Displaying 20 results from an estimated 6000 matches similar to: "stepwise regression"
2006 Mar 11
1
Non-linear Regression : Error in eval(expr, envir, enclos)
Hi..
i have an expression of the form:
model1<-nls(y~beta1*(x1+(k1*x2)+(k1*k1*x3)+(k2*x4)+(k2*k1*x5)+(k2*k2*x6)+(k3*x7)+(k3*k4*x8)+(k3*k2*x9)+(k3*k3*x10)+ (k4*x11)+(k4*k1*x12)+(k4*k2*x13)+(k4*k3*x14)+(k4*k4*x15)+(k5*x16)+(k5*k1*x17)+(k5*k2*x18)+(k5*k3*x19)+
2008 May 19
2
Help on nested FOR loops
I am new to more radical programming in R. I am trying to write a nested 'for' loop to produce output that takes subscripts like:
for i taking values 1,2,3,4,5 and
j taking values 1,2,3
I want to output for a computation using the combination values of i and j a value x like this;
i j x
1 1 x11
1 2 x12
1 3 x13
2 1 x21
2 2 x22
2 3 x23
3 1 x31
3 2 x32
2012 Nov 28
1
Help setting optimization problem to include more constraints
Dear R-helpers,
I am struggling with an optimization problem at the moment and decided to
write the list looking for some help. I will use a very small example to
explain what I would like to. Thanks in advance for your help.
We would like to distribute resources from 4 warehouses to 3 destinations.
The costs associated are as follows:
Destination
>From 1 2 3 Total
2011 Aug 20
2
a Question regarding glm for linear regression
Hello All,
I have a question about glm in R. I would like to fit a model with glm function, I have a vector y (size n) which is my response variable and I have matrix X which is by size (n*f) where f is the number of features or columns. I have about 80 features, and when I fit a model using the following formula,?
glmfit = glm(y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + x10 + x11 + x12 + x13
2006 Nov 06
5
memory issues with new release (PR#9344)
Full_Name: Derek Elmerick
Version: 2.4.0
OS: Windows XP
Submission from: (NULL) (38.117.162.243)
hello -
i have some code that i run regularly using R version 2.3.x . the final step of
the code is to build a multinomial logit model. the dataset is large; however, i
have not had issues in the past. i just installed the 2.4.0 version of R and now
have memory allocation issues. to verify, i ran
2007 Mar 10
3
long character string problem
Hi All
I am having 2 very long character strings (550chars) and I want to put them as
expressions together with c(). The problem is that I also get these
double-quotes, as seen below in 'fct'. How can I remove these double-quotes? I
tried as.name() but it did not work (because of size?). These are creating
trouble with subsequent programs, which I tested with strings that for some
2018 Mar 14
2
truncation/rounding bug with write.csv
I don't see the issue here. It would be helpful if people would report
their sessionInfo() when reporting whether or not they see this issue.
Mine is
> sessionInfo()
R version 3.4.3 (2017-11-30)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Arch Linux
Matrix products: default
BLAS/LAPACK: /usr/lib/libopenblas_haswellp-r0.2.20.so
locale:
[1] LC_CTYPE=en_US.UTF-8
2005 Aug 15
2
queer data set
I have a dataset that is basically structureless. Its dimension varies
from row to row and sep(s) are a mixture of tab and semi colon (;) and
example is
HEADER1 HEADER2 HEADER3 HEADER3
A1 B1 C1 X11;X12;X13
A2 B2 C2 X21;X22;X23;X24;X25
A3 B3 C3
A4 B4 C4 X41;X42;X43
A5 B5 C5 X51
etc., say. Note that a blank
2018 Mar 14
2
truncation/rounding bug with write.csv
Hello, I have looked on https://www.r-project.org/bugs.html , but it seems
that this is the only way to do it.
The issue is that the precision used by write.csv is on consistant for big
files. See the following code:
First I create a large dataframe filled with random uniform values. Then I
write it to .csv and print out the first and last lines.
df = data.frame(replicate(100, runif(1000000,
2018 Mar 14
2
truncation/rounding bug with write.csv
To my surprise, I can confirm on Windows 10 using R 3.4.3 . As tail is not
recognized by Windows cmd, I replaced with:
system('powershell -nologo "& "Get-Content -Path temp.csv -Tail 1')
The last line shows only 7 digits after the decimal, whereas the first have
15 digits after the decimal. I agree with Dirk though, 1.6Gb csv files are
not the best way to work with
2018 Feb 20
5
Take the maximum of every 12 columns
Dear all,
I have monthly data in wide format, I am only providing data (at the bottom
of the email) for the first 24 columns but I have 2880 columns in total.
I would like to take max of every 12 columns. I have taken the mean of
every 12 columns with the following code:
byapply <- function(x, by, fun, ...)
{
# Create index list
if (length(by) == 1)
{
nc <- ncol(x)
2004 May 11
1
calling data frames
Dear List,
I've around 1000 *.txt files, I've generate with other software.
I've now done the following code (below).
My question is how can I automate this (with do.call () ?), so it could be
done for all the *.txt files.
Thanks in advance,
Rog??rio
names<- list.files()
file <- "BLU_Var_%04d.txt"
for(i in 1:1000){
2011 Jun 01
1
as.character limits length of result for formula
If you want a character representation of a long formula (or
a formula with long names), you can use:
as.character(my.formula)
However restriction on length of an as.character result
returns only the beginning of a long formula, and without comment.
In most cases, the following expression provides the complete
result:
paste(my.formula[[2]], " ~ ",
2010 May 11
1
Help with Names
Hi - a newbie question, if someone can please help....
I want to change X1, X2,,.....to X.1 X.2 etc in the names below. I am using
the Principal Component Regression function (pcr) and it seems to want it
this way
> datap3.pcr <- pcr(water ~ X, 10, data = datap3, Validation ="cv")
Error in model.frame.default(formula = water ~ X, data = datap3) :
invalid type (list) for
2018 Feb 20
3
Take the maximum of every 12 columns
This is what I was looking for. Thank you everyone!
Sincerely,
Milu
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2013 Jul 04
6
ggplot2
Hello Folks,
I have a database of 2000+ days with 35 observations each. I am trying to
modeling a time series by day, but it seems a problem that I don<t have the
time of the observation. I achieve something interesting by using the
barplot function, but I`d rather working with ggplot2, since I have the book
by Hadley Wickham in hands.
I start by transforming my data into a dataframe, but
2018 Feb 22
2
Sink redundant spill after RA
Hi All,
I found some cases where a spill of a live range in a block is reloaded only
in one of its successors, and there is no reload in other paths through
other successors. Since the spill is reloaded only in a certain path, it
must be okay to sink such spill close to its reloads. In the AArch64 code
below, there is a spill(x2) in the entry, but this value is reloaded only
in %bb.1, not in
2013 Apr 12
2
model frame and formula mismatch in model.matrix()
Hello everyone,
I am trying to fit the following model
All X. variables are continuous, while the conditions are categoricals.
model <- lm(X2
2018 Feb 20
0
Take the maximum of every 12 columns
Ista, et. al: efficiency?
(Note: I needed to correct my previous post: do.call() is required for
pmax() over the data frame)
> x <- data.frame(matrix(runif(12e6), ncol=12))
> system.time(r1 <- do.call(pmax,x))
user system elapsed
0.049 0.000 0.049
> identical(r1,r2)
[1] FALSE
> system.time(r2 <- apply(x,1,max))
user system elapsed
2.162 0.045 2.207
##
2018 Feb 20
2
Take the maximum of every 12 columns
Don't do this (sorry Thierry)! max() already does this -- see ?max
> x <- data.frame(a =rnorm(10), b = rnorm(10))
> max(x)
[1] 1.799644
> max(sapply(x,max))
[1] 1.799644
Cheers,
Bert
Bert Gunter
"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic