R 使用gganimate指向错误方向的箭头
我有一个简单的情节:R 使用gganimate指向错误方向的箭头,r,gganimate,R,Gganimate,我有一个简单的情节: sample_data <- data.frame( x = 1:100 , y = 1:100 ) temp_plot <- ggplot(sample_data , aes(x = x , y = y)) + geom_line( size = 3 , arrow = arrow() , lineend = "round" ,
sample_data <-
data.frame(
x = 1:100
, y = 1:100
)
temp_plot <-
ggplot(sample_data
, aes(x = x
, y = y)) +
geom_line(
size = 3
, arrow = arrow()
, lineend = "round"
, linejoin = "round"
) +
theme_minimal()
但是,当我这样做时,箭头指向错误的方向,直到最后一帧为止(暂停以明确该点是正确的)
我尝试过使用箭头中的值(包括各种角度,包括负数),但我所做的任何操作似乎都无法纠正箭头的方向(箭头应指向每个帧中的当前向量)
如何使箭头始终指向正确的方向?(我在github目录中交叉发布此信息)。说明
出现这种现象的原因是transition\u显示两个值之间的值,以获得每个帧中的转换位置(箭头所在的位置)。每当计算的过渡位置与数据集上的实际点重合时,同一位置将有两组坐标。这将导致反向箭头
(在您的示例中,箭头一直反向,因为默认帧数与数据中的行数相同,因此每个计算的转换位置都是现有数据点的副本。如果帧数是其他数字,例如137,则箭头将在某些帧中反向并在其他帧中直接指向。)
我们可以用较小的数据集演示这种现象:
p <- ggplot(data.frame(x = 1:4, y = 1:4),
aes(x, y)) +
geom_line(size = 3, arrow = arrow(), lineend = "round", linejoin = "round") +
theme_minimal() +
transition_reveal(x)
animate(p + ggtitle("4 frames"), nframes = 4, fps = 1) # arrow remains reversed till the end
animate(p + ggtitle("10 frames"), nframes = 10, fps = 1) # arrow flips back & forth throughout
我们可以定义一个替代版本的transition\u reveal
,它使用上述内容:
transition_reveal2 <- function (along, range = NULL, keep_last = TRUE) {
along_quo <- enquo(along)
gganimate:::require_quo(along_quo, "along")
ggproto(NULL, TransitionReveal2, # instead of TransitionReveal
params = list(along_quo = along_quo, range = range, keep_last = keep_last))
}
我认为您的示例可能缺少一两行代码,因为我不知道temp\u plot
如何变成temp\u animate
任何地方…谢谢,@Z.Lin。我在复制粘贴的时候错过了。它只是添加了transition\u reveal(x)
,现在是一个问题。我仍然不清楚,当存在重复坐标时,为什么箭头会反转,但知道它是这样就足够了。我将链接到您对我打开的Github问题的回答。也许他们可以在下一次更新中加入您的transition\u reveal
。谢谢箭头反转的原因我也不清楚,但在这一点上,这是一个grid
问题,而不是gganimate
问题,我真的没有做足够的工作来理解前者=P
TransitionReveal2 <- ggproto(
"TransitionReveal2", TransitionReveal,
expand_panel = function (self, data, type, id, match, ease, enter, exit, params,
layer_index) {
row_vars <- self$get_row_vars(data)
if (is.null(row_vars))
return(data)
data$group <- paste0(row_vars$before, row_vars$after)
time <- as.numeric(row_vars$along)
all_frames <- switch(type,
point = tweenr:::tween_along(data, ease, params$nframes,
!!time, group, c(1, params$nframes),
FALSE, params$keep_last),
path = tweenr:::tween_along(data, ease, params$nframes,
!!time, group, c(1, params$nframes),
TRUE, params$keep_last),
polygon = tweenr:::tween_along(data, ease, params$nframes,
!!time, group, c(1, params$nframes),
TRUE, params$keep_last),
stop(type, " layers not currently supported by transition_reveal",
call. = FALSE))
all_frames$group <- paste0(all_frames$group, "<", all_frames$.frame, ">")
all_frames$.frame <- NULL
# added step to filter out transition rows with duplicated positions
all_frames <- all_frames %>%
filter(!(.phase == "transition" &
abs(x - lag(x)) <= sqrt(.Machine$double.eps) &
abs(y - lag(y)) <= sqrt(.Machine$double.eps)))
all_frames
}
)
transition_reveal2 <- function (along, range = NULL, keep_last = TRUE) {
along_quo <- enquo(along)
gganimate:::require_quo(along_quo, "along")
ggproto(NULL, TransitionReveal2, # instead of TransitionReveal
params = list(along_quo = along_quo, range = range, keep_last = keep_last))
}
temp_plot + transition_reveal2(x)