R:堆叠面积图不堆叠

Question

我有数据，我想把它画成一个堆叠的区域图。在x轴上，我有连续的数据，在y轴上，我有连续的数据，准备累积。这是我对一些虚拟数据使用的代码：

library(data.table)
library(ggplot2)

set.seed(1)
dt <- data.table(var=sample(1:6,1000,replace=TRUE),xdata=runif(1000),ydata=runif(1000))
setorder(dt, var, xdata)

dt$cumydata <- dt[,
                  cumsum(ydata),
                  by = .(var)]$V1/sum(dt$ydata)

ggplot(dt, aes(x = xdata, y = cumydata, fill = as.factor(var))) +
  geom_area(position = "stack")

这是输出图：

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我的问题是，数据不能正确地堆叠。我想这可能是因为数据的连续性？

Answer 1

根据Jimbou的信息，我终于解决了这个问题。这只是一些预处理。我还把整件事做了对数。

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library(data.table)
library(ggplot2)

set.seed(1)
dtt <- data.table(var=sample(1:6,1000,replace=TRUE),xdata=runif(1000),ydata=runif(1000))

setorder(dtt, var, xdata)

log.min.xdata <- log(min(dtt$xdata))
log.max.xdata <- log(max(dtt$xdata))

nbreaks <- 101

temp <- hist(log(dtt$xdata[dtt$var==1]),
             breaks = seq(log.min.xdata, log.max.xdata, length=nbreaks),
             plot = FALSE)


dt <- data.table(var = unlist(lapply(sort(unique(dtt$var)),
                                     function(x){rep(x,nbreaks-1)})),
                 bin = rep(1:(nbreaks-1),length(unique(dtt$var))),
                 mid = rep(temp$mids))

dt$count <- dt[,
               hist(log(dtt$xdata[dtt$var==var]), 
                    breaks = seq(log.min.xdata, log.max.xdata, length=nbreaks),
                    plot = FALSE)$counts,
               by = .(var)]$V1

dt$cumcount <- dt[,
                  cumsum(count),
                  by = .(var)]$V1



pp <- ggplot(dt, aes(x = exp(mid), y = cumcount, fill = as.factor(var))) +
  geom_area(position = "stack") +
  scale_x_log10() +
  theme_bw() +
  theme(legend.position = c(0.1, 0.70),
        legend.background = element_rect(fill="lightgrey", 
                                         size=0.5, linetype="solid")) +
  labs(title = "y",
       fill = " var",
       x = "xdata",
       y = "cumcount") +
  theme(title = element_text(face = "bold"),
        axis.title = element_text(face = "bold"),
        legend.title = element_text(face = "bold"),
        legend.text = element_text(face = "bold"))

Answer 2

对于堆叠面积图，x值和发生次数必须相同。因此，将样本数据更改为此将给出预期的输出：

set.seed(1)
dt <- data.table(ydata=runif(1002))
dt$var <- rep(1:6, each=167)
dt$xdata <- rep(runif(167), 6)
setorder(dt, var, xdata)

dt$cumydata <- dt[,
                  cumsum(ydata),
                  by = .(var)]$V1/sum(dt$ydata)

ggplot(dt,aes(x = xdata, y = cumydata, fill = as.factor(var))) +
  geom_area(position = "stack")

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