Displaying 20 results from an estimated 40000 matches similar to: "How to extract names from a vector"
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 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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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
>
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 Feb 10
7
ifelse()
I have a problem with ifelse(), I do not understand how it works.
> X<-c(2,2,1,1,0,0)
> str(X)
num [1:6] 2 2 1 1 0 0
> Y<-ifelse(X>0,1,0)
> Y
[1] 1 1 1 1 0 0
>
Can some one explain what is going on, I do not understand what ifelse is
doing in this case. Can someone explain the output Y.
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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2008 Oct 03
1
Splitting a file into multiple files based on the column name
Hi,
I have a txt file here I want to split it into different files based on the
column name if it contains a specific word or part of a word. For example,
If the header looks like
A001_Sick A015_SB K99_Sick L913_BB
I would like to split the data , one file contains the data with column
names containing the words ?Sick? or ?SB? and have the rest of the data in
another file.
I
2009 Nov 09
6
Find the first values in vector
Hi !
I have a vector:
vec= TRUE TRUE TRUE TRUE FALSE FALSE FALSE FALSE TRUE TRUE FALSE
and I'm looking for a method which let me get only the first values equal
TRUE from this vector. It means that I want to get a vector:
vec_out = TRUE TRUE TRUE TRUE
or posictions values = TRUE: vec_out = 1,2,3,4
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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 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 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)
>
2010 Jan 04
3
Extract vector elements until cumsum <= x
Hi All,
I have a vector n, and for each n[i] I want to extract n[i], n[i+1],
n[i+2]..., until the cumulative sum of n[i] and subsequent elements exceeds
a CheckValue, whereupon I move to the next index and repeat.
I am trying to find a Vectorized approach, and have seen similar posts where
filter{stat} and rollmean{zoo} were suggested, but, I haven't been able to
figure a way to use them