Displaying 20 results from an estimated 1000 matches similar to: "Generating artificial datasets with a specific correlation coefficient."
2005 Feb 11
3
Saving graphs in formats other than PDF?
I am running R 2.01 on Mac OS 10.3.7. Whenever I save graphs, they are
saved as PDF files. Are there any other file formats to which I could save
my graphs. I would like to directly export my graphs to MS Word, if
possible.
Thank you in advance.
Sincerely,
Jim Milks
Graduate Student
Environmental Sciences Ph.D. Program
Wright State University
3640 Colonel Glenn Hwy
Dayton, OH 45435
2005 May 31
2
plane3d
I am attempting to fit a logistic regression plane to a 3-D scatterplot
(which was generated using scatterplot3d). I've noticed that the help
pages of scatterplot3d include a function titled "plane3d." However,
when I attempt to use the function, I get the following message:
Error: couldn't find function "plane3d"
I've searched the archives and found no
2007 Aug 13
2
Error message when using zero-inflated count regression model in package zicounts
I have data on number of vines per tree for ~550 trees. Over half of
the trees did not have any vines and the data is fairly skewed
(median = 0, mean = 1.158, 3rd qu. = 1.000). I am attempting to
investigate whether plot location (four sites), species (I'm using
only the four most common species), or tree dbh has a significant
influence on the number of vines per tree. When I
2007 Jul 02
4
Extracting sums for individual factors in data frames
I have a data frame with two columns, one of which is a factor
(Species) and the other is numeric (BA, which stands for basal
area). Here's a sample:
Species BA
ACSA 55.7632696
FRAM 122.9933524
ACSA 67.54424205
ACSA 89.22123136
ACSA 82.46680716
ACSA 22.46238747
ACSA 19.94911335
ACSA 20.42035225
ACSA 19.00663555
ACSA 21.67698931
ACSA 57.80530483
ACSA 30.31636911
Dead 43.98229715
Dead
2005 Apr 18
1
Forcing best-fit lines to go through the origin
Dear All,
I have a rather unusual problem. I have a set of data for a class in
subsurface processes. From that dataset, I must calculate the slope of
the best-fit line (which is the parameter of interest). The problem I
have is twofold: 1) for the purposes of the exercise, I must force my
best-fit line to go through the origin (0,0), and 2) the line must be
linear, even though the data is
2007 Jul 08
1
generating a data frame with a subset from another data frame
R gurus,
I have a data set that looks something like this:
Site Species DBH #Vines
G PLOC 45.9 4
G ACNE 23.3 1
G ACNE 12.0 0
G FRAM 35.9 5
G AEGL 11.2 2
N PLOC 77.3 12
N JUNI 78.6 7
N ACNE 18.9 1
N ACNE 15.7 3
N ACRU 35.5 4
H ACSA2 24.1 6
H ULAM 35.2 7
There are 730 individual trees (22 species) from four sites in the
actual data set. I would like to create a second data frame that
2007 Jul 31
2
choosing between Poisson regression models: no interactions vs. interactions
R gurus,
I'm working on data analysis for a small project. My response
variable is total vines per tree (median = 0, mean = 1.65, min = 0,
max = 24). My predictors are two categorical variables (four sites
and four species) and one continuous (tree diameter at breast height
(DBH)). The main question I'm attempting to answer is whether or not
the species identity of a tree has
2011 Feb 20
8
Generating uniformly distributed correlated data.
I wish to generate a vector of uniformly distributed data with a
defined correlation to another vector
The only function I have been able to find doing something similar is
corgen from the library ecodist.
The following code generates data with the desired correlation to the
vector x but the resulting vector y is normal and not uniform
distributed
library(ecodist)
x <- runif(10^5)
y
2007 Aug 31
1
Strange behavior using subset
Dear R Gurus,
Let's get the technical details out of the way first:
Computer: 1.83 GHz MacBook
R version 2.5.1
I have a data set that contains the following variables: site,
species, total.vines. I need to partition the main data set by site,
the further select only those species that occurred at each site.
When I select by site (site.name<-subset(data frame,Site=="Site
2007 Oct 17
1
correlated data
Hi!!
I am trying to generate data with specific correlation using corgen method from the ecodist package. It does not seem to generate the data properly. I am listing the code below. Secondly, when I put the code given below all in one file and source it, it is unable to complete the task. But when I execute it one at a time it is able to complete it. Can someone point out any mistake that I may
2005 May 01
1
Partial F-test comparing full and reduced regression models
Dear all:
I have a regression model that has collinearity problems (between three
regressor variables). I need a F-test that will allow me to compare
between full (with all variables) and partial models (minus 1=<
variables). The general F-test formula I'm using is:
F = {[SS(full model) - SS(reduced model)] / (#variables taken out)} /
MSS(full model)
Unfortunately, the ANOVA table
2013 Mar 05
3
Simulate binary correlated data
Dear R experts,
I am trying to simulate correlated binary data and have stumbled upon the
following problem:
With the help of "binarySimCLF" or "mvpBinaryEp" I have been able to
simulate correlating binary vectors given certain mean values and a desired
correlation. My problem is that these procedures do not allow you to specify
the exact vector for which you want to generate
2012 Mar 15
6
Generation of correlated variables
Hi everyone.
Based on a dependent variable (y), I'm trying to generate some independent
variables with a specified correlation. For this there's no problems.
However, I would like that have all my "regressors" to be orthogonal (i.e.
no correlation among them.
For example,
y = x1 + x2 + x3 where the correlation between y x1 = 0.7, x2 = 0.4 and x3 =
0.8. However, x1, x2 and x3
2009 Nov 25
3
Random data
Hi,
how can I produce random data which lies around a straight line with angle
45 degree.
Similar to this image: http://zoonek2.free.fr/UNIX/48_R/g134.png
Cheers
--
View this message in context: http://old.nabble.com/Random-data-tp26513822p26513822.html
Sent from the R help mailing list archive at Nabble.com.
2011 Dec 03
1
partial mantel tests in ecodist with intential NA values.
I would like to perform partial mantel tests on only within group values, with "between group" values assigned to NA.
This is possible in package ncf partial.mantel.test, however this sues a different permutation to that used in ecodist.ecodist will not accept data with NA values, returning a "matrix is not square error.
is it possible to perform this test in ecodist?
many thanks
2008 Aug 28
3
Upgrading R means I lose my packages
The title says it all. Does anyone know of a way to save your
packages when you upgrade to a new version of R? This may seem petty,
but I'm accumulating enough packages that having to download and
install each of them anew every time I install a new version of R is
rather of a pain. Ideally, I would like the new version of R to
recognize the packages I've installed on the
2008 Apr 14
1
Vegan R^2 and tau values for metaMDS
I am using the function metaMDS with jaccard distances to ordinate a
set of constituent by site matrix. I can post this data if it would
be helpful, but it is large to include in an email. I can also
provide reproducable code if necessary. I would like to get an R^2
value for the axes of the ordination configuration that I get with
metaMDS in the vegan package is there a way to do this- is it
2011 Oct 16
2
How to plot CI's (llim ulim) on ecodist mgram
I would like to put confidence intervals on a mantel corellogram
they are already calculated in the pmgram object but I am unsure how I
get the x value in order to plot them?
package(ecodist)
X<-1:100
Y<-rnorm(1:100)
Z<-rnorm(1:100)
XY<-dist(data.frame(X,Y))
YX<-dist(data.frame(Y,X))
my.mgram<-mgram(XY,XZ)
plot(my.mgram)
print(my.mgram)
> print(my.mgram)
$mgram
2011 Jan 20
1
Problems with ecodist
Dear Dr.Goslee and anyone may intrested in matrix manipulate,
I am using your ecodist to do mantel and partial mantel test, I have
locality data and shape variation data, and the two distance matrixs are
given as belowings. When I run the analysis, it is always report that the
matrix is not square, but I didn't know what's wrong with my data. Would you
please help me on this. I am quite
2010 Dec 14
3
from table to matrix
I have a table like this:
Date TIME Q
A a 1
A b 2
A c 3
B a 4
B b 5
B c 6
C a 7
C b 8
C c 9
I want use R language to turn it to a matrix like :
a b c
A 1 2 3
B 4 5 6
C 7 8 9
I am new to R , anyone can help? Thanks in advance! have a table like this:
Date TIME Q
A a 1
A b 2
A c 3
B a