R语言数据缩放-1到1
目录
普通scale
-1到1限定范围scale
普通scale
R语言实战：scale（）函数 - 知乎 (zhihu.com)
scale(x, center = TRUE, scale = TRUE)过程：
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对每个变量（列）计算平均值（mean）和标准差（standard deviation）。
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对于每个数据点，将其对应变量的值减去该变量的平均值，然后除以该变量的标准差。
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返回标准化后的数据。
rm(list = ls())##模拟数据
df <- runif(20, -10, 10)
df
[1] 9.7741389 -8.8399498 4.7916575 8.0708620 -9.7996628
[6] 5.6400338 8.5961261 -1.7225669 -6.0895427 5.5806776
[11] 9.8484762 8.5260614 -0.5001188 0.8955994 -8.2918119
[16] -4.9564189 6.0818277 7.4064723 -8.1662199 8.3524912结果：数据超过-1和1
dfscale <- scale(df)
dfscale[1:20]
[1] 1.1244724 -1.4872599 0.4253833 0.8854866 -1.6219167 0.5444185
[7] 0.9591861 -0.4886239 -1.1013518 0.5360902 1.1349026 0.9493554
[13] -0.3171029 -0.1212705 -1.4103510 -0.9423638 0.6064063 0.7922664
[19] -1.3927292 0.9250018-1到1限定范围scale
dplyr - how to rescale/normalize data between -1 and 1 in R using groups - Stack Overflow
使用rescale(df,to = c(-1, 1))函数，并可以限制范围
#数据缩放-1,1之间
library(dplyr)
library(scales)
df1 <- rescale(df,to = c(-1, 1))
df1
[1] 0.99243314 -0.90231003 0.48526233 0.81905521 -1.00000000
[6] 0.57161923 0.87252227 -0.17782586 -0.62234387 0.56557732
[11] 1.00000000 0.86539033 -0.05339187 0.08867942 -0.84651463
[16] -0.50700227 0.61658979 0.75142644 -0.83373052 0.84772247
Rescale continuous vector to have specified minimum and maximumUsage
rescale(x, to, from, ...)x
continuous vector of values to manipulate.to
output range (numeric vector of length two)from
input range (vector of length two). If not given, is calculated from the range of x