search for: arows

Dear list, I wonder if there a better way to have rbind/cbind/append to create the first element (if it is empty) instead of doing the following in a loop? for (i in 1:10) { if (i == 1) { aRow = SomeExpression(i) } else { aRow = rbind(aRow,SomeExpression(i)) } } Thanks Anthony

Hi everyone! I have a question about data processing efficiency. My data are as follows: I have a data set on quarterly institutional ownership of equities; some of them have had recent IPOs, some have not (I have a binary flag set). The total dataset size is 700k+ rows. My goal is this: For every quarter since issue for each IPO, I need to find a "matched" firm in the same

...evolution. I got inspired from http://stackoverflow.com/questions/13834364/how-to-get-loop-bounds-in-llvm . However the analysis described there doesn't work well for the second inner loop of thes function below (although if we declare Bcols a short it works well): void MatMul(int Arows, int Acols, int Brows, int Bcols) { short i, j, k; for (i = 0; i < Arows; ++i) { for (j = 0; j < Bcols; ++j) { C[i][j] = 0; for (k = 0; k < Acols; ++k) { C[i][j] += A[i][k] * B[j][k]; } }...

I know this has got to be simple, but I have a added an arrow to a graph with: arrows(5,8,8, predict(lmfit,data.frame(x=8)), length=0.1) but its in the wrong position, correcting it and running again adds an new arrow (which is what you would expect) so how do I a) edit the existing arrow, and b) delete it all together As so often seems to be the case, some of the simplist things seem also to

...w (indeed, I had to resort to writing to file as with a large data set I started running into memory issues if I tried to create the new data frame in memory). Any suggestions on a faster way to achieve what I'm trying to do? #assumes the first data frame above is stored as 'a' arows = (length(a$x)-1) write('', 'temp.txt') for(i in 1:arows){ if(a$time[i+1] > a$time[i]){ write.table(a[i,], 'temp.txt', row.names = F, col.names = F, append = T) x1 = a$time[i] x2 = a$time[i+1] dx = x2-x1 if(dx != 1){ y1 = a$x[i] y2 = a$x[i+1] dy = y2...

I have a 5 column matrix like 12 10 8 6 3 10 9 8 7 5 14 NA 4 NA NA NA 15 NA 10 NA 5 ... I want to select the position of the first entry for each row <=5 for example, for the first row, I want to select the last element and return its position as 5; for th e third row, I want to select the third element and return its position as 3; similarly for the 4th row, I want to select the fifth

I want to take the first row of each unique ID value from a data frame. For instance > ddTable <- data.frame(Id=c(1,1,2,2),name=c("Paul","Joe","Bob","Larry")) I want a dataset that is Id Name 1 Paul 2 Bob > unique(ddTable) Will give me all 4 rows, and > unique(ddTable$Id) Will give me c(1,2), but not accompanied by the name column.

I am new to R, but have been using SAS for years. In this transition period, I am finding myself pulling my hair out to do some of the simplest things. An example of this is that I need to generate a new variable based on the outcome of several existing variables in a data row. In other words, if the variable in all three existing columns are "Yes", then then the new variable should

Hello, I have problems setting up a canon multifunction ir7200. When I print the windows test page, I have something like "smiley" "arrow" "arow" "smiley" "arrow" name_of_the_samba_spool "smileys" driver.dll etc,etc,etc, on a single line. Did somebody used such a multifunction with Samba ? Below is a (long) description of what I did. I

Hi All, I've been having a little trouble with creating a loop that will run a a series of t.tests for inspection, Below is the code i've tried, and some checks i've looked at. I've used the get(paste()) idea as i was told previously that the use of the eval should try and be avoided. I've run a single syntax to check that my systax is correct and works without any problems