search for: andria

I need help with (hopefully) just one more thing. I have been fussing with this for quite some time and have decided just to give up and ask! I want to match a column in a matrix to a vector. I found a "which" command that I thought would be helpful as it does the following: > g=c(1,5,3,2,7) > which(g==5) [1] 2 As the above gave which placement in the g vector corresponded to

I need help determining the unique columns of a matrix and the numbers of each unique column. For example, let's say I have a matrix with 6 columns, 2 of these are filled with the value of 1 and the other 4 are filled with the value of 0. I would then like to have a command that tells me what the unique columns are (so columns with 1s and columns with 0s) and the number of each type of

To clear up a question regarding my earlier posting regarding random changes in a vector: Say you have a vector (1, -1, -1, 1, 1, -1). I want each value in the vector to have a probability that it will change signs when this vector is regenerated. For example, probability = 50%. When the vector is regenerated, the first value in the vector (1) has a 50% chance of switching to -1. If I