similar to: Differentiation

Displaying 20 results from an estimated 2000 matches similar to: "Differentiation"

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 This e-mail may contain confidential and/or privileged i...{{dropped:13}}
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 This e-mail may contain confidential and/or privileged i...{{dropped:13}}
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
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 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 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 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 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 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 This e-mail may contain confidential and/or privileged i...{{dropped:13}}
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
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 [[alternative HTML version deleted]]
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
2008 Jan 26
1
Any numeric differentiation routine in R for boundary points?
Hi, I have a scalar valued function with several variables. One of the variables is restricted to be non-negative. For example, f(x,y)=sqrt(x)*exp(y), then x should be non-negative. I need the gradient and hessian for some vector (0,y), i.e., I need the gradient and hessian at the boudary of parameter space. The "numderiv" package does not work, even for f(x)=sqrt(x), if you do
2008 Jun 04
4
sum of unknown number of matrices
Hi R, I have a list of matrices. I need to get the sum of all the matrices in the list. Example: a=b=c=d=matrix(1:4,2,2) l=list(a,b,c,d) I need: > a+b+c+d [,1] [,2] [1,] 4 12 [2,] 8 16 Something like do.call("+",l) is not working...why is this? I may not be knowing the number of matrices in the list... Thanks, Shubha This e-mail
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
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
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 This e-mail may contain confidential and/or
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
2007 Jan 30
2
R packages
Hi, Do any body know which packages of R I need to go for the below topics? 1. Monte Carlo Markov chain (MCMC) 2. Gibbs Sampling 3. Metropolis Hastings Thanks in advance... Shubha [[alternative HTML version deleted]]
2007 Jan 23
4
Vector to Matrix transformation
Hi R, I have a vector V1 of unknown length, say n. I need to convert this into a matrix C of row size=5, and accordingly the column should be updated. I tried with: C=as.matrix(V1,5,n/5) But it is not working...Could somebody help me on this? Thanks in advance... [[alternative HTML version deleted]]