如何在ggplot2中绘制加权黄土平滑?

时间:2014-02-24 18:52:40

标签: r ggplot2 smooth loess

如何添加将另一列视为权重的黄土平滑?

假设我有以下data.frame:

    library(ggplot2)

    df <- data.frame(x=seq(1:21))
    df$y <- df$x*0.3 + 10
    df$weight <- 10

    df[6,] <- c(6, 0.1, 1)
    df[7,] <- c(7, 0.1, 1)

    df[13,] <- c(13, 0.1, 1)
    df[14,] <- c(14, 0.1, 1)

    df[20,] <- c(20, 0.1, 1)
    df[21,] <- c(21, 0.1, 1)

    ggplot(data=df, aes(x=x, y=y, size=weight)) + geom_point() + geom_smooth(method=loess, legend=FALSE)

绘制黄土平滑线会产生以下结果:

loess-smoothing without weights

但是我想使用柱重,这样黄土就像每个重量为10的点都是10次一样:

    df2 <- subset(df, !(x %in% c(6,7,13,14,20,21)))
    df2$weight <- 1

    df3 <- df2
    for(i in seq(1:9)){
      df3 <- rbind(df3, df2)
    }
    df3 <- rbind(df3, c(6, 0.1, 1))
    df3 <- rbind(df3, c(7, 0.1, 1))

    df3 <- rbind(df3, c(13, 0.1, 1))
    df3 <- rbind(df3, c(14, 0.1, 1))

    df3 <- rbind(df3, c(20, 0.1, 1))
    df3 <- rbind(df3, c(21, 0.1, 1))

    ggplot(data=df3, aes(x=x, y=y)) + geom_point() + geom_smooth(method=loess, legend=FALSE) 
    # or to demonstrate
    ggplot(data=df3, aes(x=x, y=y)) + geom_jitter() + geom_smooth(method=loess, legend=FALSE)

smoothing with weights

我找到了黄土功能的参数权重。但我不知道如何从geom_smooth()调用它。

1 个答案:

答案 0 :(得分:11)

我想我只需要为aes添加另一个参数:

  ggplot(data=df, aes(x=x, y=y, size=weight, weight=weight)) + geom_point() + geom_smooth(method=loess, legend=FALSE)

enter image description here