如果数据属性不为空，如何用不同颜色对点进行着色
我在R中有一个散点图（用ggplot2）。这些数据有一个数字列（我们称之为 bin ），它可以包含各种整数值或为null。
I have a scatter plot in R (with ggplot2). The data has a numeric column (let's call it bin) which can contain various integer values or null.
I想用不同于其他值的非空bin值对点进行着色。我不希望每个箱子的颜色都有一种颜色，那会太嘈杂。简单地说，对于那些带有非空bin的人来说是红色的，对于其他人是黑色的。
I would like to colour the points with non-null bin values differently from the others. I do not want to one colour per value of bin, that would be too noisy. Just simply, say, red for those with a non-null bin and black for the others.
qplot有一个颜色属性，但我不知道如何表达像 color = bin！= null这样的条件？ red：black
qplot has a colour attribute, but I don't know how to express a condition like colour = bin != null ? "red" : "black"
您可以先定义颜色：
color <- rep("black", length(bin))
color[is.null(color)] <- "red"
否则，您可以使用ifelse语句：
Otherwise you can use an ifelse statement:
colour=ifelse(is.null(bin), "red", "black")