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Dear R-Gurus I have a data frame (from CSV file) which has its first column called Date. The Date is in the format mm/dd/yyyy. I was trying to get the weekday for these dates and I tried using wday() and day.of.week() functions and both of them gave me precisely the wrong answers. I think the issue lies in the proper formatting of dates. The class of this column is a factor class and hence I

GuRus How do I use the write function (or write.table or write.csv) to achieve the following please? age=c(32,37,39) names=c("john","peter","jake") I would like create in a directory 3 files each named as john.csv,peter.csv and jake.csv and each file have data from the age vector. That is jon.csv will contain 32, peter.csv will contain 37 and jake.csv will contain

Hello I have a data frame like this: dput(states) structure(list(Date = c("24/07/2012", "25/07/2012", "26/07/2012", "27/07/2012", "28/07/2012", "24/07/2012", "25/07/2012", "26/07/2012", "27/07/2012", "28/07/2012"), State = c(1L, 1L, 1L, 1L, 1L, -1L, -1L, -1L, 1L, -1L)), .Names = c("Date",

Dear guRus Say I have a price vector, P which is P = c(20,50,40,50) for four consecutive days. My initial equity is say $100 and I re-invest the profits made in each transaction so my equity curve increases. If I go Long on day 1, short and short on day 2, long and long on day 3 and finally short on day 4, how do I calculate the total profits using R? Basically I stay invested at all times. I

Hi I wish to read a file from my local directory from inside a function. I am passing the filename as the argument but this does not work. Say for example function(dat) { dat1=read.csv("D:\\dat.csv",header=TRUE) } If I call funtion(dat) I get the following error. 'Intuitively' i understand this is a mistake but how do I overcome this and how can I read a file name passed as an

guRus! I have a function f = exp(x^2-y+(1/z)) Also, x can take values from 1 to 37, y from 2 to 20 and Z from -13 to 51. How can I find the maximum of f using any of the optimization functions please? Is there a way to store the possible values of x, y and Z in a single variable like in a List or in a multi-dimensional array? Thanks for your help Raghu [[alternative HTML version deleted]]

guRus I have say a dataframe, d and I wish to do the following: 1) For each row, I want to take one particular value of the row and multiply it by 2. How do I do it. Say the data frame is as below: OPEN HIGH LOW CLOSE 1931.2 1931.2 1931.2 1931.2 0 0 0 999.05 0 0 0 1052.5 0 0 0 987.8 0 0 0 925.6 0 0 0 866 0 0 0 1400.2 0 0 0 754.5 0 0 0 702.6 0 0 0 653.25 0 0 0 348 0 0 0 801 866.55 866.55