懐かしのライフゲーム

昔，BASIC で組んで喜んでいたものだ

10分ほどで組んで，チューニング

for を使っているけど，速すぎる。

ただ，図を描くのは一気呵成でないといけないので，rect で引数にベクトルを与えた。

life <- function(xy, step = 100, nrow = 100, ncol = nrow, sleep = 0) {
    a <- matrix(0, nrow, ncol)
    a[xy] <- 1
    nrow1 <- nrow - 1
    ncol1 <- ncol - 1
    old <- par(mar = c(0, 0, 0, 0))
    for (l in seq_len(step)) {
        b <- a
        plot(1, 1, type = "n", xlim = c(1, nrow), ylim = c(1, ncol), bty = "n", axes = FALSE, xlab = "", ylab = "")
        i0 <- j0 <- numeric(nrow * ncol)
        n <- 0
        for (i in 2:nrow1) {
            for (j in 2:ncol1) {
                if (a[i, j] == 0 && sum(a[(i - 1):(i + 1), (j - 1):(j + 1)]) == 3) {
                  b[i, j] <- 1
                } else if (a[i, j] == 1 && (sum(a[(i - 1):(i + 1), (j - 1):(j + 1)]) <= 2 || sum(a[(i - 1):(i + 1), (j -
                  1):(j + 1)]) >= 5)) {
                  b[i, j] <- 0
                }
                if (b[i, j]) {
                  n <- n + 1
                  i0[n] <- i
                  j0[n] <- j
                }
            }
        }
        i0 <- i0[1:n]
        j0 <- j0[1:n]
        rect(i0 - 0.5, j0 - 0.5, i0 + 0.5, j0 + 0.5, col = "red", border = "red")
        Sys.sleep(sleep)
        a <- b
    }
    par(old)
}
x <- rbind(cbind(rep(49, 11), 45:55), cbind(rep(50, 11), 45:55), cbind(rep(51, 11), 45:55))
life(x, step = 25)
x <- cbind(sample(100, 5000, replace = TRUE), sample(100, 5000, replace = TRUE))
life(x, step = 400)
x <- matrix(c(18, 11, 18, 29, 18, 30, 18, 31, 19, 12, 19, 29, 20, 10, 20, 11, 20, 12, 20, 31), byrow = TRUE, ncol = 2)
life(x + 30, step = 200)