similar to: constrOptim for quadratic constraints?

Hi R, A quick question.... How can I optimize the objective function constrained to quadratic constraints? Which function of R is useful for quadratic constraints? Many Thanks, Shubha This e-mail may contain confidential and/or privileged i...{{dropped:13}}

Does anybody know to introduce EQUALITY constraints in 'constrOptim' function? BR, Shubha This e-mail may contain confidential and/or privileged i...{{dropped:13}}

---------- 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

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}}

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

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

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]

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}}

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

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

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?

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

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}}

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 [[alternative HTML version deleted]]

Hi R, Again struck with regular expressions... Suppose, S=c("World_is_beautiful", "one_two_three_four","My_book") I need to extract the last but one element of the strings. So, my output should look like: Ans=c("is","three","My") gsub() can do this...but wondering how do I give the regular expression....

Hi, Can somebody tell me the formula for "?wilderSum" in TTR package? I mean how are these calculated? BR, 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 privileged i...{{dropped:13}}

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

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]]

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

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]]