search for: cellwise

...cast(A1, comp~val~year) I would now like to look for changes from one year to the other, i.e. "for(i in levels(A$year)) A2[,,i]-A2[,,i-1]" and put that into A3. Which should work except for the first one, i.e. giving me a 3*3*2 object A3. The more abstract formulation would possibly be cellwise operation within adjacent matrices of the array. I have however searched the forum for the key words and there is not much. Any help even in form of a reference would be appreciated. -- View this message in context: http://www.nabble.com/Subtract-matrices-within-arrays-along-indices-tp24717178p24...