R hist() 函数 - 绘制直方图
R 语言实例R hist() 函数用于绘制直方图，展示数据的分布情况。
直方图将数据分成若干个区间（bin），显示每个区间内数据的频数或频率。
hist() 函数语法格式如下：
hist(x, breaks = "Sturges", freq = NULL, col = NULL,
main = paste("Histogram of", xname))
参数说明：
x 数值向量。
breaks 区间划分方式：可以是数字（区间个数）、向量（断点位置）或算法名。
freq 是否显示频数（TRUE）或密度（FALSE）。
实例
# 生成考试成绩数据
set.seed(123)
scores <- rnorm(200, mean = 70, sd = 10)
# 绘制直方图
hist(scores,
main = "考试成绩分布",
xlab = "分数",
ylab = "频数",
col = "skyblue",
border = "white",
breaks = 15)
# 添加均值和中位数线
abline(v = mean(scores), col = "red", lwd = 2, lty = 2)
abline(v = median(scores), col = "blue", lwd = 2, lty = 3)
legend("topright",
legend = c("均值", "中位数"),
col = c("red", "blue"), lty = c(2, 3), lwd = 2)
set.seed(123)
scores <- rnorm(200, mean = 70, sd = 10)
# 绘制直方图
hist(scores,
main = "考试成绩分布",
xlab = "分数",
ylab = "频数",
col = "skyblue",
border = "white",
breaks = 15)
# 添加均值和中位数线
abline(v = mean(scores), col = "red", lwd = 2, lty = 2)
abline(v = median(scores), col = "blue", lwd = 2, lty = 3)
legend("topright",
legend = c("均值", "中位数"),
col = c("red", "blue"), lty = c(2, 3), lwd = 2)
执行以上代码会显示直方图，包含红色均值线和蓝色中位数线。