willpearse
commented
7 years ago Looking good Spence. A few pointers:
- Don't do the diamond and then the square step for each sub-matrix within an iteration of the loop. Do the diamond step for all sub-matrices, and then the square step for all the sub-matrices.
- Don't focus on using your 'half' approach. Make a sequence (
seq(1,9,by=8);seq(1,9,by=4); notice a pattern?) and use that to subset by rows and columns.
You're doing very well! Almost there. Remember to take breaks - you're only a few lines from doing this, so don't get "task fixated" and try to see the big picture.
Spencerbrucehudson
Hey Will, I've got the terrain up and running, but am unable to apply it to matrices beyond 5x5.
When I run the following code beyond a those constraints (e.g. 9x9):
diamond.square.step <- function(terrain){ for (i in 2^(n:1)) { half <- i/2 for (c in seq(1, l-1, by=i)) { for (r in seq(1, l-1, by=i)) {
terrain[(1:(r+i)),(1:(c+i))] <- diamond.step(terrain[(1:(r+i)),(1:(c+i))]) terrain[(1:(r+i)),(1:(c+i))] <- square.step(terrain[(1:(r+i)),(1:(c+i))])
terrain[((1+half):(1+i)),(1:(c+half))] <- diamond.step(terrain[((1+half):(1+i)),(1:(c+half))]) terrain[((1+half):(1+i)),(1:(c+half))] <- square.step(terrain[((1+half):(1+i)),(1:(c+half))])
terrain[(1:(r+i)),((1+half):(c+i))] <- diamond.step(terrain[(1:(r+i)),((1+half):(c+i))]) terrain[(1:(r+i)),((1+half):(c+i))] <- square.step(terrain[(1:(r+i)),((1+half):(c+i))])
terrain[((1+half):(r+i)),((1+half):(c+i))] <- diamond.step(terrain[((1+half):(r+i)),((1+half):(c+i))]) terrain[((1+half):(r+i)),((1+half):(c+i))] <- square.step(terrain[((1+half):(r+i)),((1+half):(c+i))]) } } } return(terrain) }
I get this error:
Error in
[<-(*tmp*, h, h, value = 0.4377390625) : subscript out of bounds Called from: diamond.step(terrain[((1 + half):(1 + i)), (1:(c + half))])Any suggestions are much appreciated.
Thanks.