Displaying 9 results from an estimated 9 matches for "muehliman".
2009 Jul 20
5
heatmap plot
Dear R community!
I am trying to create a heatmap based on the following data. As you can see the diagonal (0,0 to 10,10) is always 0). If I run the heatmap command like i posted it I get a graph with horizontal lines.
What is my mistake?
> heatmap(activity.matrix, Rowv = NA, Colv = NA, scale="column", xlab="x Compounds", ylab="y Compounds",
2008 Sep 05
5
Lowest k values of list
Hi @ all,
how do I get the largest or lowest k values of list? It must similar to the min() / max() function, but I just don't get it.
Best wishes,
Markus
2008 Jul 26
1
Remove non-numerical columns from data frame
Hello,
My question sounds simple, but as I am desperatly searchin for a solution I am
asking you all. :)
I try to filter out all non-numeric columns of a data frame using a for loop
to go through all columns. My if clause looks like this:
for(j in 1:length(data)) {
...
if(!is.numeric(data[j])) skip <- "not numeric")
...
2008 Mar 06
0
glm.cv delta value?
Hi!
When I use the glm.cv function I get a value called "delta" which is explained as the "raw cross-validation estimate of prediction error". I recently found a formula for that term in literature where it is defined as:
alpha = 1 / N * sum over( yi - yi,pred,CV)
Well it is somehow similar to the RSS for R2 and the PRESS for Q2.
But this delta value increases with
2008 Mar 21
0
what is mvrCv PRESS?
Hello!
I have a problem with the multivariante regression function mvr (PLS
package) with leave-one-out validation.
In the value ...$validation there are the $PRESSs listed. I found in the
literature PRESS is the sum of squares of observed minus predicted. Well, I
don't understand how PRESS can grow with a better model (which indicated by
more the use of more latent variables
2010 Jan 18
2
unique: factor to string
Hi community,
I want to count the occurrence of values within a dataframe.
data$names is a list of many names. With namelist <- unique(data$names) I get all the existing names. But the result is a factor, not a list of strings.
I would then like to go trough all the names in a for-loop and count their occurrence.
How do I make this?
Best regards,
Markus
2009 Jan 21
0
cv.glm: delta squared --> squared q
Dear list members,
I am using a cross validation of a generalised linear model (glm). The cv.glm function (from boot package) returns an error as so-called ?delta? value. I would like to get to a (cross-validated) squared q, because I want to directly compare it to the squared correlation coefficient r.
I tried to find an an equation for the raw and/or adjusted cross-validation estimate of
2008 Feb 26
2
Multiple linear regression with for loop
Hi everyone!
I have an array containing the following fields for over hundred compounds:
cpd, activity, fixterm, energy1, energy2, energy3, ...
I want to run a multiple linear regression on all entries of an array. Therefore I tried to do this with a for loop. (Maybe there is a direct way of calculating it using apply, but I don't know that either.)
Actually i tried the following code:
2009 Jan 20
5
Error message from CV.GLM
Dear list members.
I have problems with the usage of cv.glm from the boot package. Here are some parts of the script I wanted to use:
data <- read.table("selected_2D.csv", header=TRUE, sep=",")
?
glm.fitted <- glm("ydata$ y ~ 1 + density + vsurf_ID6 + vsurf_S ", data=data)
error <- cv.glm(data=data, glm.fitted, K=6)
ydata$y is a separate data set, where