Displaying 20 results from an estimated 4000 matches similar to: "Symbolic references - passing variable names into functions"
2004 Nov 23
5
number of pairwise present data in matrix with missings
is there a smart way of determining the number of pairwise present data
in a data matrix with missings (maybe as a by-product of some
statistical function?)
so far, i used several loops like:
for (column1 in 1:99) {
for (column2 in 2:100) {
for (row in 1:500) {
if (!is.na(matrix[row,column1]) & !is.na(matrix[row,column2])) {
pairs[col1,col2] <- pairs[col1,col2]+1
2012 Jun 12
4
How to index a matrix with different row-number for each column?
here's my question: suppose I have a matrix:
mt<-matrix(1:12,ncol=6)
now I have a vector
vt<-c(1,2,2,2,1,2)
which means I want to get:
the 1st row for column1;
the 2nd row for column2;
the 2nd row for column3;
the 2nd row for column4;
...
that what I want is this vector:
1,4,6,8,9,12
Does anyone know how to do this fast?
I know I can use for-loop to travel all columns,but
2012 Mar 07
2
dot products
Hello,
I need to take a dot product of each row of a dataframe and a vector.
The number of columns will be dynamic. The way I've been doing it so
far is contorted. Is there a better way?
dotproduct <- function(dataf, v2) {
apply(t(t(as.matrix(a)) * v2),1,sum) #contorted!
}
df = data.frame(a=c(1,2,3),b=c(4,5,6))
vec = c(4,5)
dotproduct(df, vec)
thanks,
2009 Aug 03
2
Some SQL Challenges
Hi,
Im trying to complete a list of jobs using SQL Querries and some "if else"
commands but im stucked in some steps. Could any of you give me some help?
-in COLUMN1 change the format 20JAN2000:00:00:00 to 20JAN2000 and exclude
every row that date is different from 20.
-extract the first character in COLUMN2 and creat COLUMN3 with that value
ex:
COL2,COL3
135,1
461,4
247,2
-in every
2007 Oct 19
1
conduct pairwise column comparisons without comparing a column to itself
# Hello
# I have a question regarding pairwise calculations of a matrix using a
"for-loop."
# Below I have a matrix "X" with 8 columns. These are genotypic data so
Column1 & Column2 is
# a unit, Column3 & Column4 is a unit, Column5 & Column6 is a unit, and
Coulmn7 & 8 is a unit.
# I have a loop designed to calculate the number of times an individual in
2010 May 31
2
accessing a data frame with row names
Readers,
I have entered a file into r:
,column1,column2
row1,0.1,0.2
row2,0.3,0.4
using the command:
dataframe<-read.table("/path/to/file.csv",header=T,row.names=1)
When I try the command:
dataframe[,2]
I receive the response:
NULL
I was expecting:
row1 0.2
row2 0.4
What is my error with the syntax please?
Yours,
r251
mandriva2009
2009 May 14
2
Function to read a string as the variables as opposed to taking the string name as the variable
I am writing a custom function that uses an R-function from the
reshape package: cast. However, my question could be applicable to
any R function.
Normally one writes the arguments directly into a function, e.g.:
result=cast(table1, column1 + column2 + column3 ~ column4,
mean) (1)
I need to be able to write this statement as follows:
result=cast(table1, string_with_columns ~
2008 Feb 26
1
Split data.frames depeding values of a column
Hello to all
is there a function wich splits a data.frame (column1,column2,column3,....)
into
data1 <-(column1,column3....) #column2 = 1
data2 <-(column1,column3....) #column2 = 2
data3 <-(column1,column3....) #column2 = 3
...
Regards Knut
2006 Jun 07
4
Question: coding protected methods
Apologies first, because I need to ramp up on Ruby and coding Ruby in Rails,
however it''s my 3rd day with this beast :) so I''m asking :
When I added protected methods to the model before it was like:
protected
method....................
end
Would this be a valid way to write a protected method as well ?:
attr_protected :column1, :column2
Perhaps this particular call
2009 Jun 17
6
script help
Hi
?
I have a file. list.txt (two columns)
?
column1??? column2
name??????? address
?
?
I need to put in the letter file letter.txt eg:
?
Dear: Chloe
Address: CA
?
Can I use this
?
for i `cat list.txt` | sed 's/Chloe/$i.1; /CA/$i.2/g' $i.letter.txt
?
Thank you for your help
?
?
?
?
?
__________________________________________________________________
Looking for the perfect gift?
2009 Jun 15
2
Help with syntax error
Hi,
I have written boxplot commands of this form before, but I don''t quite understand why the function call is reporting a syntax error in this instance. All parameters passed to the function are strings.
Thanks in advance.
Payam
> simplevar <- function(wframe,column1,column2) {
+ tframe <- get(wframe)
+ x1 <- which(names(wframe)==column1)
+ x2 <-
2013 Mar 21
2
Displaying median value over the horizontal(median)line in the boxplot
Hi,
set.seed(45)
test1<-data.frame(columnA=rnorm(7,45),columnB=rnorm(7,10)) #used an example probably similar to your actual data
apply(test1,2,function(x) sprintf("%.1f",median(x)))
#columnA columnB
# "44.5"? "10.2"
par(mfrow=c(1,2))
lapply(test1,function(x) {b<-
2004 Oct 25
2
Reading sections of data files based on pattern matching
I am about to write general functions to read the output of simulations
models.
These model generate output files with different sections which I want
to analyze plot etc.
Since this will be used many people at the department I wanted to make
sure that will do this in the best way.
For instance I want to read a snippets of data from a text that look
like this.
2009 Dec 03
2
Dataframe help
Hi there
I have two dataframes
Dataframe_1
column_1 colum_2
121 12345
145 1675
167 2765
Dataframe_2
column_1 column2
121 abc
345 lmn
167 efg
I want a resulting dataframe
121 12345 abc
167 2765 efg
how do i go abt it
Ramya
--
View this message in context: http://n4.nabble.com/Dataframe-help-tp947934p947934.html
Sent from the R
2010 Feb 27
1
New Variable from Several Existing Variables
I am new to R, but have been using SAS for years. In this transition period,
I am finding myself pulling my hair out to do some of the simplest things.
An example of this is that I need to generate a new variable based on the
outcome of several existing variables in a data row. In other words, if the
variable in all three existing columns are "Yes", then then the new variable
should
2009 Nov 26
3
barchart() {Lattice} help.
Hi R Users,
I'm trying to plot a stacked barplot. Here is data:
Sample Col1 Col2 Col3
Row1 -2 4 -1
Row2 3 -2 4
Row3 3 5 -2
Row4 4 1 -1
I'm using following R code:
library(lattice)
dta<-read.table("data.txt", header=TRUE, row.names="Sample")
barchart(data.matrix(dta),
horizontal=FALSE,
stack=TRUE,
col=2:4,
2003 Aug 07
2
Question about 'NA'
Hi all,
Ive got a database with 10 columns (different
variables) for 100 subjects, each column with
different # of NA's. I'd like to know if it is
possible to use a function to exclude the NA's using
only a specific column, lets say:
Data2 <- omit.exclude(Data1$column1) ??, then
Data3 <- omit.exclude(Data1$column2) and so on
I tried the code above but with no results
Thanks
2009 Jul 07
2
How to separate the string?
Hi everyone,
Hi want to separate the string(column1) for example
column1 column2 column3 column4 column5 column6
bear b e a r
cat c a t
tiger t i g e r
I know how to do this in excel where using MID function.
Now I want to solve it using R. The list of strings is in
2011 Apr 13
2
setting pairwise comparisons of columns
Hi,
I have a number of genes (columns) for which I want to examine pairwise
associations of genotypes (each row is an individual)...For example (see
data below), I would like to compare M1 to M2, M2 to M3, and M1 to M3 (i.e.
does ac from M1 tend to be found with bc from M2 more often than expected.)
Down stream I will be performing chi square tests for each pair.
But I am looking for a way to
2006 Jan 04
3
matrix math
I am using R 2.1.1 in an windows XP environment.
I have 2 dataframes, temp1 and temp2.
Each dataframe has 20 variables (“cocolumns") and 525 observations (“rows”). All variables are numeric.
I want to create a new dataframe that also has 20 columns and 525 rows. The values in this dataframe should be the sum of the 2 other dataframe.
(i.e. temp1$column