similar to: Probability of exceedance function question

Displaying 20 results from an estimated 800 matches similar to: "Probability of exceedance function question"

2006 Oct 10
1
How to assign a rank to a range of values..
>From the following: basin.map <- readAsciiGrid("c:/temp/area.asc", colname="area") I have a SpatialGridDataFrame which has the x and y cordinate of a cell, and the drainage area of that cell. There are many cells with a low drainage area (in my case, 33000 with an area of 37.16) and one cell with the highest drainage area (again, in my case, a drainage area of of
2009 Jan 28
2
Logical subset of the columns in a dataframe
Hi R-helpers, I've been struggling with a problem for most of the day (!) so am finally resorting to R-help. I would like to subset the columns of my dataframe based on the frequency with which the columns contain non-zero values. For example, let's say that I want to retain only those columns which contain non-zero values in at least 1% of their rows. In Excel I would calculate a row
2006 May 03
2
Nested model and variance partitioning
Dear R users, I face to a nested pattern and despite the numerous examples in the help I am still confused. I sampled bugs in different habitats within sites which were within rivers themselves within different regions. The habitat correspond to different substrata (not systematically present in all sites). For rivers and sites, I have environemental variables (e.g. altitude and slope of
2010 Aug 25
1
SEM : Warning : Could not compute QR decomposition of Hessian
Hi useRs, I'm trying for the first time to use a sem. The model finally runs, but gives a warning saying : "In sem.default(ram = ram, S = S, N = N, param.names = pars, var.names = vars, : Could not compute QR decomposition of Hessian. Optimization probably did not converge. " I found in R-help some posts on this warning, but my attemps to modify the code didn't change
2017 Oct 05
3
working with ordinal predictor variables?
I'm trying to develop a linear model for crop productivity based on variables published as part of the SSURGO database released by the USDA. My default is to just run lm() with continuous predictor variables as numeric, and discrete predictor variables as factors, but some of the discrete variables are ordinal (e.g. drainage class, which ranges from excessively drained to excessively poorly
2009 Feb 15
1
MDS with ranking data (and transformation)
Dear Sirs and madams :-) I am trying to teach myself multidimensional scaling. To that effect I have collected a survey asking people to rank 10 philosophers and politicians according to their preference. I have collected 61 answers. The data is organized in ten columns and 61 rows. the columns are "choice_1", "choice_2", "choice_3" etc. The cells is the name of the
2010 Oct 05
1
Ordering Duplicates for Selection
Hi all, I've found a lot of helpful info regarding identifying and deleting duplicates but I'd like to do something a little different - I'd like to identify the duplicate values but instead of deletion, label them with a value. I am working with historical data regarding school courses: Student Number Course Final Mark
2010 May 29
1
Help with R graphics
I need to make a plot illustrating main characterisitig of river drainage data. For this I have 2 questions: how can I rotate a histogram -90? (or 270?) (like the horizontal=TRUE with plot)? how can I use split.screen to produce 3 plot with uneuqal size (1/5, 2/5, 2/5 of the screen width)? thank you very much in advance for your help fabian
2004 Aug 31
1
appending data to a dataframe
Dear R users, I am sorry to ask you such a pathetic newbie question, but how does one append data at the end of a data frame? I am working with GRASS/R library, but the question is about R. I have a data.frame containing the following variables basinID, distoutlet, drainage_area, slope These variables are stored for all pixels of Grass Raster objects. For each drainage basin (basinID), I'd
2006 Jan 05
2
New logo for CentOS
To celebrate CentOS as the greatest thing since sliced bread, we should endevour to have a new logo in place. Whilst the current one suffices, a new logo/favicon should be in place. My artistry skills are not good (i was eating hotdogs whilst the rest of the class learned fine art), so those of you artistically endowed should come up with something.
2017 Oct 05
0
working with ordinal predictor variables?
I would consider this is a question for a statistics forum such as stats.stackexchange.com, not R-help, which is about R programming. They do sometimes intersect, as here, but I think you need to *understand what you're doing* before you write the R code to do it. Obviously, IMO. Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and
2005 Feb 08
1
astcc with multiple access
I'm looking at astcc and it seems that setting up a script that will allow multiple people to access a calling card simultaneously would be fairly difficult. Before I endevour to develop this, has anyone already done it/looked at this/can point me in the right direction? Thanks. -- Mike Nugent <asterisk@illuminatus.org>
2007 Nov 14
1
reading tables from url
I'm trying to read some web tables directly into R. These are both genome sequencing projects (eukaryotes and metagenomes) from NCBI and look very similar; however, only the first one works. http://www.ncbi.nlm.nih.gov/genomes/leuks.cgi http://www.ncbi.nlm.nih.gov/genomes/lenvs.cgi I added ?dump=selected to the end of the url string to get a tab- delimited file (which is what happens
2013 Apr 04
2
custom startup/welcome message
hi everybody I wonder if there is a simple way, but not simple would be ok too, to customize info/welcome page at session start time? what I'd like to do is to put together simple short howto / dos & don'ts page for users, I'm thinking it would be great if it was possible many thanks [[alternative HTML version deleted]]
2007 Jun 12
0
nlme model
I am having trouble figuring out the right form for the nlme arguments. I do have examples in Modern and Applied Statistics with S and from other sources, but 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
2007 Jul 18
0
multicollinearity in nlme models
I am working on a nlme model that has multiple fixed effects (linear and nonlinear) with a nonlinear (asymptotic) random effect. asymporig<-function(x,th1,th2)th1*(1-exp(-exp(th2)*x)) asymporigb<-function(x,th1b,th2b)th1b*(1-exp(-exp(th2b)*x)) mod.vol.nlme<-nlme(fa20~(ah*habdiv+ads*ds+ads2*ds2+at*trout)+asymporig(da.p,th1,th2)+ asymporigb(vol,th1b,th2b),
2001 Nov 07
2
Filtering data
Hello, I am having difficulty filtering data. I am working with flow data collected at a stream gage. For each record, I have a date and flow value. I have filtered this data to only include days when flow values exceed a given threshold. Here is my problem. Within this subset of data, I often have several consecutive days above the threshold. From this group of days, I wish to select the
2005 Mar 13
1
Incorrect calculation of loop in R.2.0.1 (PR#7724)
Full_Name: Ms. Drakes Version: 2.01 OS: Windows XP Submission from: (NULL) (4.237.32.239) file="C:/glob.csv" glob=read.csv(file,header=T) y=glob$Temperature z=max(y[1:40]) # this has a probability of exceedance of 1/41 # now you can check how this does in the 2nd sample - sum=0 for i = 41:100 if (z>y[i]sum=sum+1 sum sum=sum/60 sum error: the loop i=41:100 does not work
2004 Jan 05
0
Samba 3.0.1 ADS/Kerberos problems relating to Win2k/xp browsing to samba server
Hello All, I've been discovering the joys of Samba/ADS integration here (the environment is a chip design concern that has chip simulation tools, many of which run in Linux, but some of which only run in Windows. Winbind, and a Linux based NAS server are the cornerstone through which Windows and Linux elements of the toolchain will be able to seamlessly communicate, once we get all the
2005 Sep 15
4
Error in vector("double", length) : vector size specified is too large....VLDs
I have what R seems to consider a very large dataset, a 12MB text file of lat,long,and height values, 130,000 rows to be exact. Here's what I get: Thomas Colson North Carolina State University Department of Forestry and Environmental Resources (919) 673 8023 tom_colson at ncsu.edu Calendar: www4.ncsu.edu/~tpcolson