Displaying 20 results from an estimated 10000 matches similar to: "ifelse()"
2009 Jan 05
2
prblem with NA
Hi all
I have a data set with the total number of columns =ncol, and the total
number of rows=nrow. I am trying to loop over the values and id the value is
less than or equal to 100 to be changed to 1. if the value is greater than
100 , to be changed to 0. if NA , let X[i,j]=NA. I ran into a problem where
if one row in my data set had all values =NA, then the program does not
continue working
2009 Feb 10
7
How to split a character vector into 3 vectors
Hi ,
Does any one know how to split a character vector , I have a vector X that
looks like this and each row has 3 characters
X
ASK
DGH
ASG
AUJ
FRT
I would like to split the vector into 3 vectors that look like this
X1 X2 X3
A S K
D G H
A S G
A U J
U R T
thanks
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2008 Jun 03
2
merge two data sets
I would like to merge ?data1 ?that contains 100 unique ID?s with another
data set ?data 2? with 150 ID?s and the age of those individuals ( the ID in
data1 is a subset of the ID in data 2) I would like to merge these data1
with data2 and have the result of the merge to have the ID ordered as in
data1.
Can this be done in R?
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2009 Dec 17
3
write.csv and col.names=F
Hi All,
I always have a problem with write.csv when I want the column names to be
ignored, when I specify col.names=F, I get a header of V1 V2 V3 V4 etc.
for example I tried
write.csv(mydata, file="data.csv", quote=FALSE, row.names=F, col.names=F)
Warning message:
In write.csv(mydata, file = "data.csv", quote = FALSE, :
attempt to set 'col.names' ignored
>
2010 Feb 26
6
using grep
Hi All,
I have a character vector with naems of cities in the us. I need to extract
the number that appear after the word "New York", for example,
x<-c("P Los Angeles44AZ", "P New York722AZ", "K New York20")
I want the results to be
722, 20
cab I use the grep function, if so how?
I appreciate your help, thanks,
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2009 Jan 07
3
breaking a loop in R
Hi All,
I was wondering if there is anything that breaks a loop in R. For example,
For (k in 1:100)
For ( i in 1:10){
If ( condition ){
Break the inner loop
}
}
}
In the above case, if the program runs the if statement, then I want the
inner loop for (i in 1:10) to stop looping and skip the rest of the program.
Thanks for your help
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2010 Jan 19
3
problem with the precision of numbers
Hi All,
I was wodering if it is possible to increase the precision using R. I ran
the script below in R and MAPLE and I got different results when k is large.
Any idea how to fix this problem? thanks for your help
for (k in 0:2000){
s=0
for(i in 0:k){
s=s+((-1)^i)*3456*(1+i*1/2000)^3000
}
}
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2010 Jul 29
3
help splitting a data frame
Hi All,
I have a dataset that I would like to split based on : or ? ( the data file
is tab delimited) for example:
Ny:23-45 AC
BA:88-91 DB
KJ:21-13 PA
And I would like the data to be splitted and the final results look like
NY 23 45 AC
BA 88 91 DB
KJ 21 13 PA
I would like to have the resulting data as a data frame so each column is a
variable.
Thanks,
--
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2008 Nov 18
2
counting the number of elements in a column
Hi All,
I have a column that contains values between 0 and 1. I would like to make
a table that consists of the number of elements in each category.
For example , how many elements have values between 0 and 0.1, 0.1 to 0.2,
0.2 to 0.3,etc??..0.9 to 1.
Is there an easy way to do this?
Thanks
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2009 May 27
2
problem with cbind
Hi All,
I have a file with two columns, the first column has the names of the
patients and the second column has the age. I am looking into creating an
output file that looks like
1-10 10-20 etc
Eric Chris
Bob mat
Andrew
Suzan
Where each column has the name of the patients in a given age category that
is displayed in the header. For example in the output, the first
2008 Jun 04
4
merging 3 data sets at once
Hi All,
I am looking into merging 3 data sets I know how to do that by merging data1
with data2 and then merging the result with data 3. I was wondering if it
can be done all at once so I tried,
M<-merge(data1,data2,data3, by=?ID?)
It does not work!
Any ideas?
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Sent from the R help
2008 Apr 10
2
subtract the mean from each column
Hi,
I am new to R an dI need some help
I have a matrix of real values 100*300 and I would like to calculate the
mean for each column , then for each entry in a column i need to subtract
the mean so I will have a matrix where the columns have zero mean. any one
know how to do that . Thanks
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2008 Aug 27
1
How to create additional columns?
I do have some data of dim 100*3 (i.e 100 rows and 3 columns ) stored in a
txt file. I want to read the data into R, Perform the same operation in
each row and store the result in a forth column( that I should create).
I do not know how I can create a forth column to store the result of the
operation for each row?
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2009 Jan 21
3
filling blanks with NA
Hi,
I do have a data set with some missing values that appear as blanks. I want
to fill these blanks with an NA. How can this be done? Thanks for your help
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2009 Oct 06
2
How to extract names from a vector
Hi All,
I have a character vector of length=700. The vector contains names and I
want to extract the names that contain the number 101. The number 101 could
be anywhere within the name.
what is the best way to do this?
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2009 Apr 20
3
Append to a csv file
I am looping over a data set and at each loop I am creating a dataframe
?mydata?
That I wanted to be saves in a .csv file, but I want all the results to be
saved in the same file and this is the way I do it
write.csv(mydata, file= ?data.csv?=F, append=T) . the csv file looks fine
but I always get the following warning message
Warning messages:
1: In write.table(mydata, file =?data.csv?, ... :
2009 Apr 02
1
Updating a data frame
Folks,
Updating values in a table is simple in SAS or SQL, but I've wracked my
brain looking for an elegant solution in R to no avail thus far. Certainly
this is a common need that's been solved in dozens of different ways.
Given an initial dataframe nn and a smaller dataframe of updates uu, I'd
like to replace the values in
nn <- expand.grid('a'=1:4, 'b'=1:3)
2011 Apr 08
3
xyplot, groups and colors
Dear ExpeRts,
I am trying to plot a bunch of growth curves and would like to get
some more control over groups and line colors than I seem to have.
Example:
# make some data
dat <- Orange
dat$group <- ifelse(dat$Tree%in%c('1','4','5'), 'A', 'B')
# plot
xyplot(circumference~age, dat, groups=group)
# now use lines to make the growth curve more
2009 Feb 11
2
Linear model
I want to know how accurate are the p-values when you do linear regression in
R?
I was looking at the variable x3 and the t=10.843 and the corresponding
p-value=2e-16 which is the same p-value for the intercept where the t-value
for the intercept is 48.402.
I tried to calculate the p-value in R and I got 0
x<-2*(1-pt(10.843,2838))
> x
[1] 0
> G<-lm(y~x1+x2+x3+x4+x5)
>
2008 Jun 02
2
merging two data sets with no column header
I have two data sets data1 and data2 with no column names( No header). The
first coluimn in both data sets represents the case ID. How can I tell R to
merge the two data sets by the case ID if there is no header? Also, In data1
I have more cases and I would like the result of the merge to have all the
cases in both data1 and data2. there may be some duplicate cases.
I appreciate if someone can