我有以下数据名望df：
author filename a all also
1 dispt dispt_fed_49.txt 0.28 0.052 0.009
2 dispt dispt_fed_50.txt 0.18 0.063 0.013
3 dispt dispt_fed_51.txt 0.34 0.090 0.008
4 dispt dispt_fed_52.txt 0.27 0.024 0.016
5 dispt dispt_fed_53.txt 0.30 0.054 0.027
我想使用以下方法转换为矩阵：
mat <- as.matrix(df)
但是结果将数字列显示为文本：
author filename a all also
[1,] "dispt" "dispt_fed_49.txt" "0.280" "0.052" "0.009"
[2,] "dispt" "dispt_fed_50.txt" "0.177" "0.063" "0.013"
[3,] "dispt" "dispt_fed_51.txt" "0.339" "0.090" "0.008"
[4,] "dispt" "dispt_fed_52.txt" "0.270" "0.024" "0.016"
[5,] "dispt" "dispt_fed_53.txt" "0.303" "0.054" "0.027"
在
时如何将它们保留为数字？