Displaying 20 results from an estimated 4000 matches similar to: "sum of unknown number of matrices"
2008 Jul 08
8
Sum(Random Numbers)=100
Hi R,
I need to generate 50 random numbers (preferably poisson), such that
their sum is equal to 100. How do I do this?
Thank you,
Shubha
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2008 Jul 23
18
Simple... but...
Hi R,
If
x=c(1,3,5)
y=c(2,4,6)
I need a vector which is c(1,2,3,4,5,6) from x and y.
How do I do it? I mean the best way....
Thanks, Shubha
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2008 Jul 23
8
sequential sum of a vector...
Hi R,
Let,
x=1:80
I want to sum up first 8 elements of x, then again next 8 elements of x,
then again another 8 elements..... So, my new vector should look like:
c(36,100,164,228,292,356,420,484,548,612)
I used:
aggregate(x,list(rep(1:10,each=8)),sum)[-1]
or
rowsum(x,group=rep(1:10,each=8))
But without grouping, can I achieve the required? Any other ways of
doing
2008 May 15
1
apply function
Hi R,
Getting a strange result using ?apply. Please look into the below codes:
>
d=data.frame(a=c(1,2,3),b=c("A","B","C"),c=c(TRUE,FALSE,FALSE),d=c(T,F,F
))
> class(d[,1])
[1] "numeric"
> class(d[,2])
[1] "factor"
> class(d[,3])
[1] "logical"
> class(d[,4])
[1] "logical"
>
2007 Feb 13
5
Fatigued R
Hi R,
Please solve my problem...........
I am extracting Bloomberg data from R, in a loop. R is getting fatigued
by doing this process and gives some errors. I introduced sleep
function. Doing this sometimes I get the results and sometimes not. I
even noticed that if I give complete rest for R (don't open R window)
for 1 day and then run my code with the sleep function, then the
2008 Apr 09
11
Number of words in a string
Hi R,
A quick question: How do we find the number of words in a string?
Example:
C="Have a nice day"
And the number of words should be 4. any built in function or?...
Thanks, Shubha
Shubha Karanth | Amba Research
Ph +91 80 3980 8031 | Mob +91 94 4886 4510
Bangalore * Colombo * London * New York * San José * Singapore * www.ambaresearch.com
This e-mail may contain
2008 May 06
2
To preserve the class "Matrix"
Hi,
Suppose
a=matrix(1:9,3,3)
> a
[,1] [,2] [,3]
[1,] 1 4 7
[2,] 2 5 8
[3,] 3 6 9
Now,
> class(a[1:2,])
[1] "matrix"
> class(a[1:3,])
[1] "matrix"
> class(a[,1:2])
[1] "matrix"
> class(a[,1:3])
[1] "matrix"
But,
> class(a[1,])
[1] "integer"
> class(a[,1])
[1]
2008 Sep 29
3
Cross-tabulation Question
Hi R,
This is a cross tabulation question. Suppose that,
> d=read.table("clipboard",header=F)
> d
V1 V2 V3
A One Apple
A One Cake
A One Cake
B One Apple
B One Apple
B One Apple
> table(d$V2,d$V3)
Apple Cake
One 4 2
But, I don't want the count to be like the above. Here, it is counting
the
2008 Mar 25
3
Dimensions of a List
Hi R,
I have a list,
l=list(list(c(1,2),c(4,5),c(6,7)),list(c(11,22,33),c(44,55,66)))
> l
[[1]]
[[1]][[1]]
[1] 1 2
[[1]][[2]]
[1] 4 5
[[1]][[3]]
[1] 6 7
[[2]]
[[2]][[1]]
[1] 11 22 33
[[2]][[2]]
[1] 44 55 66
How do I know the dimensions of this list?... In other words, how many
sub-lists, sub-sub-lists etc...are there in l? How do I know this?
2008 Jun 09
3
Overlaying the matrices
Hi R,
I have a matrix,
> x1=matrix(NA,6,6,dimnames=list(letters[1:6],LETTERS[1:6]))
> x1
A B C D E F
a NA NA NA NA NA NA
b NA NA NA NA NA NA
c NA NA NA NA NA NA
d NA NA NA NA NA NA
e NA NA NA NA NA NA
f NA NA NA NA NA NA
> x2=matrix(rpois(9,1),3,3,dimnames=list(c("b","a","f"),c("D","E","F")))
> x2
2008 Aug 07
3
Downloading Yahoo data
Hi R,
I am trying to download the data from R. I give the below command.
> library(fImport)
> yahooSeries("IBM")
trying URL
'http://chart.yahoo.com/table.csv?s=IBM&a=7&b=08&c=2007&d=7&e=07&f=2008&
g=d&x=.csv'
Error in download.file(url = url, destfile = file, method = method) :
cannot open URL
2008 Aug 12
7
Between the values
Hi R,
This is a very trivial one....
C=0.1
I want to check whether my value of C is between 0 and 1 exclusively....
I don't want to use (C>0 & C<1). And I can't use a single statement like
(0<C<1). Is there a between function? Or how do we specify from 0 to 1?
Does %in% help me?
Many Thanks,
Shubha
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2008 Feb 14
3
Transposing by a group variable
Hi R,
Can I transpose a data frame by a particular group variable?
For example:
d=data.frame(group=c(1,1,2,2,2),val=c(6,4,6,3,5))
And my output should be:
data.frame(group=c(1,2),v1=c(6,6),v2=c(4,3),v3=c(NA,5))
Many thanks,
Shubha
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2007 Aug 20
3
Differentiation
Hi,
Could anyone tell me what is the command used in R to do
1. Differentiation
2. Newton Raphson method (Numerical Analysis in general...)
Are there any packages separately for this?
Thanks for your help!
BR, Shubha
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2010 Jun 17
3
R user interface
Hi R,
I have a an excel file with a lot of data. I need to create an user
interface in R, which has one single screen. It needs to contain a right
pane containing the click buttons for different countries (say). If the
user clicks a country, then a chart needs to be created for that
country, taking the data from Excel. Is this possible and which package
helps me in doing this? Many thanks in
2006 Dec 02
4
Fwd: Urgent Help in Paste Command
Hi Experts,
I want to see my object as below:
'C:\Program Files\R\R-2.4.0\bin\Rgui.exe'
So I use the paste command. None of the below is working. Could anyone help
me on this?
> paste("'C:\Program Files\R\R-2.4.0\bin\Rgui.exe'")
[1] "'C:Program FilesRR-2.4.0\binRgui.exe'"
> paste("'C:","\","Program
2007 Aug 29
5
Month end calculations
Hi R users,
Is there a function in R, which does some calculation only for the month
end in a daily data?... In other words, is there a command in R,
equivalent to "last." function in SAS?
BR, Shubha
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2007 May 18
3
ordering in list.files
Hi R,
My csv files are stored in the order, '1abc.csv', '2def.csv',
'3ghi.csv', '10files.csv' in a folder. When I read this into R from
list.files (R command: x=list.files("Z:/CSV/fold",full.names=F), I don't
get the same order, instead I get the order as "10files.csv" "1abc.csv"
"2def.csv" "3ghi.csv". But
2006 Nov 24
1
Fwd: Dates Conversion/write.foreign
---------- Forwarded message ----------
From: Shubha Vishwanath Karanth <shubhak at ambaresearch.com>
Date: Nov 24, 2006 7:54 PM
Subject: Dates Conversion/write.foreign
To: Shubha Karanth <shubhakaranth at gmail.com>, Shubha Vishwanath
Karanth <shubhak at ambaresearch.com>
Hi R experts,
I need an urgent help...
I have an a dataframe caled idat. Below i give a snapshot
2008 Jun 19
2
Comparison between R and MATLAB
Hi R,
Can I get a comparison between R and MATLAB? How is R efficient than MATLAB? Or what are the weaknesses of R compared to MATLAB?
Thank you very much for your help,
Shubha
Shubha Karanth | Amba Research
Ph +91 80 3980 8031 | Mob +91 94 4886 4510
Bangalore * Colombo * London * New York * San José * Singapore * www.ambaresearch.com
This e-mail may contain confidential and/or