search for: drobert

Displaying 17 results from an estimated 17 matches for "drobert".

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2008 Oct 24
4
gfortran optimization problems
...7. Thanks, Dave Roberts -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ David W. Roberts office 406-994-4548 Professor and Head FAX 406-994-3190 Department of Ecology email droberts at montana.edu Montana State University Bozeman, MT 59717-3460
2005 Nov 09
6
elements in a matrix to a vector
hi all, i'm trying to get elements in a matrix into a vector. i need a "streamlined" way to do it as the way i'm doing it is not very serviceable. an example is a 3x3 matrix like 0 0 3 2 0 0 0 4 0 to a vector like 3 2 4 thanks...mj [[alternative HTML version deleted]]
2007 Nov 16
4
Permutation of a distance matrix
Hi there, I would like to find a more efficient way of permuting the rows and columns of a symmetrical matrix that represents ecological or actual distances between objects in space. The permutation is of the type used in a Mantel test. Specifically, the permutation has to accomplish something like this: Original matrix addresses: a11 a12 a13 a21 a22 a23 a31 a32 a33 Example
2005 Nov 04
1
Stress in multidimensional scaling
Hello, We are trying to find a function to compute "stress" in our multidimensional scaling analysis of a dissimilarity matrix. We've used "dist()" to create the matrix and "cmdscale()" for the scaling. In order to determine the number of dimensions we would like to plot stress vs. dimensions. However, we cannot find a pre-made command. It seems that other
2006 Feb 10
1
3-d splinefun
hello, is it possible to do something like splinefun(x,y), but with a 3rd dim? for example, if i have a 2-dim system like: x<-1:100 y<-rexp(100,1) func<-splinefun(x,sort(y)) func(n) # returns interpolated value of y (after sorting) given x=n # i can check this by: plot(x,sort(y)) lines(spline(x,sort(y))) Can i do the same thing with an x,y, and z? i have found the akima
2006 Jan 17
1
Clustering function
Dear mailing group, I have loaded an Excel file into R by calling it ".csv" and using the "read.csv" function in R. However then I want to use the (limma package specific, I believe) function "hclust", which clusters data in a tree dendrogram, by similarity. However, I receive the errors msg.s: 1) "missing observations in cov/cor" 2) "In
2006 Jan 25
1
combining variables with PCA
hello R_team having perfomed a PCA on my fitted model with the function: data<- na.omit(dataset) data.pca<-prcomp(data,scale =TRUE), I´ve decided to aggregate two variables that are highly correlated. My first question is: How can I combine the two variables into one new predictor? and secondly: How can I predict with the newly created variable in a new dataset? Guess I need the
2005 Nov 02
2
help : matrix row/column random mixing
Could anybody help me in mixing the matrix values randomly (first rows and then columns)... for eg putting the 1 st row in the place of 3 rd and 3rd in place of 4 th and 4th in place of 1st row ...something like this in columns also.. Please suggest me some ways.. thanks a lot.. with regards, boopathy. --------------------------------- [[alternative HTML version deleted]]
2006 Apr 13
1
Fortran code
Hi! I have faced a big problem with R on my LINUX machine. I want to load a Fortran code via R, but the program can't do it. I have tried to load simpler codes, which seem to work perfectly, but the code I would like to load - which is a little more complicated - can't be loaded. I have installed the R 2.2.1 version. Should I need anything else to install (e.g. a library)? Is there a way
2006 Apr 12
4
Binding Text Field/Areas to Array?
Hi, If I have @answers in my Controller, which is an array of Answer model objects which don''t exist in the DB yet... How do I bind a text_area helper in the View to each Answer? (I''m pre-filling some of the Answers with other data people need to verify before submitting and will insert on POST.) I''ve been able to get the textareas to render but not with the
2005 Dec 13
3
Age of an object?
It would be nice to have a date stamp on an object. In S/Splus this was always available, because objects were files. I have looked around, but I presume this information is not available. -------------------------------------------------------------------- Trevor Hastie hastie at stanford.edu Professor, Department of Statistics, Stanford University Phone:
2006 Jan 30
2
collating columns
Dumb newbie question: I've searched the manual, R help and the mailing list archives, but can't seem to find the answer to this simple problem that I have. If I have a series of columns in a dataframe: (A, B, C ...) and I want to merge them with another series of columns (Z,Y,X ...) such that the resulting data frame has columns A,Z,B,Y,C,X ..., how do I do this? In other words, I'm
2007 Dec 17
2
Fortran 90 and Windows
...y to work? Thanks, Dave -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ David W. Roberts office 406-994-4548 Professor and Head FAX 406-994-3190 Department of Ecology email droberts at montana.edu Montana State University Bozeman, MT 59717-3460
2006 May 02
2
Concave Hull?
I am modeling a trend surface using trmat and want to trim the resulting matrix to the area enclosed by my real data (i.e., remove all the extrapolated areas). I was using chull and in.chull to calculate the convex hull and change all the other values created by trmat to NA. However, my real data has portions that are slightly concave so chull would give me slivers that are extrapolations from
2005 Nov 08
2
retrieve most abundant species by sample unit
Hi R-users: [R 2.2 on OSX 10.4.3] I have a (sparse) vegetation data frame with 500 rows (sampling units) and 177 columns (plant species) where the data represent % cover. I need to summarize the cover data by returning the names of the most dominant and the second most dominant species per plot. I reduced the data frame to omit cover below 5%; this is what it looks like stacked. I have
2005 Oct 28
3
replacing a factor value in a data frame
Hi All, I have the following problem, that's driving me mad. I have a dataframe of factors, from a genetic scan of SNPs. I DO have NAs in the dataframe, which would look like: V4 V5 V6 V7 V8 V9 V10 1 TT GG TT AC AG AG TT 2 AT CC TT AA AA AA TT 3 AT CC TT AC AA <NA> TT 4 TT CC TT AA AA AA TT 5 AT CG TT CC AA AA TT 6 TT CC TT AA AA AA TT 7 AT CC
2006 May 23
2
transpose dataset to PC-ORD?
Hello: I need to take a species-sample matrix and transpose it to the format used by PC-ORD for analysis. Unfortunately, the number of species is very large (>5000), and so this operation cannot be performed simply in an application like Excel, which has a 255 column limit. So, I wrote relatively simple code in R that I hoped would do this (appended below). But there are glitches. The