我现在有下面的数据:

V1是考试分数，V3是频数，V4是相应V3的概率

现在想做一幅density plot, 纵轴是概率，横轴是考分，自己试了好几种方法都不满意.. 想请问各位有什么注意吗?

V1 V3 V4
800 0 0
801 0 0
801 0 0
801 0 0
801 0 0
801 0 0
801 0 0
801 0 0
801 0 0
801 0 0
805 0 0
809 0 0
813 0 0
816 1 0.0102040816326531
818 0 0
821 1 0.0102040816326531
823 0 0
824 1 0.0102040816326531
826 1 0.0102040816326531
827 0 0
829 1 0.0102040816326531
830 1 0.0102040816326531
831 1 0.0102040816326531
833 1 0.0102040816326531
834 1 0.0102040816326531
835 1 0.0102040816326531
836 1 0.0102040816326531
837 1 0.0102040816326531
838 1 0.0102040816326531
839 2 0.0204081632653061
840 1 0.0102040816326531
841 2 0.0204081632653061
842 1 0.0102040816326531
843 2 0.0204081632653061
844 2 0.0204081632653061
845 3 0.0306122448979592
846 2 0.0204081632653061
847 3 0.0306122448979592
848 2 0.0204081632653061
849 4 0.0408163265306122
850 3 0.0306122448979592
851 3 0.0306122448979592
852 4 0.0408163265306122
853 4 0.0408163265306122
855 5 0.0510204081632653
856 4 0.0408163265306122
857 5 0.0510204081632653
859 4 0.0408163265306122
860 5 0.0510204081632653
862 5 0.0510204081632653
864 5 0.0510204081632653
866 4 0.0408163265306122
868 4 0.0408163265306122
871 3 0.0306122448979592
875 2 0.0204081632653061
879 1 0.0102040816326531
885 0 0
895 0 0
899 0 0
900 0 0