Displaying 20 results from an estimated 6000 matches similar to: "Reshaping data"
2005 Jan 21
6
Avoiding a Loop?
Dear R-Helpers,
I have a matrix where the first column is known. The second column is
the result of multiplying this first column with a constant "const". The
third column is the result of multiplying the second column with
"const".....
So far, I did it like this (as a simplified example):
nr.of.columns <- 4
myconstant <- 27.5
mymatrix <- matrix(numeric(0), nrow=5,
2007 Jan 29
1
"Reversal" of Aggregation
Dear all,
given I have a data.frame in a format like this
mydf <- data.frame(age=rep(1:3,5),
year=c(rep(1996,3), rep(1997,3), rep(1998,3),
rep(1999,3), rep(2000,3)),
income=1:15)
mydf
Now I convert it to some 2D-frequency table like this:
mymatrix <- tapply(X=mydf$income, INDEX=list(mydf$age, mydf$year),
2005 Feb 03
2
Surprising Behavior of 'tapply'
Dear all,
I wanted to make a two-way-table of two variables with a counting
variable stored in another column of a dataframe. In version 1.9.1, the
behavior is as expected as shown in the simplified example code.
> sex <- rep(c("F", "M"), 5)
> income <- c(rep("low", 5), rep("high", 5))
> count <- 1:10
> mydf <-
2005 Feb 21
3
Sorting a matrix on two columns
Hello,
If a matrix with 5 columns has been defined and the first two columns
need to be sorted in ascending order, how can this be achieved whilst
ensuring the
other 3 columns data are in relative position to the sorted columns?
Glen Jones
[[alternative HTML version deleted]]
2005 Aug 17
2
power of a matrix
Dear all,
I have a population with three age-classes, at time t=0 the population
is:
n.zero <- c(1,0,0)
I have a transition matrix A which denotes "fertility" and "survival":
A <- matrix(c(0,1,5, 0.3,0,0, 0,0.5,0), ncol=3, byrow=TRUE)
To obtain the population at t=1, I calculate:
A %*% n.zero
To obtain the population t=2, I calculate:
A %*% (A %*% n.zero)
... and so
2005 Sep 19
6
Teaching R - In front of the computer?
Dear R-Users,
given you have been teaching R to students (grad level, mainly social
science background, no previous programming experience, 80% know SPSS),
what are your experiences concerning the style of teaching? Do you
prefer to stand in front of the class like in "normal" lectures and you
show them slides? Or do you you explain some concept (for example things
like
2006 Jul 14
2
References verifying accuracy of R for basic statisticalcalculations and tests
Hi,
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Corey Powell
>
> Do you know of any references that verify the accuracy of R
> for basic statistical calculations and tests. The results of
> these studies should indicate that R results are the same as
> the results of other statistical packages to a certain number
> of decimal places on some benchmark
2010 Nov 03
2
avoiding too many loops - reshaping data
Hello!
I have a data frame like this one:
mydf<-data.frame(city=c("a","a","a","a","a","a","a","a","b","b","b","b","b","b","b","b"),
2018 Feb 25
0
reshaping column items into rows per unique ID
Hi Allaisone,
If you want a data frame as the output you will have to put up with a
few NA values unless each Customer has the same number of diet types:
a1df<-read.table(text="CustomerID DietType
1 a
1 c
1 b
2 f
2 a
3 j
4
2018 Feb 25
0
reshaping column items into rows per unique ID
I believe you need to spend time with an R tutorial or two: a data frame
(presumably the "table" data structure you describe) can *not* contain
"blanks" -- all columns must be the same length, which means NA's are
filled in as needed.
Also, 8e^5 * 7e^4 = 5.6e^10, which almost certainly will not fit into any
local version of R (maybe it would in some server version --
2018 Feb 25
4
reshaping column items into rows per unique ID
Hi All
I have a datafram which looks like this :
CustomerID DietType
1 a
1 c
1 b
2 f
2 a
3 j
4 c
4 c
4 f
And I would like to reshape this so I can
2005 Nov 23
2
Dancing lissajous
We can't post images here so I've put up a web page to show off a neat
little animation in R:
http://www.geocities.com/robsteele/
Adios!
2003 Oct 09
4
Previous Commands
Dear All,
yesterday I took the R-1.8.0-source file and compiled it on my own. As I am
using Linux just for a couple of weeks, it was my first compiling session
with ./configure, make, ....
Everything went fine, except for one thing: if I want to look at the
commands history by using the cursor keys, it does not work. Instead of
displaying the previous commands, it returns something like
2005 May 22
2
Maps, Eastern Europe
Dear all,
I would like to employ a European map in a presentation. My idea was to
use:
library(mapdata)
map("worldHires", c("Austria", "Switzerland", "Germany"))
where I include all countries from my analysis as a vector of character
strings like in the example above. Unfortunately, I was unable to
specify the Baltic States (Latvia, Lithuania, Estonia) or
2004 Jun 09
2
moving data and output?
Hello,
I have a few questions now:
1. How can I move data the following way:
I have 2 variables:
one two
1 5 ^
3 4 |
1 3 |
4 4 |
Now I want to move the two one arround (sorry I don't know how to say
that in english). That means: I want to move the first item at the
end of my column and move the second at the first place, the third at
the second, and so on. You can see it at
2004 Jul 22
3
Replace only Capital Letters
Dear All,
I have these data:
exampledata <- c("This is one item", "This is Another One", "And so is
This")
I would like to find each occurence of a blank space followed by a Capital
Letter and replace it by a blank space, a left curly brace, the respective
Capital Letter, and then a right curly brace.
I thought the following will do:
gsub(pattern = "
2009 Jul 20
1
S4 method dispatch with inheritance
Hi,
I'm trying to create a new S4 class (myMatrix) which for now just
extends dgCMatrix (from package Matrix). Then I want to use "[" which is
defined in Matrix.
Out of the box with "[" (defined in Matrix) I lose the class information
and the result is an object of class dgCMatrix. If I specify a
"["-method for myMatrix, it is not used because a signature
2012 Aug 01
1
Error message: $ operator is invalid for atomic vectors
HI,
The code was working perfectly fine yesterday and today, until half an hour ago.? Couldn't find any problems in the code. Still, I am getting error message.
myMatrix <- data.matrix(read.table(text="
Name??????????? Age
ANTONY??????? 27
IMRAN????????? 30
RAJ????????????????? 22
NAHAS????????? 32
GEO??????????????? 42
", header=TRUE))
MinMaxArray? <- data.frame(MIN =
2009 Jan 18
8
regex -> negate a word
Dear all,
let's assume I have a vector of character strings:
x <- c("abcdef", "defabc", "qwerty")
What I would like to find is the following: all elements where the word
'abc' does not appear (i.e. 3 in this case of 'x').
Since I am not really experienced with regular expressions, I started
slowly and thought I find all word were
2005 Aug 08
2
computationally singular
Hi,
I have a dataset which has around 138 variables and 30,000 cases. I am
trying to calculate a mahalanobis distance matrix for them and my
procedure is like this:
Suppose my data is stored in mymatrix
> S<-cov(mymatrix) # this is fine
> D<-sapply(1:nrow(mymatrix), function(i) mahalanobis(mymatrix, mymatrix[i,], S))
Error in solve.default(cov, ...) : system is computationally