymm(~1|bas)) This is not significant. One of my variables measures area upstream of the sample. Area