ggplot 的用户输入名称

Question

我正在编写一个函数来为用户绘制热图。在以下示例中，它绘制了不同性别的成绩随时间的变化。

但是，这是一种特殊情况。 “性别”可能有其他名称，如“类”。 我会让用户输入他们的具体名称，然后让 ggplot 为每个轴设置正确的标签。

如何根据需要修改函数“heatmap()”？

sampledata <- matrix(c(1:60,1:60,rep(0:1,each=60),sample(1:3,120,replace = T)),ncol=3)
colnames(sampledata) <- c("Time","Gender","Grade")
sampledata <- data.frame(sampledata)
heatmap=function(sampledata,Gender)
{
sampledata$Time <- factor(sampledata$Time)
sampledata$Grade <- factor(sampledata$Grade)
sampledata$Gender <- factor(sampledata$Gender)
color_palette <- colorRampPalette(c("#31a354","#2c7fb8", "#fcbfb8","#f03b20"))(length((levels(factor(sampledata$Grade)))))
ggplot(data = sampledata) + geom_tile( aes(x = Time, y = Gender, fill = Grade))+scale_x_discrete(breaks = c("10","20","30","40","50"))+scale_fill_manual(values =color_palette,labels=c("0-1","1-2","2-3","3-4","4-5","5-6",">6"))+  theme_bw()+scale_y_discrete(labels=c("Female","Male"))
}

Answer 1

最简单的解决方案是使用 aes_string 重新定义函数。 调用该函数时，您需要将列的名称传递给它 您想用作字符串。

heatmap=function(sampledata,y)
{
        sampledata$Time <- factor(sampledata$Time)
        sampledata$Grade <- factor(sampledata$Grade)
        sampledata$new_var <- factor(sampledata[,y])
        color_palette <- colorRampPalette(c("#31a354","#2c7fb8", "#fcbfb8","#f03b20"))(length((levels(factor(sampledata$Grade)))))
        ggplot(data = sampledata) + geom_tile( aes_string(x = "Time", y = "new_var", fill = "Grade"))+scale_x_discrete(breaks = c("10","20","30","40","50"))+scale_fill_manual(values =color_palette,labels=c("0-1","1-2","2-3","3-4","4-5","5-6",">6"))+  theme_bw()+scale_y_discrete(labels=c("Female","Male")) + ylab(y)
}


# Below an example of how you call the newly defined function
heatmap(sampledata, "Gender")

或者，如果您想保留无引号语法，还有一个稍微复杂的解决方案：

heatmap=function(sampledata,y)
{
        arguments <- as.list(match.call())
        axis_label <- deparse(substitute(y))
        y = eval(arguments$y, sampledata)

        sampledata$Time <- factor(sampledata$Time)
        sampledata$Grade <- factor(sampledata$Grade)
        sampledata$y <- factor(y)
        color_palette <- colorRampPalette(c("#31a354","#2c7fb8", "#fcbfb8","#f03b20"))(length((levels(factor(sampledata$Grade)))))
        ggplot(data = sampledata) + geom_tile( aes(x = Time, y = y, fill = Grade))+scale_x_discrete(breaks = c("10","20","30","40","50"))+scale_fill_manual(values =color_palette,labels=c("0-1","1-2","2-3","3-4","4-5","5-6",">6"))+  theme_bw()+scale_y_discrete(labels=c("Female","Male")) + ylab(axis_label)
}

# Below an example of how you call the newly defined function
heatmap(sampledata, Gender)