如何在 R 資料框中替換完整列?
若要替換 R 資料框中的完整列,我們可以使用 delta 運算子將原始列設定為新值。例如,如果我們有一個名為 df 的資料框,其中包含一列 x,其中 500 個值來自正態分佈,那麼要將其替換為均值為 25 的正態分佈,可以執行 df$x<−rnorm(500,5)。
示例 1
考慮以下資料框 −
x1<−rpois(20,2) x2<−rpois(20,2) x3<−rpois(20,3) df1<−data.frame(x1,x2,x3) df1
輸出
x1 x2 x3 1 1 3 1 2 0 3 1 3 1 4 3 4 4 3 2 5 0 4 1 6 2 3 6 7 2 2 4 8 4 1 2 9 0 4 5 10 1 1 4 11 3 3 1 12 1 3 3 13 1 1 10 14 2 1 3 15 2 3 3 16 1 1 3 17 2 4 8 18 1 3 2 19 1 3 0 20 1 1 0
將 x3 替換為 lambda 2 的泊松分佈 −
示例
df1$x3<−rpois(20,2) df1
輸出
x1 x2 x3 1 1 3 1 2 0 3 2 3 1 4 0 4 4 3 1 5 0 4 3 6 2 3 2 7 2 2 2 8 4 1 3 9 0 4 2 10 1 1 3 11 3 3 1 12 1 3 2 13 1 1 3 14 2 1 0 15 2 3 0 16 1 1 1 17 2 4 2 18 1 3 3 19 1 3 4 20 1 1 1
示例 2
y1<−rnorm(20,1,0.05) y2<−rnorm(20,1,0.75) y3<−rnorm(20,1,0.05) y4<−rnorm(20,1,0.05) df2<−data.frame(y1,y2,y3,y4) df2
輸出
y1 y2 y3 y4 1 1.0141018 0.71738148 0.9420311 1.0009205 2 1.0258060 1.03202326 1.0183309 1.0953612 3 0.9743657 1.58046651 1.0517233 1.0596325 4 1.0199483 1.08089945 0.9873335 0.9910522 5 1.0740019 2.13191506 1.0805077 1.0352464 6 1.0504327 1.55207108 1.0105741 0.9503119 7 0.9656107 1.51496959 1.0856465 1.0721738 8 1.0314142 −0.62997358 0.9007254 0.9555474 9 0.9688579 2.05252761 0.9920891 0.9693772 10 0.9811555 1.58630688 0.9550110 0.9611265 11 0.9594506 1.49768858 0.9792084 0.9442541 12 0.9891804 0.50237995 0.8821927 1.0816134 13 1.0939416 0.16319086 1.0682660 0.9552987 14 1.0437989 2.06159460 1.0034599 0.9708994 15 0.9660916 1.21363074 0.9780202 0.9961647 16 1.0634504 0.82467522 1.0184935 1.0586482 17 0.9907623 1.06935013 1.0507246 0.9516461 18 1.0336085 2.07268738 0.9972536 0.9815386 19 1.0366192 2.20583375 1.0393763 0.9332535 20 1.0861114 0.02966648 1.0502028 0.9452250
將 y2 替換為均值為 1、標準差為 0.05 的正態分佈 −
示例
df2$y2<−rnorm(20,1,0.05) df2
輸出
y1 y2 y3 y4 1 1.0141018 0.9238429 0.9420311 1.0009205 2 1.0258060 0.9940841 1.0183309 1.0953612 3 0.9743657 0.9705115 1.0517233 1.0596325 4 1.0199483 0.9521452 0.9873335 0.9910522 5 1.0740019 0.9531263 1.0805077 1.0352464 6 1.0504327 1.0587658 1.0105741 0.9503119 7 0.9656107 0.9558315 1.0856465 1.0721738 8 1.0314142 1.0368435 0.9007254 0.9555474 9 0.9688579 0.9117594 0.9920891 0.9693772 10 0.9811555 1.0072615 0.9550110 0.9611265 11 0.9594506 0.9935137 0.9792084 0.9442541 12 0.9891804 1.0018355 0.8821927 1.0816134 13 1.0939416 0.9531882 1.0682660 0.9552987 14 1.0437989 0.8805634 1.0034599 0.9708994 15 0.9660916 1.0378592 0.9780202 0.9961647 16 1.0634504 1.0431174 1.0184935 1.0586482 17 0.9907623 1.0666330 1.0507246 0.9516461 18 1.0336085 0.9449561 0.9972536 0.9815386 19 1.0366192 0.9172270 1.0393763 0.9332535 20 1.0861114 0.9739211 1.0502028 0.9452250
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