Question

如何将颜色的逻辑'slope > 0'转换为更复杂的条件？

如果斜率> 0，则为红线。如果斜率== 0，则为蓝线。如果斜率<0，则为黑线。

# setup
library(dplyr)
library(ggplot2)
library(lazyeval)
set.seed(205)
dat = data.frame(t=rep(1:2, each=10), 
                 pairs=rep(1:10,2), 
                 value=rnorm(20))
dat$value[dat$pairs==1] <- 1 # forgot to set one pair to slope==0


# function
plotFun <- function(df, groupBy, dv, time) {
  ggplot(df %>% group_by_(groupBy) %>%
           mutate_(slope = interp(~(dv2[time2==2] - dv2[time2==1])/(2-1),
                                  dv2=as.name(dv), 
                                  time2=as.name(time))),
         aes_string(time, dv, group = groupBy, 
                    colour = 'slope > 0')) +
    scale_colour_manual(values=c("red", "black")) +
    geom_point() +
    geom_line() +
    stat_summary(fun.y=mean,geom="line",lwd=2,aes(group=1))
}

# plot
plotFun(dat, "pairs", "value", "t")

Answer 1

我不确定为什么要为此制作单独的功能。我会这样做

aggregate(Names ~ Category, data=df, FUN=function(x) length(unique(x)))
  Category Names
1        0     2
2        1     1

我已经为斜率添加了一列，根据成对分组的值计算并使用ggplot中的group-method。颜色的条件我在线条的审美。因为if-statements因为原始的图例标题太长了所以我把它关掉了。

希望有所帮助。

Answer 2

@ lukeA的评论对我有用：

# setup
library(dplyr)
library(ggplot2)
library(lazyeval)
set.seed(205)
dat = data.frame(t=rep(1:2, each=10), 
                 pairs=rep(1:10,2), 
                 value=rnorm(20))
dat$value[dat$pairs==1] <- 1 # forgot to set one pair to slope==0


# function
plotFun <- function(df, groupBy, dv, time) {
  ggplot(df %>% group_by_(groupBy) %>%
           mutate_(slope = interp(~(dv2[time2==2] - dv2[time2==1])/(2-1),
                                  dv2=as.name(dv), 
                                  time2=as.name(time))),
         aes_string(time, dv, group = groupBy, 
                    colour = ifelse(slope>0,"blue",         
                             ifelse(slope==0,"black","red"))) +
    scale_color_identity() +
    geom_point() +
    geom_line() +
    stat_summary(fun.y=mean,geom="line",lwd=2,aes(group=1))
}

# plot
plotFun(dat, "pairs", "value", "t")

在aes_string中使用ifelse来着色

2 个答案: