ggplot2 - 为指示创建堆积的比例直方图，并按人口分开

Essentially, I have a dataset in which I have 4 columns containing the following information: individuals ("Ind"), the geographic population to which those individuals belong ("Pop"), the proportion of their genome that belongs to cluster1 and the proportion of their genome that belongs to cluster2 (these last two add up to 1). Essentially, I have a dataset in which I have 4