機械学習やってるGIFつくるやつ

svm_animation.R

library(dplyr)
library(ggplot2)

data <- iris %>% filter(Species != "setosa") %>% 
  select(Petal.Width, Sepal.Length, Species) %>%
  sample_frac(1)

ggplot(data, aes(Petal.Width, Sepal.Length)) + 
  geom_point(aes(color = Species), size=4) + xlab("") + ylab("") +
  scale_x_continuous(label=NULL) + 
  scale_y_continuous(label=NULL) + 
  scale_color_discrete(guide = FALSE) +
  theme_bw()

library(animation)

x <- data %>% select(-Species) %>% mutate(c=1) %>% as.matrix
y <- (as.integer(data$Species) - 2.5) * 2
w <- matrix(0, nrow = 3, ncol = 1)

plot_contour <- function(data, w, iter) {
  new_x <- expand.grid(Petal.Width = seq(1.0, 2.5, length.out = 100), 
                       Sepal.Length = seq(4.9, 7.9, length.out = 100), c = 1)
  score <- (as.matrix(new_x) %*% w) %>% scale
  
  df <- new_x %>% mutate(score = score)
  
  ggplot(data, aes(Petal.Width, Sepal.Length)) + 
    geom_point(aes(color = Species), size=5) +
    geom_contour(data = df, aes(Petal.Width, Sepal.Length, z=score), bins = 1, size=2) +
    xlab(NULL) + ylab(NULL) +
    ggtitle(sprintf("iteration: %d", iter)) + 
    scale_x_continuous(label=NULL) + 
    scale_y_continuous(label=NULL) +
    scale_color_discrete(guide = FALSE) + 
    theme_bw()
}

eta <- 0.001
C <- 0.2

pb <- txtProgressBar(max = 25, style = 3L)
animation::saveGIF({
  w <- matrix(0, nrow = 3, ncol = 1)
  for (j in 1:25) {
    setTxtProgressBar(pb, j)
    for (i in seq_len(nrow(x))) {
      if (y[i] * x[i, , drop=FALSE] %*% w <= 1) {
        w2 <- w + eta * y[i] * t(x[i, , drop=FALSE])
      }
      w <- w2 - 2 * eta * C * w
      if (i %% 10 == 0) {
        plot_contour(data, w, (j-1) * 100 + i) %>% print
      }
    }  
  }
  for (k in 1:50) {
    plot_contour(data, w, (j-1) * 100 + i) %>% print
  }
}, interval = 0.1)