Question

我想使用晶格封装生成一个等值线图，其中y轴从顶部开始并向下移动（即顶部的最小值，底部的最大值）。如果我更改以下内容：

contourplot(Male ~ Age * Year, data=this.ds)

到

contourplot(Male ~ Age * rev(Year), data=this.ds)

然后正确绘制图形，但y轴刻度标记不反转。（即仍然从底部开始并转到顶部。） - （参见完整可重复示例的消息末尾。）

我认为答案涉及使用'scale'列表对象（所以我认为这有一个单行解决方案）但我不确定它是什么。

非常感谢，Jon

完全可重复的例子：

library(lattice)
attach(environmental)
ozo.m <- loess((ozone^(1/3)) ~ wind * temperature * radiation,
           parametric = c("radiation", "wind"), span = 1, degree = 2)
w.marginal <- seq(min(wind), max(wind), length.out = 50)
t.marginal <- seq(min(temperature), max(temperature), length.out = 50)
r.marginal <- seq(min(radiation), max(radiation), length.out = 4) 
wtr.marginal <- list(wind = w.marginal, temperature = t.marginal,
                              radiation = r.marginal) 
grid <- expand.grid(wtr.marginal) 
grid[, "fit"] <- c(predict(ozo.m, grid))

照常绘图：

contourplot(fit ~ wind * temperature, data = grid,
              cuts = 10, region = TRUE,
              xlab = "Wind Speed (mph)",
              ylab = "Temperature (F)",
              main = "Cube Root Ozone (cube root ppb)")

对温度使用rev（）函数：

contourplot(fit ~ wind * rev(temperature), data = grid,
            cuts = 10, region = TRUE,
            xlab = "Wind Speed (mph)",
            ylab = "Temperature (F)",
            main = "Cube Root Ozone (cube root ppb)")

detach()

我想这样，y（温度）轴标签反转以及y轴值。（即它读取90,80,70,60从下到上而不是60,70,80,90）

Answer 1

您可以尝试在labels参数中反转y轴的scales。

library(lattice)
contourplot(fit ~ wind * rev(temperature), data = grid,
            cuts = 10, region = TRUE,
            xlab = "Wind Speed (mph)",
            ylab = "Temperature (F)",
            main = "Cube Root Ozone (cube root ppb)",
            scales = list(y = list(
              labels = seq(from = 100, to = 60, by = -10))))

说实话，我认为seq(from = 90, to = 60, by = -10)应该有用，但它会给标签80, 70, 60, NA。

Answer 2

更清洁的解决方案是颠倒指定y轴限制的长度为二的向量的顺序。设置ylim=rev(range(temperature))的效果非常好，但是对于更精确匹配原始布局的绘图，您可能希望使用extendrange()来绘制更大的范围。

## OP's example figure
a <- contourplot(fit ~ wind * temperature, data = grid,
                 cuts = 10, region = TRUE,
                 xlab = "Wind Speed (mph)",
                 ylab = "Temperature (F)",
                 main = "Cube Root Ozone (cube root ppb)")

## Same figure with the y-axis reversed 
b <- update(a, ylim = rev(extendrange(temperature, f=0.01)))

## Plot figs side-by-side to check that that worked
library(gridExtra)
grid.arrange(a, b, ncol=2)

（虽然我在上面使用了update()来添加修改后的ylim，但也可以在contourplot的原始调用中提供它。我只是这样做了我想直接比较原始图和修改图。）

如何使用莱迪思包在等高线图中反转Y轴

2 个答案: