Displaying 20 results from an estimated 4000 matches similar to: "Correlation with small N"
2008 May 17
1
Correlated Columns in data frame
Dear all,
Sorry to post my query once again in the list, since I did
not get attention from anyone in my previous mail to this
list.
Now I make it simple here that please give me a code for
find out the columns of a dataframe whose correlation
coefficient is below a pre-determined threshold. (For
detailed query please see my previous message to this list,
pasted hereunder)
Thanks and regards,
2009 Jun 14
1
Identifying clusters of size n
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Is there a library which is capable of identifying distinct clusters of size n
from a series of XY coordinates?
Failing this, I'd like to be able to to something like:
Using a sliding window of size n along the x-axis I'd like to determine the
distance between the center of the points in the window and the closest point
outside the window. I
2003 Nov 21
3
speeding up a pairwise correlation calculation
Hi,
I have a data.frame with 294 columns and 211 rows. I am calculating
correlations between all pairs of columns (excluding column 1) and based
on these correlation values I delete one column from any pair that shows
a R^2 greater than a cuttoff value. (Rather than directly delete the
column all I do is store the column number, and do the deletion later)
The code I am using is:
ndesc
2006 Apr 20
2
nls and factor
Is it possible to include a factor in an nls formula?
I've searched the help pages without any luck so I
guess it is not feasible.
I've given it a few attempts without luck getting the
message:
+ not meaningful for factors in:
Ops.factor(independ^EE, a)
This is a toy example, my realworld case is much more
complicated (and can not be solved linearizing an
using lm)
2002 Apr 18
2
Data.Frame Multiplication
Have got any R-proffessional a starting point for me
how i can write me a function which multiply every column with
every other column in the data.frame - indenpendent from the dim's .
Thanks in advance
regards,Christian
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2011 Apr 22
2
How to answer the question about transitive correlation?
Hi, everyone. I know it may be a basic statistical question. But I can't
find a good answer.
I have a question raised by one of the reviewers.
Factor A expression was strongly correlated with B expression (chi-square)
in this series. Prior reports by the same authors showed that B expression
strongly correlated with survival (Log-rank). Please provide an explanation
why then were the results
2009 Mar 27
1
ROCR package finding maximum accuracy and optimal cutoff point
If we use the ROCR package to find the accuracy of a classifier
pred <- prediction(svm.pred, testset[,2])
perf.acc <- performance(pred,"acc")
Do we?find the maximum accuracy?as follows?(is there a simplier way?):
> max(perf.acc at x.values[[1]])
Then to find the cutoff point that maximizes the accuracy?do we do the
following?(is there a simpler way):
> cutoff.list <-
2023 Oct 15
2
Create new data frame with conditional sums
Under the hood, sapply() is also a loop (at the interpreted level). As
is lapply(), etc.
-- Bert
On Sun, Oct 15, 2023 at 2:34?AM Jason Stout, M.D. <jason.stout at duke.edu> wrote:
>
> That's very helpful and instructive, thank you!
>
> Jason Stout, MD, MHS
> Box 102359-DUMC
> Durham, NC 27710
> FAX 919-681-7494
> ________________________________
> From: John
2023 Oct 16
1
Create new data frame with conditional sums
If one makes the reasonable assumption that Pct is much larger than
Cutoff, sorting Cutoff is the expensive part e.g O(nlog2(n) for
Quicksort (n = length Cutoff). I believe looping is O(n^2). Jeff's
approach using findInterval may be faster. Of course implementation
details matter.
-- Bert
On Mon, Oct 16, 2023 at 4:41?AM Leonard Mada <leo.mada at syonic.eu> wrote:
>
> Dear
2009 Jul 23
1
ROCR - confidence interval for Sens and Spec
Dear List,
I am new to ROC analysis and the package ROCR. I want to compute the confidence intervals of sensitivity and specificity for a given cutoff value. I have used the following to calculate sensitivity and specificity:
data(ROCR.simple)
pred <- prediction(ROCR.simple$predictions, ROCR.simple$labels)
se.sp <- function (cutoff, performance) {
sens <-
2023 Oct 16
1
Create new data frame with conditional sums
Dear Jason,
The code could look something like:
dummyData = data.frame(Tract=seq(1, 10, by=1),
?? ?Pct = c(0.05,0.03,0.01,0.12,0.21,0.04,0.07,0.09,0.06,0.03),
?? ?Totpop = c(4000,3500,4500,4100,3900,4250,5100,4700,4950,4800))
# Define the cutoffs
# - allow for duplicate entries;
by = 0.03; # by = 0.01;
cutoffs <- seq(0, 0.20, by = by)
# Create a new column with cutoffs
dummyData$Cutoff
2014 Apr 15
6
[PATCH 0/3] misc. cleanup
Hello,
some misc. cleanup patches for speexdsp, nothing big
I'm not sure about how to submit patches, so this is a test balloon :)
ultimately, I'd like to fix the FIXED_POINT issue, see
http://lists.xiph.org/pipermail/speex-dev/2013-December/008465.html
currently, I think the only way to find out how speexdsp has been compiled is
to resample some bytes and observe the output; which is
2023 Oct 14
1
Create new data frame with conditional sums
That's very helpful and instructive, thank you!
Jason Stout, MD, MHS
Box 102359-DUMC
Durham, NC 27710
FAX 919-681-7494
________________________________
From: John Fox <jfox at mcmaster.ca>
Sent: Saturday, October 14, 2023 10:13 AM
To: Jason Stout, M.D. <jason.stout at duke.edu>
Cc: r-help at r-project.org <r-help at r-project.org>
Subject: Re: [R] Create new data frame with
2023 Oct 14
2
Create new data frame with conditional sums
Well, here's one way to do it:
(dat is your example data frame)
Cutoff <- seq(0, .15, .01)
Pop <- with(dat, sapply(Cutoff, \(p)sum(Totpop[Pct >= p])))
I think there must be a more efficient way to do it with cumsum(), though.
Cheers,
Bert
On Sat, Oct 14, 2023 at 12:53?AM Jason Stout, M.D. <jason.stout at duke.edu> wrote:
>
> This seems like it should be simple but I
2009 Aug 17
1
how to pass more than one argument to the function called by lapply?
Dear R helpers:
I wonder how to pass more than one argument to the function called by
lapply.
For example,
#R code below ---------------------------
indf <- data.frame(id=I(c('a','b')),y=c(1,10))
#I want to add an addition argument cutoff into the function called by
lapply.
outside.fun <- function(indf, cutoff)
{
unlist(lapply(split(indf, indf[,'id']),
2023 Oct 15
1
Create new data frame with conditional sums
Dear Jason,
I do not think that the solution based on aggregate offered by GPT was
correct. That quasi-solution only aggregates for every individual level.
As I understand, you want the cumulative sum. The idea was proposed by
Bert; you need only to sort first based on the cutoff (e.g. using an
ordered factor). And then only extract the last value for each level. If
Pct is unique, than you
2010 Jun 30
1
vlmc - "In vlmc(traffic.clusters.stationary, cutoff = i) : alphabet with >1-letter strings; trying to abbreviate"
Dear all (copying the package author),
I have a question on the vlmc package. I am trying to model a time series, where each element can take one of 11 values (the result of some clustering). When I run the following command (synthetic data to facilitate self-contained example) I get the following warning: ("alphabet with >1-letter strings; trying to abbreviate")
+++ START+++
>
2001 Jul 31
4
nlme: bug in getCovariateFormula (PR#1038)
I found that predict.gnls failed with a wierd error message about a
non-numeric argument to a binary vector in one of three nearly identical
uses.
Error in Inh/Ki : non-numeric argument to binary operator
(Inh and Ki are arguments to the function used in the formula for the
object whose predictions were requested).
It turns out that the problem is in getCovariateFormula().
The final line in
2006 Jul 24
1
deparse - width.cutoff
I have a question about "deparse" function in R
What is the reason that "deparse" use an argument like "width.cutoff" ?
Why the maximum cutoff is 500?
I was manipulating an R formula and used "deparse". Since the length of user's formula was greater then 500, my code didnt work.
thanks
Johan
johan Faux <johanfaux@yahoo.com> wrote: I have a
2023 Oct 13
1
Create new data frame with conditional sums
This seems like it should be simple but I can't get it to work properly. I'm starting with a data frame like this:
Tract Pct Totpop
1 0.05 4000
2 0.03 3500
3 0.01 4500
4 0.12 4100
5 0.21 3900
6 0.04 4250
7 0.07 5100
8 0.09