使用 ggplot2 模拟 Google Sheets 平滑折线图答案

【问题标题】：Emulating Google Sheets smoothed line chart with ggplot2使用 ggplot2 模拟 Google Sheets 平滑折线图
【发布时间】：2018-12-22 15:32:59
【问题描述】：

我正在尝试使用 ggplot2 模拟 Google 表格平滑折线图。它通过所有数据点绘制一条平滑线。

在 Google 表格中绘制：上面和下面的行是我的硬编码置信区间。

数据：

library(tidyverse)
data <- tibble(
    date = seq.Date(as.Date("2018-12-01"), as.Date("2018-12-20"), by = "days"),
    var = c(0.329,0.348,0.349,0.355,0.382,0.363,0.340,0.359,0.336,0.358,0.398,0.389,0.389,0.390,0.383,0.343,0.352,0.415,0.397,0.430),
    lower = c(0.311,0.330,0.330,0.336,0.364,0.345,0.321,0.342,0.319,0.341,0.384,0.375,0.375,0.374,0.369,0.329,0.337,0.400,0.382,0.417),
    upper = c(0.347,0.366,0.368,0.374,0.400,0.381,0.358,0.377,0.354,0.375,0.413,0.404,0.403,0.405,0.397,0.357,0.368,0.430,0.412,0.444))

我几乎得到与黄土相同的曲线。但它在某些时候给了我一个警告和一个奇怪的锐利区域。

代码：

ggplot(data, aes(x = seq_along(date), y = var)) + 
    geom_point(size = 2, color = "blue", alpha = 0.2) +
    # geom_smooth(method = "lm", formula = y ~ splines::bs(x, 20), se = F) +
    # stat_smooth(method = "gam", formula = y ~ s(x, k = 19), se = F) +
    stat_smooth(method = "loess", span = 0.2, se = F) +
    theme_classic() + theme(axis.line = element_line(size = 0.5, colour = "grey80"))

警告：

Warning messages:
1: In simpleLoess(y, x, w, span, degree = degree, parametric = parametric,  :
    Chernobyl! trL>n 20
2: In simpleLoess(y, x, w, span, degree = degree, parametric = parametric,  :
    Chernobyl! trL>n 20
3: In sqrt(sum.squares/one.delta) : NaNs produced

R 图：

【问题讨论】：

不是相当重复，但这应该会有所帮助：stackoverflow.com/q/35205795/5325862 Google Sheets 可能在幕后做 LOESS，而是用其他方法计算点之间的平滑曲线

标签： r ggplot2 loess

【解决方案1】：

只是为了可视化，您可以尝试 @hrbrmstr 提供的很棒的 ggalt 包。

ggalt::geom_xspline 绘制 x 样条线。

library(ggalt)
library(tidyverse)

data <- tibble(
    date = seq.Date(as.Date("2018-12-01"), as.Date("2018-12-20"), by = "days"),
    var = c(0.329,0.348,0.349,0.355,0.382,0.363,0.340,0.359,0.336,0.358,0.398,0.389,0.389,0.390,0.383,0.343,0.352,0.415,0.397,0.430),
    lower = c(0.311,0.330,0.330,0.336,0.364,0.345,0.321,0.342,0.319,0.341,0.384,0.375,0.375,0.374,0.369,0.329,0.337,0.400,0.382,0.417),
    upper = c(0.347,0.366,0.368,0.374,0.400,0.381,0.358,0.377,0.354,0.375,0.413,0.404,0.403,0.405,0.397,0.357,0.368,0.430,0.412,0.444))

ggplot(data, aes(seq_along(date), var)) + 
    geom_point(size = 2, color = "blue", alpha = 0.2) +
    geom_xspline() +
    theme_classic() + 
    theme(axis.line = element_line(size = 0.5, colour = "grey80"))

【讨论】：