如何使我的密度图从y = 0开始？ 我希望该行从y = 0开始。 这是我使用的代码： ggplot（inrigation_data，aes（x =温度）） + geom_histogram（aes（y = after_stat（密度）），binwidth = 2，fill =“ lightblue＆qu ...

Question

ggplot(irrigation_data, aes(x = Temperature)) +
  geom_histogram(aes(y = after_stat(density)), binwidth = 2, fill = "lightblue") +
  geom_density(color = "blue", size = 1) +
  labs(title = "Soil Temperature Distribution",
       x = "Temperature (°C)",
       y = "Density") +
  theme_minimal()

这是我希望我的直方图/密度图的外观：

可复制的示例：

library(ggplot2)
set.seed(101) 
dd <- data.frame(Temperature = runif(1000, min = 0, max = 45)) 
ggplot(dd, aes(x = Temperature)) + 
    geom_histogram(aes(y = after_stat(density)), binwidth = 2) + 
    geom_density()

通常，我们将内核密度估计限制为某些界限。使用

density

我们可以通过设置

from=

和

to=

Answer 1

> hist(x, freq=FALSE, col='skyblue', border='skyblue')
> 
> density(x) |> lines(col='blue', lty=2)
> density(x, from=0, to=max(x)) |> lines(col='red')
> 
> legend('bottom', col=c('blue', 'red'), lty=2:1, leg=c('normal', 'constrained'))

您可以从[0，y]开始，但是如果有零值接近零，[0，0]可能是没有意义的。

data：

set.seed(42)
x <- runif(1e4, 0, 45)

为了确保直方图以零开始启动，请使用boundary = 0

。我试图使情节尽可能地遵循您的要求，直到颜色和主题。

---

library(ggplot2)
set.seed(101) 
dd <- data.frame(Temperature = runif(1000, min = 0, max = 45)) 

ggplot(dd, aes(x = Temperature)) + 
  geom_histogram(aes(y = after_stat(density), fill = "Histogram"), binwidth = 2, boundary = 0, breaks = seq(0, max(dd$Temperature)+1)) + 
  geom_density(aes(color = "Density"), size = 1, y= "Density",bounds=c(0, max(dd$Temperature))) + 
  labs(title = "Soil Temperature Distribution",
       y = "Density") +
  theme(
    panel.grid = element_blank(),
    plot.title = element_text(hjust = 0.5),
    legend.position = "bottom", 
    axis.line = element_line(),
    panel.background = element_rect(fill="white"),
    panel.border = element_rect(colour = "black", fill=NA, linewidth=1)
  ) +
  scale_fill_manual(values = "#9FC0DC") +
  scale_color_manual(values = "#3A73AF") +
  guides(fill = guide_legend(title = NULL), color = guide_legend(title = NULL))

Answer 2