Displaying 9 results from an estimated 9 matches similar to: "function for cumulative occurrence of elements"
2010 Dec 15
1
lmList and lapply(... lm) different std. errors
Am I trying to perform multiple linear regressions on each 'VARIABLE2'. I
figured out that there are different ways, using the following code: (data
is given at the end of this message)
reg <- lapply(split(TRY, VARIABLE2), function(X){lm(X2 ~ X3, data=X)})
lapply(reg, summary)
Which produces the following:
$`1`
Call:
lm(formula = X2 ~ X3, data = X)
Residuals:
Min
2012 Sep 02
1
why variations in accuracy between R to ARCGIS for the same point reprojection?
Hi everyone,
I wonder if anyone knows the reason why the outputs of the same
reprojection in r and arcgis are different?. The magnitude of the
change can be up to 40 km in the poles.
Basically, I have a database of points equally separated by one degree
over the globe.
In ARCGIS, I am projecting the data in GCS-WGS-1984 and then
reprojected it to Berhmann to ensure equal area
2011 Dec 08
2
Relationship between covariance and inverse covariance matrices
Hi,
I've been trying to figure out a special set of covariance
matrices that causes some symmetric zero elements in the inverse
covariance matrix but am having trouble figuring out if that is
possible.
Say, for example, matrix a is a 4x4 covariance matrix with equal
variance and zero covariance elements, i.e.
[,1] [,2] [,3] [,4]
[1,] 4 0 0 0
[2,] 0 4
2003 Aug 20
2
RandomForest
Hello,
When I plot or look at the error rate vector for a random forest
(rf$err.rate) it looks like a descending function except for a few first
points of the vector with error rates values lower(sometimes much lower)
than the general level of error rates for a forest with such number of trees
when the error rates stop descending. Does it mean that there is a tree(s)
(that is built the first in
2011 Mar 05
2
Repeating the same calculation across multiple pairs of variables
Hi all,
I frequently encounter datasets that require me to repeat the same calculation across many variables. For example, given a dataset with total employment variables and manufacturing employment variables for the years 1990-2010, I might have to calculate manufacturing's share of total employment in each year. I find it cumbersome to have to manually define a share for each year and
2009 Jul 30
3
Looping through R objects with $ operator and tags
Hi all,
Suppose I want to set the values in a column to the log of the values
of another column like so:
object$LogDist <- log10(object$Distance)
How do I loop through the objects if I have object1, object2, etc to
perform this function?
object1$LogDist <- log10(object1$Distance)
object2$LogDist <- log10(object2$Distance)
object3$LogDist <- log10(object3$Distance)
I was trying to
2009 Mar 02
2
Unrealistic dispersion parameter for quasibinomial
I am running a binomial glm with response variable the no of mites of two
species y->cbind(mitea,miteb) against two continuous variables (temperature
and predatory mites) - see below. My model shows overdispersion as the
residual deviance is 48.81 on 5 degrees of freedom. If I use quasibinomial
to account for overdispersion the dispersion parameter estimate is 2501139,
which seems
2003 May 13
1
assessing the fit of a LME model
Dear All,
I would like to ask a couple of questions on a LME model.
I tested 4 selection lines at 4 food concentrations against a standard
competitor stock. I had 3 replicate cages per selection line. In each cage
I have 10 vials. I counted the number of wild type flies and competitor
stock emerging in each vial. My main question is: is there any difference
between selection lines?
I did fit
2008 Jan 21
2
experiments with slot functions and possible problems NOTE
Hello,
first of all, thanks to LT for \pkg{codeutils}. I agree that it is
indeed very useful to identify errors and also to encourage re-thinking
past solutions. My problem:
I want to compare different sets of related sub-functions which should
be used alternatively by the same top-level function. Sets of related
functions should be bound together (as lists) and the workspace should
be as clean