search for: substraction

Dear all, I have a matrix with data and I want to substract from every value the previous element. Let's assume that my vector(matrix) is c<-(1,2,3,4,5) I want to get remove_previous c<-(0,1,2,3,4). How I can do that efficiently in R? I would like to thank you in advance for your help B.R Alex [[alternative HTML version deleted]]

Hello All, I need help with my dataframe, it is big but here I am using a small table as an example. My dataframe df looks like: X1 X2 X3 1 2011-02 0.00 96.00 2 2011-02 0.00 2.11 3 2011-02 2.00 3.08 4 2011-02 0.06 2.79 5 2011-02 0.00 96.00 6 2011-02 0.00 97.00 7 2011-02 0.08 2.23 I want values in columns X2 and X3 to be checked if they are greater than

Hi all, I'm to inexperienced to come up with the matrix solution elusively appearing on the horizon for the following problem and would appreciate if you could give me a nudge ... I have two vectors a, and b and need to find the closest match for each value of a in b. How to do that efficiently? Thanks, Joh

...(This would probably entail just taking a portion of the matrix.) . This is what the result would be difftype value x1x2 x1x3 x1x4 x1x5 x2x3 x2x4 x2x5 x3x4 x3x5 x4x5 Thank you for any help you can give me. -- View this message in context: http://r.789695.n4.nabble.com/how-to-create-a-substraction-matrix-subtract-a-row-of-every-column-from-the-same-row-in-other-column-tp4642949.html Sent from the R help mailing list archive at Nabble.com.

Dear useRs, I have a matrix with 38 columns and 365 rows. what i want to do is the following..... 1. subtracting from each column, first itself and then all the remaining columns. More precisely, from column number 1, i will first subtract itself(column 1) and then the remaining 37 columns. Afterwards i will take column number 2 and do the same. In this way i want to proceed till 38th column.

Hi all, I want to substract vector B from A's each column... how can R do that smartly without a loop? > A=matrix(c(2:7), 2, 3) > A [,1] [,2] [,3] [1,] 2 4 6 [2,] 3 5 7 > B=matrix(c(1, 2), 2, 1) > B [,1] [1,] 1 [2,] 2 > A-B Error in A - B : non-conformable arrays [[alternative HTML version deleted]]

...column" in my data (see attachment). I suggest it is an artefact (but of what?). Suggestion: I used prcomp this way: prcomp (mat), where mat is a matrix with the column means already substracted followed by a normalisation procedure (see below for details). Is that okay? Or does prcomp repeat substraction steps? Originally my approach was driven by the idea to compute a covariation matrix followed by the use of eigen, but the covariation matrix was to huge to handle. So I switched to prcomp. As I guess that the "columns" in my plots reflect some artefact production I hope to get some hel...

Dear all, I am having a matrix that stores data information in the following format. > roofPart1$TimeStamps[1:5,]      [,1] [,2] [,3] [,4] [,5]   [,6] [1,] 2011    7   21   15   25 20.609 [2,] 2011    7   21   15   25 23.265 [3,] 2011    7   21   15   25 26.000 [4,] 2011    7   21   15   25 28.671 [5,] 2011    7   21   15   25 31.343 I would like to be able to report some simple statistics

Dear list-members, I would like to calculate the difference between two points in time. To convert a 'time (GMT)'-character with the format "1/1/1999 01:01:01" into an object of class "POSIXct"', I first use the strptime() as suggested in the details help(as.POSIXct). e.g. starttime<-strptime("1/1/1999 01:01:01",format="%d/%m/%Y %H:%M:%S")

Hi! I have 2 data.frames: "fish" and "popn": >fish xloc yloc id birth size weight energy gonad 20 15 15 54 -60 107.9 63.0 15952.9 8.0 21 15 15 32 -60 105.1 61.4 15538.8 7.8 91 4 43 96 -60 118.9 69.4 17573.2 8.8 71 32 4 64 -60 121.6 71.0 17976.0 9.0 34 2 64 20 -60 116.2 67.9 17173.0 8.6 95 6 20 58 -60 106.5

I want to find the DOY (Day of Year) of some dates. I think to substract the date 1. January from the data to achive this. Something like: > d <- as.Date("2006-03-13") - as.Date("2006-01-01") +1 > d Time difference of 72 days So far so good. But d is a 'difftime' object. How do I get an Integer value from that? I tried severel things, incuding the

Dear group, Here is my df : df <- structure(list(DESCRIPTION = c("PRM HGH GD ALUMINIUM USD 09/07/10 ", "PRM HGH GD ALUMINIUM USD 09/07/10 ", "PRIMARY NICKEL USD 04/06/10 " ), CREATED.DATE = structure(c(18361, 18361, 18325), class = "Date"), QUANITY = c(-1L, 1L, 1L), CLOSING.PRICE = c("2,415.90", "2,415.90",

In the following code. unsigned char x1 = atoi(argv[1]); unsigned char x2 = atoi(argv[2]); printf("%d\n", x1-x2); The substraction of the last command is translated to the following IR code. %18 = load i8, i8* %6, align 1 %19 = zext i8 %18 to i32 %20 = load i8, i8* %7, align 1 %21 = zext i8 %20 to i32 %22 = sub nsw i32 %19, %21 I don't follow the explanation of nsw in langref. Could anybody help explain what nsw means he...

Hi, Given a date, how do I get the last date of that month? I have data in the form YYYYMM, that I've read as a date using > x$Date <- as.Date(ISOdate(substr(x$YearEnd,1,4),substr(x$YearEnd,5,6),1)) But this gives the first day of the month. To get the last day of the month, I tried > as.Date(as.yearmon(x$Date,frac=0)) But I don't get the last day of the month here. (Tried

Dear R-experts, Here below my R code working with quite a few warnings.? x11 and x12 are dichotomous variable (0=no and 1=yes). I substract 1 to ignore intercept. I would like not to ignore intercept. How to modify my R code because if I just remove -1 it does not work? y= c(32,45,65,34,23,43,65,76,87,98,7,867,56,45,65,76,88,34,55,66) x11=c(0,1,1,0,0,1,1,1,0,0,1,0,0,1,0,0,1,1,0,1)

Hi everybody How do I do to calculate the median and average of a colum of time data like this: "8:50:10". I also need to plot the time difference between two colums Thanks a lot -- View this message in context: http://n4.nabble.com/median-for-time-data-tp932287p932287.html Sent from the R help mailing list archive at Nabble.com.

Hi, I have this data.frame with two variables in it, > z V1 V2 1 10 8 2 NA 18 3 9 7 4 3 NA 5 NA 10 6 11 12 7 13 9 8 12 11 and a vector of means, > means <- apply(z, 2, function (col) mean(na.omit(col))) > means V1 V2 9.666667 10.714286 My intention was substracting means from z, so instictively I tried > z-means V1 V2 1 0.3333333

Hello everybody, I'm a newbie in R and just went through an introduction class recently. Here's my problem. I have 2 text files (.txt) with plain numbers ('doubles' for those who know c++) ordered into 2 columns as below: coordinate1 value1 coordinate2 value2 coordinate3 value3 ... ... coordinateN valueN I would like to write a small programme in which i would: 1. take

For the simple C program below I show the output of clang and the output of the VS compiler (I am on windows). Maybe this is obvious to you, but is it really faster to do 2 multiplications, 3 movl instructions, 2 shifts, 1 add, and 1 substract than to do 1 mov, 1 cdq, and 1 idiv? I run into this while trying to understand why my code runs slower with llvm than a comparable program on windows.

*This message was transferred with a trial version of CommuniGate(tm) Pro* A simple question, perhaps to simple, but I am new to R: For a data frame with k variables and n1+n2 observations (two groups) how can i substract the group means for every variable, so both group variables become centered to mean zero? Thanks in advance for your help H?ctor