多个 gganimate 图堆叠和并排

Question

我有四个具有相同帧数的动画图，其中我想要三个堆叠的动画和三个堆叠动画右侧的第四个。通常我会使用类似 grid.arrange 的东西，但这似乎不适用于 gganimate。

我根据这里的代码得到了以下代码：https : //github.com/thomasp85/gganimate/wiki/Animation-Composition

a_mgif <- image_read(a_gif)
b_mgif <- image_read(b_gif)
c_mgif <- image_read(c_gif)
d_mgif <- image_read(d_gif)

new_gif <- image_append(c(a_mgif[1], b_mgif[1], c_mgif[1], d_mgif[1]), stack = TRUE)

for(i in 2:100){
  combined <- image_append(c(a_mgif[i], b_mgif[i], c_mgif[i], d_mgif[i]), stack = TRUE)
  new_gif <- c(new_gif, combined)
}

magick::image_write(new_gif, path="animation.1.gif")

这工作正常并产生四个堆叠的动画图。我尝试将其修改为在前三个堆叠图右侧的第四个图，如下所示：

new_gif.1 <- image_append(c(a_mgif[1], b_mgif[1], c_mgif[1]), stack = TRUE)
new_gif.2 <- image_append(c(new_gif.1, d_mgif[1]), stack = FALSE)

for(i in 2:100){
  combined.1 <- image_append(c(a_mgif[i], b_mgif[i], c_mgif[i]), stack = TRUE)
  combined.2 <- image_append(c(combined.1, d_mgif[i]), stack = FALSE)
  new_gif.2 <- c(new_gif.2,combined.2)
}

magick::image_write(new_gif.2, path="animation.2.gif")

这似乎有效，直到写入文件为止。写文件需要很长时间，我让它运行了几个小时，它仍然没有完成，而第一个版本的所有文件都在一分钟内写入，所以很明显有问题。这两个示例中的数据/图完全相同。关于这里出了什么问题的任何想法？

Answer 1

对我有用的是将image_append调用包装到image_flatten. 我还首先将 img1 和 img4 水平组合，然后将其与 img2 和 img3 堆叠在一起。

在这里我只回收了示例中的两个动画，但是这个解决方案也应该使用四个独立的动画 - 至少对我来说，在带有 ImageMagick 6.9.10.23 和 magick_2.3 的 R4.0 上，虽然它需要大约 3 分钟，也许 630 MB 的临时存储空间：

library(dplyr)
library(ggplot2)
library(magick)
library(gganimate)

A <- rnorm(100,50,10)
B <- rnorm(100,50,10)
DV <- c(A,B)
IV <- rep(c("A","B"), each=100)
sims <- rep(rep(1:10, each=10), 2)
df <- data.frame(sims, IV, DV)

means_df <- df %>%
    group_by(sims,IV) %>%
    summarize(means=mean(DV),
              sem = sd(DV)/sqrt(length(DV)))

stats_df <- df %>%
    group_by(sims) %>%
    summarize(ts = t.test(DV~IV,var.equal=TRUE)$statistic)

a <- ggplot(means_df, aes(x = IV,y = means, fill = IV)) +
    geom_bar(stat = "identity") +
    geom_point(aes(x = IV, y = DV), data = df, alpha = .25) +
    geom_errorbar(aes(ymin = means - sem, ymax = means + sem), width = .2) +
    theme_classic() +
    transition_states(
        states = sims,
        transition_length = 2,
        state_length = 1
    ) + 
    enter_fade() + 
    exit_shrink() +
    ease_aes('sine-in-out')

a_gif <- animate(a, width = 240, height = 240, renderer = magick_renderer())

b <- ggplot(stats_df, aes(x = ts))+
    geom_vline(aes(xintercept = ts, frame = sims))+
    geom_line(aes(x=x,y=y),
              data = data.frame(x = seq(-5,5, .1),
                                y = dt(seq(-5,5, .1), df = 18))) +
    theme_classic() +
    ylab("density") +
    xlab("t value") +
    transition_states(
        states = sims,
        transition_length = 2,
        state_length = 1
    ) +
    enter_fade() + 
    exit_shrink() +
    ease_aes('sine-in-out')

b_gif <- animate(b, width = 240, height = 240, renderer = magick_renderer())

c_gif <- animate(b, width = 240, height = 240, renderer = magick_renderer())
d_gif <- animate(a, width = 240, height = 240, renderer = magick_renderer())

i=1
combined <- image_append(c(a_gif[i], d_gif[i]))
new_gif <- image_append(c(image_flatten(combined),
                          b_gif[i], c_gif[i]), stack=TRUE)

for(i in 2:100){
    combined <- image_append(c(a_gif[i], d_gif[i]))
    fullcombined <- image_append(c(image_flatten(combined), 
                                   b_gif[i], c_gif[i]), stack=TRUE)
    new_gif <- c(new_gif, fullcombined)
}

image_write(new_gif, format="gif", path="animation.2.gif")

编辑：替代 或者，您可以使用cowplot来排列绘图并在循环中生成单个帧，然后用于gifski制作动画；这在图像放置方面更加灵活，因为您可以添加坐标draw_image（参见相应cowplot示例）。下面是一个简单的网格示例：

library(dplyr)
library(ggplot2)
library(magick)
library(gganimate)
library(cowplot)
library(gifski)

A <- rnorm(100,50,10)
B <- rnorm(100,50,10)
DV <- c(A,B)
IV <- rep(c("A","B"), each=100)
sims <- rep(rep(1:10, each=10), 2)
df <- data.frame(sims, IV, DV)

means_df <- df %>%
    group_by(sims,IV) %>%
    summarize(means=mean(DV),
              sem = sd(DV)/sqrt(length(DV)))

stats_df <- df %>%
    group_by(sims) %>%
    summarize(ts = t.test(DV~IV,var.equal=TRUE)$statistic)

a <- ggplot(means_df, aes(x = IV,y = means, fill = IV)) +
    geom_bar(stat = "identity") +
    geom_point(aes(x = IV, y = DV), data = df, alpha = .25) +
    geom_errorbar(aes(ymin = means - sem, ymax = means + sem), width = .2) +
    theme_classic() +
    transition_states(
        states = sims,
        transition_length = 2,
        state_length = 1
    ) + 
    enter_fade() + 
    exit_shrink() +
    ease_aes('sine-in-out')

a_gif <- animate(a, width = 240, height = 240, renderer = magick_renderer())

b <- ggplot(stats_df, aes(x = ts))+
    geom_vline(aes(xintercept = ts, frame = sims))+
    geom_line(aes(x=x,y=y),
              data = data.frame(x = seq(-5,5, .1),
                                y = dt(seq(-5,5, .1), df = 18))) +
    theme_classic() +
    ylab("density") +
    xlab("t value") +
    transition_states(
        states = sims,
        transition_length = 2,
        state_length = 1
    ) +
    enter_fade() + 
    exit_shrink() +
    ease_aes('sine-in-out')

b_gif <- animate(b, width = 240, height = 240, renderer = magick_renderer())

c_gif <- animate(b, width = 240, height = 240, renderer = magick_renderer())
d_gif <- animate(a, width = 240, height = 240, renderer = magick_renderer())

tdir <- tempdir()
for(i in 1:100){
    new_gif <- plot_grid(ggdraw() + draw_image(a_gif[i], scale = 0.9), 
                         ggdraw() + draw_image(d_gif[i], scale = 0.9),
                         ggdraw() + draw_image(b_gif[i], scale = 0.9),
                         ggdraw(),
                         ggdraw() + draw_image(c_gif[i], scale = 0.9),
                         ncol=2)
    ggsave(
        filename = file.path(tdir, paste0("out_", sprintf("%03d", i), ".png")),
        plot = new_gif, width = 2.4, height = 3.6, device = "png")
}

png_files <- sort(list.files(path = tdir, pattern = "out_", full.names = TRUE))
gifski(png_files, gif_file = "out.gif", width = 480, height = 720, delay = .1,
       progress = TRUE)

编辑 #2（2021 年 5 月）：

自从我最初的回答以来发生了一些变化，并且正如@agbarnett 指出的那样，渲染器现在必须renderer = magick_renderer()在所有animate命令中显式设置为。