Displaying 20 results from an estimated 2000 matches similar to: "Turning Data Frame Columns into Vectors"
2012 Jan 08
3
Conditional Loop For Data Frame Columns
Hi,
I am trying to create a script that will evaluate each column of a data
frame, regardless of # columns, using some function and sorting the results
by an index vector:
#upload data (112 rows x 73 columns)
SD <- read.csv("/Users/johnjacob/Desktop/StudentsData_RInput.csv",
header=TRUE)
#assign index vector
ID <- SD[ ,2]
#write indexed mean function
meanfun <- function(x) {
2006 Sep 04
3
Subsetting vectors based on condition
Hello,
I have a question regarding subsetting of vectors. Here's an example of
what I'm trying to do:
vect.1 <- c(76,195, 290, 380)
vect.2 <- c(63, 95, 133, 170, 215, 253, 285, 299, 325, 375)
I would like to subset vect.2 so that it has the same length as vect.1,
and its numbers are the first corresponging higher value compared to
vect.1.
The output should be:
final.output =
2012 Jan 11
3
turning a list of vectors into a data.frame (as rows of the DF)?
As a newer R practicioner, it seems I stump myself weekly (at least) with issues that have spinning my wheels. Here is yet another... I'm trying to turn a list of numeric vectors (of uneual length) inot a dataframe. Each vector held in the list represents a row, and there are some rows of unequal length. I would like NAs as placeholders for "missing" data in the shorter vectors.
2018 May 03
4
adding overall constraint in optim()
Hi ?
This is giving me a headache. I?m trying to do a relatively simple optimization ? actually trying to approximate the output from the Excel Solver function but at roughly 1000x the speed. ?
The optimization parameters look like this. The only trouble is that I want to add a constraint that sum(wgt.vect)=1, and I can?t figure out how to do that in optim.
Mo.vect <-
2009 Aug 23
0
[LLVMdev] x86_64 darwin multilib gfortran testresults
Using the proposed patch for enabling the i386 multilib under the x86_64-apple-darwin
build...
http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-August/025040.html
the following gfortran testsuite results are obtained...
Native configuration is x86_64-apple-darwin10
=== gfortran tests ===
Running target unix/-m32
FAIL: gfortran.dg/aint_anint_1.f90 -O (internal compiler error)
FAIL:
2003 Nov 14
7
Vector indices and minus sign
Hi,
I got caught out by this behaviour in 1.8.0 and I wondered why this
happens:
I have a list of vectors and was using lapply and grep to remove
matched elements that occur in only a subset of the elements of the
list:
locs <- lapply(locs, function(x){x[- grep("^x", x)]})
The problem is that where the grep finds no matches and hence returns a
vector of length 0, all the
2008 Jun 09
1
Cross-validation in R
Folks; I am having a problem with the cv.glm and would appreciate someone
shedding some light here. It seems obvious but I cannot get it. I did read
the manual, but I could not get more insight. This is a database containing
3363 records and I am trying a cross-validation to understand the process.
When using the cv.glm, code below, I get mean of perr1 of 0.2336 and SD of
0.000139. When using a
2018 May 03
2
adding overall constraint in optim()
Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-)
> On May 3, 2018, at 3:01 PM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
>
> You can't -- at least as I read the docs for ?optim (but I'm pretty
> ignorant
2012 Dec 11
1
Rprof causing R to crash
I'm trying to use Rprof() to identify bottlenecks and speed up a particullary
slow section of code which reads in a portion of a tif file and compares
each of the values to values of predictors used for model fitting. I've
written up an example that anyone can run. Generally temp would be a
section of a tif read into a data.frame and used later for other processing.
The first portion
2018 May 06
1
adding overall constraint in optim()
Hi Michael,
A few comments
1. To add the constraint sum(wgt.vect=1) you would use the method of
Lagrange multipliers.
What this means is that in addition to the w_i (the components of the
weight variables) you would add an additional variable, call it lambda.
Then you would modify your optim.fun() function to add the term
lambda * (sum(wgt.vect - 1)
2. Are you sure that you have defined
2018 May 03
0
adding overall constraint in optim()
You can't -- at least as I read the docs for ?optim (but I'm pretty
ignorant about this, so maybe there's a way to tweak it so you can).
See here: https://cran.r-project.org/web/views/Optimization.html
for other R optimization capabilities.
Also, given your credentials, the r-sig-finance list might be a
better place for you to post your query.
Cheers,
Bert
Bert Gunter
1999 Sep 02
1
count of factors
Hello,
I was used to count how many times every factor is found the following
way :
(assuming 'vect' is a vector of factors)
tapply(vect,vect,length)
but recently I experienced weird results with this
In fact, my command line was
tapply(ORGMORE[[1]][vect],ORGMORE[[1]][vect],length)
where
- 'vect' is a vector of indices
- 'ORGMORE[[1]]' is a slightly long vector of
2018 May 04
0
adding overall constraint in optim()
On Thu, May 3, 2018 at 2:03 PM, Michael Ashton
<m.ashton at enduringinvestments.com> wrote:
> Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-)
>
I'm very confused by these statements. Most of the "finance tools"
2009 Jan 19
2
[LLVMdev] llvm-gfortran test results
The current llvm/llvm-gcc4.2 svn is now fixed with
respect to the extra warnings that were being emitted
by the gfortran compiler. The gfortran testsuite results
under Intel Darwin9 are appended below.
Jack
Native configuration is i686-apple-darwin9
=== gfortran tests ===
Running target unix/-m32
FAIL: gfortran.dg/aint_anint_1.f90 -O (internal compiler error)
FAIL:
2009 Apr 16
2
error bars in matplot
Hi,
I was trying to get error bars in my matplot. I looked at an earlier thread, and the sample code that I made is:
#------------------
library(plotrix)
mat1 <- matrix(sample(1:30,10),nrow=5,ncol=2)
ses <- matrix(sample(1:3,10,replace=T),nrow=5,ncol=2)
vect <- seq(20,100,20)
rownames(mat1) <- rownames(ses) <- vect
colnames(mat1) <- colnames(ses) <- letters[1:2]
2011 Feb 13
6
From numeric vector to string vector
Hi there, I have a numeric vector let say:
Vect <- c(12.234, 234.5675, 1.5)
Now I want a string vector like:
changedVec <- c("012.234", "234.568", "001.500")
Would be grateful if somebody help me how can I do that.
Thanks and regards,
[[alternative HTML version deleted]]
2008 Nov 02
1
[LLVMdev] llvm-2.4 prerelease gfortran results
Building the prerelease of llvm-gcc 2.4 on Intel darwin9
with the following patch...
--- llvm-gcc-4.2-2.3.999-20081024.source/gcc/stub-c.c.org 2008-10-30 18:55:45.000000000 -0400
+++ llvm-gcc-4.2-2.3.999-20081024.source/gcc/stub-c.c 2008-10-30 18:57:29.000000000 -0400
@@ -157,3 +157,27 @@
{
gcc_assert(0);
}
+
+
+bool cvt_utf8_utf16 (const unsigned char *, size_t, unsigned char **,
+
2009 Aug 04
2
can a key of a list be a variable
Hi,
I search a solution to record data in dynamic structures in R.
I have an algorithm that will be executed each step and whose output is an
array of doubles with unknown size.
The solution I found is to use lists
1) I initialise my list
l <- list()
2) and at a step numbered i I conacatain the new tab to the list
vect <- algorithm()
l <<--c( l , list(stepi=vect))
The problem is
2013 May 27
0
choose the lines
Hi,
Try this:
dat1<- read.csv("dat7.csv",header=TRUE,stringsAsFactors=FALSE,sep="\t")
dat.bru<- dat1[!is.na(dat1$evnmt_brutal),]
fun1<- function(dat){???
? ??? lst1<- split(dat,dat$patient_id)
??? lst2<- lapply(lst1,function(x) x[cumsum(x$evnmt_brutal==0)>0,])
??? lst3<- lapply(lst2,function(x) x[!(all(x$evnmt_brutal==1)|all(x$evnmt_brutal==0)),])
???
2007 Aug 10
2
need help to manipulate function and time interval
Hi R-users,
I have to define a noise level function L and its energy in the various
moment of the day by:
if time is between 18:00:00 and 23:59:59 then L[j] <- L[j]+5 and W <-
10^((L+5)/10)
if time is between 22:00:00 and 05:59:59 ==> L <- L+10 and W <-
10^((L+10)/10)
else
L=L and W = W
Could someone help me to realize this function please? You will find my
following