Displaying 20 results from an estimated 2000 matches similar to: "Relase positive with log and zero of negative with 0"
2008 May 27
4
help with simple function
I have a matrix of frequency counts from 0-160.
x<-as.matrix(c(0,1,0,0,1,0,0,0,1,0,0,0,0,1))
I would like to apply a function creating a new column (x[,2])containing
values equal to:
a) log(x[m,1]) if x[m,1] > 0; and
b) for all x[m,1]= 0, log(next x[m,1] > 0 / count of preceding zero values
+1)
for example, x[1,2] should equal log(x[2,1]/2) = log(1/2) = -0.6931472
whereas x[3,2] should
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
2017 Jun 08
3
Math ops behaviour with multiple classes
I would expect that several math operations should always return values
with a class of numeric. If the input is defined with multiple classes,
however, the class attribute is preserved. I would think this may have
some unintended side-effects. Here's an example:
> sessionInfo()$R.version$version.string
[1] "R version 3.4.0 (2017-04-21)"
> x <- seq.int(5)
>
2017 Jun 08
0
Math ops behaviour with multiple classes
I think you may be confusing (S3) class and ?mode.
> x <- seq.int(1:3)
> class(x)
[1] "integer"
> mode(x)
[1] "numeric"
> class(x+.5) ## coercion
[1] "numeric"
> mode(x+.5)
[1] "numeric"
But note:
> y <- as.integer(1)
> class(y)
[1] "integer"
> class(y) <- "foo"
> mode(y)
[1] "numeric"
>
2008 Oct 03
1
NA's in segmented
I am trying to fit a very simple broken stick model using the package
"segmented" but I have hit a roadblock.
> str(data)
'data.frame': 18 obs. of 2 variables:
$ Bin : num 0.25 0.75 1.25 1.75 2.25 2.75 3.25 3.75 4.25 4.75 ...
$ LnFREQ: num 5.06 4.23 3.50 3.47 2.83 ...
I fit the lm easily:
> fit.lm<-lm(LnFREQ~Bin, data=id07)
But I keep getting an error
2017 Jun 08
1
Math ops behaviour with multiple classes
Thanks Bert, I think we agree on the current behaviour, but I'm still not sure if it's desirable. The mode isn't used for method dispatch. In the following example, I have to write `log.foo` in order for the correct method to be called.
> x <- seq.int(5)
> class(x) <- c("integer", "foo")
> half <- function(x) UseMethod("half")
>
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
2011 Mar 21
1
GSOC 2011 - QueryParser Reimplementation
hello everyone,
I am Maheshwar, a prefinal year Computer Science undergraduate student at
BITS-Pilani, India. When i was going through the GSOC ideas , i felt
interested in Quesry parser project. Till now i have implemented a couple of
LL(1) parsers as a part of my assignment in Compiler construction course,
so i would love to join and contribute to this project. So can any one tell
me how to go
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
2005 Jul 13
2
Kronecker matrix product
Hi
I want to write a little function that takes a matrix X of size
m-by-n, and a list L of length "m", whose elements are matrices all
of which have
the same number of columns but possibly a different number of rows.
I then want to get a sort of dumbed-down kronecker product in which
X[i,j] is replaced by X[i,j]*L[[j]]
where L[[j]] is the j-th of the "m" matrices. For
2009 Oct 16
1
Converting dataframe to matrix
Hi,
I'm experimenting with a few learners that require a matrix as their
input. (Currently svmpath, vbmp, etc.)
I currently have a dataframe with 50 columns and 20,000 rows.
I tried using:
x <- as.matrix(my_data.frame)
If I then as, "is.matrix(x)", I get TRUE.
However everywhere I've tried to use the matrix returns errors.
Is there a step I'm missing?
Thanks!
-N
2006 Feb 18
3
Bug in Sweave? -- scoping problem? (PR#8615)
I have found a strange scoping problem in Sweave. The following Rnw
file doesn't produce the same output in Sweave as it does if I produce
an R file using Stangle and execute that:
\documentclass[12pt]{article}
\begin{document}
<<R>>=
election <- data.frame(A=1:3, B=9:7, C=rep(0,3))
partytotal <- rep(0, ncol(election))
for (i in 1:ncol(election)) {
partytotal[i] <-
2010 Oct 26
5
cube root of a negative number
Hi,
This might be me missing something painfully obvious but why does the cube root of the following produce an NaN?
> (-4)^(1/3)
[1] NaN
>
As we can see:
> (-1.587401)^3
[1] -4
Thanks!
Greg
2005 Dec 02
3
extracting rows of a dataframe
Hi
look at the following session, in which I have a dataframe,
and I want to extract the second row, without the first column.
Everything works as expected until the last line, where I set
the names of x to NULL, and get a non-desired object (I
want c(4,3).).
Three questions:
(1) why is as.vector(a[2,-1]) not a vector?
(2) How come setting names to NULL gives me bad weirdness?
(3) Can I
2010 Apr 01
2
pdf files in loops
I need to make a bunch of PDF files of histograms. I tried
gatelist = unique(mdf$ArrivalGate)
for( gate in gatelist) {
outfile = paste("../", airport, "/", airport, "taxiHistogram", gate,
".pdf", sep="")
pdf(file = outfile, width = 10, height=8, par(lwd=1))
title=paste("Taxi time for Arrival Gate", gate, "by
2010 Jul 20
1
Call to rgamma using .C causes R to hang
Hi,
I've been trying to get this working for ages, but it causes R to hang.
Here is my C code saved as test1.c
# include <R.h>
# include <Rmath.h>
void test1 (double *x, double *result)
{
result[0] = rgamma(*x, 2.0);
}
This was compiled using R CMD SHLIB test1.c & loaded in R using:
dyn.load("test1.dll")
out <-
2006 Mar 14
1
Internal codes of the factor
Hello!
I am writing some functions and I repeatedly acces internal factor
codes. I figured out that internal codes are 1:n where 1 represents 1st
level, 2 2nd level etc. This is not documented and I wonder if this is
on purpose and subject to change or would be a good idea to add this to
documentation for factor? I can prepair a pacth if this is accepted.
--
Lep pozdrav / With regards,
2006 Apr 17
3
bounding box in PostScript
When a graph is saved as PostScript, the bounding box is often too big.
A consequence is that when the graph is included in a LaTeX document,
the spacing does not look good.
Is this a recognized problem? Is someone working on it? Could I help?
David
2006 Nov 13
1
"stem" does not give a correct answer (PR#9359)
Full_Name: Myung Geun Kim
Version: 2.4.0
OS: Window XP
Submission from: (NULL) (210.110.8.105)
For the data c1 of size 14, stem provides the following result.
**************************************************************
>c1
[1] 14 39 70 11 38 20 37 15 41 74 74 34 48 51
ZZangi>stem(c1)
The decimal point is 1 digit(s) to the right of the |
0 | 145
2 | 04789
4 | 181
6 | 044
2005 Dec 23
1
how to specify dev.print target by a variable?
I want to do the following:
DEVw=500
DEVh=350
fname="my_plot"
dev.print(file=fname, device=FOO, width=DEVw, height=DEVh, bg="transparent")
How do I do this such that I can specify FOO to be one of several choices? (GDD, PNG, postscript, etc.)
If I make FOO a character variable, then "dev.print" complains.
I tried a simpled "substitute" but