Displaying 20 results from an estimated 11000 matches similar to: "define variables from rows of a matrix"
2011 Aug 13
2
define variables from a matrix
I have a following matrix and wish to define a variable based the variable
A=matrix(0,5,5)
A[1,]=c(30,20,100,120,90)
A[2,]=c(40,30,20,50,100)
A[3,]=c(50,50,40,30,30)
A[4,]=c(30,20,40,50,50)
A[5,]=c(30,50,NA,NA,100)
> A
[,1] [,2] [,3] [,4] [,5]
[1,] 30 20 100 120 90
[2,] 40 30 20 50 100
[3,] 50 50 40 30 30
[4,] 30 20 40 50 50
[5,] 30 50 NA NA
2005 Feb 21
5
Compare rows of two matrices
Hello,
#I have two matrices, eg.:
y <- matrix( c(20, NA, NA, 45, 50, 19, 32, 101, 10, 22, NA, NA, 80, 49, 61, 190), ncol=4 )
x <- matrix( c(20, NA, NA, NA, 50, 19, 32, 101, 10, 22, NA, NA, 80, 49, 61, 190), ncol=4 )
#Whereas x contains all NA?s from y plus some additional NA?s.
#I want to find the index of these additional NA?s. I think, there must be a very
2007 Mar 08
2
Removing duplicated rows within a matrix, with missing data as wildcards
I'd like to remove duplicated rows within a matrix, with missing data
being treated as wildcards.
For example
> x <- matrix((1:3), 5, 3)
> x[4,2] = NA
> x[3,3] = NA
> x
[,1] [,2] [,3]
[1,] 1 3 2
[2,] 2 1 3
[3,] 3 2 NA
[4,] 1 NA 2
[5,] 2 1 3
I would like to obtain
[,1] [,2] [,3]
[1,] 1 3 2
[2,] 2 1 3
2017 Dec 20
2
outlining (highlighting) pixels in ggplot2
Using the small reproducible example below, I'd like to know if one can
somehow use the matrix "sig" (defined below) to add a black outline (with
lwd=2) to all pixels with a corresponding value of 1 in the matrix 'sig'?
So for example, in the ggplot2 plot below, the pixel located at [1,3] would
be outlined by a black square since the value at sig[1,3] == 1. This is my
first
2011 Apr 28
2
changing a specific column name
Hi,
Can someone please tell me how to change the column name of a specific
column. How do I change the name of the column 'Species'?
Thanks in advance
d <- iris
colnames(d)
[1] "Sepal.Length" "Sepal.Width" "Petal.Length" "Petal.Width" "Species"
ind <- which(names(d)=='Species')
ind
[1] 5
colnames(d[ind])
[1]
2008 Jul 27
4
product of successive rows
Hi everyone,
I want to perform an operation on a matrx that outputs the product of
successive pairs of rows. For example: calculating the product between rows
1 & 2; 3 & 4; 5 & 6...etc.
Does anyone know of any readily available functions that can do this?
Thanks,
rcoder
--
View this message in context: http://www.nabble.com/product-of-successive-rows-tp18681259p18681259.html
2003 Feb 10
1
Zero rows/cols in the hessian matrix
Dear R experts!
I try to minimize a function with external C fitting function.
I get the hessian matrix. Here it is:
[,1] [,2] [,3] [,4]
[1,] 1.8816631 0 0.8859803 0
[2,] 0.0000000 0 0.0000000 0
[3,] 0.8859803 0 0.4859983 0
[4,] 0.0000000 0 0.0000000 0
Second and fourth rows/columns have zero values only. That's OK,
because that ones related
2005 Feb 07
4
proportional matrix rows
Hi
I have a two-column integer matrix like this:
R> jj
[,1] [,2]
[1,] -1 1
[2,] -2 2
[3,] -7 6
[4,] -8 7
[5,] -6 5
[6,] -9 8
[7,] -5 4
[8,] 3 -3
[9,] -10 9
[10,] -4 3
I want a diagnostic that detects whether a row is a multiple of
the first row or not. In this case, this would be rows 1,2, and 8.
How to do this
2013 Jun 10
1
modify and append new rows to a data.frame using ddply
Hi,
I have a data.frame that contains a variable act which records the duration (in seconds) of two states (wet-dry) for several individuals (identified by Ring) over a period of time. Since I want to work with daytime (i.e. from sunrise till sunset) and night time (i.e. from sunset till next sunrise), I have to split act from time[i] till sunset and from sunset until time[i+1], and from time[k]
2008 Sep 17
1
Re adout row and column of a matrix value
Hello R users,
I want to readout the row and column postion from a certain matrix value
into a csv file.
I have only found this syntax
"which(a == b, arr.ind = T)"
so I get
a = matrix
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,] 1 1 2 2 2 1 1 2
[2,] 1 2 3 3 3 4 4 3
[3,] 3 3 3 5 5 6 5 4
[4,] 4 4 4 3
2012 Apr 06
3
filling the matrix row by row in the order from lower to larger elements
Hello, everybody!
I have a matrix "input" (see example below) - with all unique entries
that are actually unique ranks (i.e., start with 1, no ties).
I want to assign a value of 100 to the first row of the column that
contains the minimum (i.e., value of 1).
Then, I want to assign a value of 100 to the second row of the column
that contains the value of 2, etc.
The results I am looking
2013 Jun 08
0
modify and append new rows in a dataframe
My data frame shows changes on the variable act which records the consecutive duration (in seconds) of two states (wet-dry) over a few days for several?individuals (identified by Ring). Since I want to work with daytime (i.e. from dawn till dusk) and night time (i.e. from dusk till next dawn), I have to split act in two: from time[i] till dusk and from dusk until time[i+1], and from time[k] till
2010 Apr 23
3
reordering of matrix rows to maximize the sum of the diagonal
Hi r-help community,
This question isn't so much a syntax/coding one, but here goes:
Let's say I have matrix of arbitrary dimensions and I'd like to
reorder the rows in such a way that I could maximize the sum of the
entries along the diagonal.
For example, for this 3x3 matrix:
[,1] [,2] [,3]
[1,] 3 4 13
[2,] 9 1 2
[3,] 2 11 1
rearranging the rows
2010 Sep 06
3
Aggregate certain rows in a matrix
Hi,
I have a matrix that looks like this
a <- c(1,1,1,1,2,2,3,3,3,3)
b <- c(2,2,2,3,4,4,4,5,5,6)
c <- c(1,2,3,4,5,6,7,8,9,10)
M <- matrix(nr=10,nc=3)
M[,1] <- a
M[,2] <- b
M[,3] <- c
> M
[,1] [,2] [,3]
[1,] 1 2 1
[2,] 1 2 2
[3,] 1 2 3
[4,] 1 3 4
[5,] 2 4 5
[6,] 2 4 6
[7,] 3 4 7
2011 Feb 10
3
Permuting rows of a matrix
Hi,
I need to permute the rows of a matrix, where each row is independently rearranged. A simple solution is this:
shuffled <- datamatrix <- matrix(1:24, ncol = 4)
for (i in 1:nrow(datamatrix)) { shuffled[i, ] <- sample(datamatrix[i, ]) }
> datamatrix
[,1] [,2] [,3] [,4]
[1,] 1 7 13 19
[2,] 2 8 14 20
[3,] 3 9 15 21
[4,] 4 10 16 22
[5,]
2012 May 25
1
Correlograms: using boxes and different variables on rows and columns
I'm trying to make correlograms using corrgram. See below for a simple
example.
####
library(corrgram)
data(baseball)
vars1 <- c("Assists","Atbat","Errors","Hits","Homer","logSal")
vars2 <- c("Putouts","RBI","Runs","Walks","Years")
2013 Jun 26
3
match rows of R
Hi all,
What would be an efficient way to match rows of a matrix to a vector?
ex:
m<-matrix(1:9, nrow=3)
m [,1] [,2] [,3]
[1,] 1 4 7
[2,] 2 5 8
[3,] 3 6 9
#################################
which(m==c(2,5,8)) # I want this to return 2
######################
Thanks,
Sachin
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2018 Feb 28
1
Missed opportunity in the midend, unsigned comparison
Hi everybody, I see a missed optimization opportunity in LLVM that GCC
catches and I'd love to hear community's input.
Here's the original C code:
1 char arr[2];
2 char *get(unsigned ind) {
3 if (ind >= 1) {
4 return 0;
5 }
6 return &(arr[ind]);
7 }
The variable `ind` is unsigned so, based on the comparison, if it is not
greater or equals to one, than it is
2008 Feb 11
4
Conditional rows
Hi,
Given a simple example, test <- matrix(c(0.1, 0.2, 0.1, 0.2, 0.1, 0.1, 0.3,
0.1, 0.1), 3, 3)
How to generate row indexes for which their corresponding row values are
less than or equal to 0.2 ? For this example, row 2 and 3 are the correct
ones.
Thanks
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2006 Nov 19
4
The most common row in a matrix?
Hi,
How do you get the most common row from a matrix? If I have a matrix
like this
array(1:3,dim=c(4,5))
[,1] [,2] [,3] [,4] [,5]
[1,] 1 2 3 1 2
[2,] 2 3 1 2 3
[3,] 3 1 2 3 1
[4,] 1 2 3 1 2
in which rows 1 and 4 are similar, I want to find that vector c
(1,2,3,1,2).
Atte Tenkanen
University of Turku, Finland