by-sample.RdA data frame is split according to some variables in a formula, and a sample of a certain fraction of each is drawn.
sample_by(data, formula, frac = 0.1, replace = FALSE, systematic = FALSE)
sampleBy(
formula,
frac = 0.1,
replace = FALSE,
data = parent.frame(),
systematic = FALSE
)A data frame.
A formula defining the grouping of the data frame.
The part of data to be sampled.
Is the sampling with replacement.
Should sampling be systematic.
A dataframe.
If systematic=FALSE (default) then frac gives the fraction of data sampled. If systematic=TRUE and frac=.2 then every 1/.2 i.e. every 5th observation is taken out.
data(dietox)
sampleBy(formula = ~ Evit + Cu, frac=.1, data = dietox)
#> Pig Evit Cu Litter Start Weight Feed Time
#> Evit000|Cu000.1 4601 Evit000 Cu000 1 26.50000 26.50000 NA 1
#> Evit000|Cu000.97 4757 Evit000 Cu000 3 26.89999 26.89999 NA 1
#> Evit000|Cu000.106 4757 Evit000 Cu000 3 26.89999 81.00000 129.000000 10
#> Evit000|Cu000.193 4856 Evit000 Cu000 6 32.00000 32.00000 NA 1
#> Evit000|Cu000.202 4856 Evit000 Cu000 6 32.00000 92.50000 131.000000 10
#> Evit000|Cu000.255 5497 Evit000 Cu000 8 21.20000 29.39999 16.500000 3
#> Evit000|Cu000.398 5852 Evit000 Cu000 12 23.79999 50.39999 44.900002 5
#> Evit000|Cu000.403 5852 Evit000 Cu000 12 23.79999 91.19995 132.000000 10
#> Evit000|Cu035.14 4602 Evit000 Cu035 1 28.29999 30.09999 3.300003 2
#> Evit000|Cu035.20 4602 Evit000 Cu035 1 28.29999 73.00000 90.800003 8
#> Evit000|Cu035.268 5500 Evit000 Cu035 8 17.00000 29.39999 32.800003 4
#> Evit000|Cu035.273 5500 Evit000 Cu035 8 17.00000 62.50000 103.800003 9
#> Evit000|Cu035.275 5500 Evit000 Cu035 8 17.00000 78.29999 147.300001 11
#> Evit000|Cu035.417 5862 Evit000 Cu035 11 22.00000 93.19995 147.700005 12
#> Evit000|Cu035.708 8142 Evit000 Cu035 23 25.20000 35.69998 21.000000 3
#> Evit000|Cu035.716 8142 Evit000 Cu035 23 25.20000 89.39996 138.500000 11
#> Evit000|Cu035.816 8273 Evit000 Cu035 22 25.00000 37.09998 20.000000 3
#> Evit000|Cu035.821 8273 Evit000 Cu035 22 25.00000 78.19995 102.000000 8
#> Evit200|Cu175.26 4603 Evit200 Cu175 1 27.59999 30.59999 6.700005 2
#> Evit200|Cu175.27 4603 Evit200 Cu175 1 27.59999 38.69998 17.600000 3
#> Evit200|Cu175.30 4603 Evit200 Cu175 1 27.59999 61.50000 64.600002 6
#> Evit200|Cu175.235 5389 Evit200 Cu175 7 24.29999 58.09998 69.000002 7
#> Evit200|Cu175.238 5389 Evit200 Cu175 7 24.29999 78.39996 114.200003 10
#> Evit200|Cu175.383 5851 Evit200 Cu175 12 22.29999 24.70000 5.900002 2
#> Evit200|Cu175.385 5851 Evit200 Cu175 12 22.29999 36.89999 25.200001 4
#> Evit200|Cu175.673 8053 Evit200 Cu175 20 21.89999 41.29999 36.700001 4
#> Evit200|Cu175.674 8053 Evit200 Cu175 20 21.89999 48.69998 51.800003 5
#> Evit200|Cu175.677 8053 Evit200 Cu175 20 21.89999 71.29999 115.800003 8
#> Evit100|Cu035.48 4605 Evit100 Cu035 1 31.50000 109.19995 176.400002 12
#> Evit100|Cu035.218 4858 Evit100 Cu035 6 28.00000 31.20000 8.000000 2
#> Evit100|Cu035.220 4858 Evit100 Cu035 6 28.00000 44.69998 31.800003 4
#> Evit100|Cu035.578 6432 Evit100 Cu035 5 25.09999 44.19998 31.000000 5
#> Evit100|Cu035.579 6432 Evit100 Cu035 5 25.09999 52.79999 56.300003 6
#> Evit100|Cu035.663 8051 Evit100 Cu035 20 30.59999 62.39999 65.000000 6
#> Evit100|Cu035.669 8051 Evit100 Cu035 20 30.59999 112.50000 196.900002 12
#> Evit100|Cu035.722 8144 Evit100 Cu035 23 23.50000 29.79999 29.500000 5
#> Evit100|Cu035.723 8144 Evit100 Cu035 23 23.50000 32.79999 34.000000 6
#> Evit100|Cu035.728 8144 Evit100 Cu035 23 23.50000 72.09998 111.200005 11
#> Evit100|Cu175.53 4641 Evit100 Cu175 2 27.09999 56.50000 53.300003 5
#> Evit100|Cu175.157 4815 Evit100 Cu175 4 24.89999 24.89999 NA 1
#> Evit100|Cu175.158 4815 Evit100 Cu175 4 24.89999 29.70000 9.500000 2
#> Evit100|Cu175.161 4815 Evit100 Cu175 4 24.89999 48.29999 45.500000 5
#> Evit100|Cu175.284 5501 Evit100 Cu175 8 30.00000 77.39996 92.800003 8
#> Evit100|Cu175.285 5501 Evit100 Cu175 8 30.00000 86.00000 110.000000 9
#> Evit100|Cu175.439 5866 Evit100 Cu175 11 22.00000 75.00000 109.900002 10
#> Evit100|Cu175.470 6057 Evit100 Cu175 16 27.00000 53.19998 44.800003 5
#> Evit100|Cu175.471 6057 Evit100 Cu175 16 27.00000 62.39999 60.000000 6
#> Evit100|Cu175.476 6057 Evit100 Cu175 16 27.00000 103.00000 147.800003 11
#> Evit200|Cu035.79 4645 Evit200 Cu035 2 27.70000 69.79999 88.000000 7
#> Evit200|Cu035.83 4645 Evit200 Cu035 2 27.70000 96.79999 157.200001 11
#> Evit200|Cu035.119 4759 Evit200 Cu035 3 22.59999 89.39996 152.100002 11
#> Evit200|Cu035.249 5392 Evit200 Cu035 7 24.59999 63.00000 89.499996 9
#> Evit200|Cu035.250 5392 Evit200 Cu035 7 24.59999 75.69995 104.999996 10
#> Evit200|Cu035.252 5392 Evit200 Cu035 7 24.59999 88.69995 142.799997 12
#> Evit200|Cu035.444 6055 Evit200 Cu035 16 26.20000 37.39999 18.200001 3
#> Evit200|Cu035.448 6055 Evit200 Cu035 16 26.20000 64.19995 87.200001 7
#> Evit200|Cu035.561 6288 Evit200 Cu035 18 24.09999 101.59998 161.800003 12
#> Evit200|Cu035.598 6909 Evit200 Cu035 13 24.70000 24.70000 NA 1
#> Evit200|Cu035.697 8141 Evit200 Cu035 23 24.20000 35.59998 24.600002 4
#> Evit200|Cu000.88 4756 Evit200 Cu000 3 17.00000 30.00000 28.900002 4
#> Evit200|Cu000.299 5502 Evit200 Cu000 8 29.59999 96.39996 145.200001 11
#> Evit200|Cu000.323 5528 Evit200 Cu000 9 24.00000 24.00000 NA 1
#> Evit200|Cu000.333 5528 Evit200 Cu000 9 24.00000 92.50000 146.100000 11
#> Evit200|Cu000.348 5581 Evit200 Cu000 10 27.00000 37.79999 19.500000 3
#> Evit200|Cu000.353 5581 Evit200 Cu000 10 27.00000 70.50000 97.000000 8
#> Evit200|Cu000.355 5581 Evit200 Cu000 10 27.00000 92.00000 138.800003 10
#> Evit200|Cu000.375 5850 Evit200 Cu000 12 22.79999 48.19998 48.000000 6
#> Evit200|Cu000.381 5850 Evit200 Cu000 12 22.79999 94.00000 146.800001 12
#> Evit200|Cu000.632 6912 Evit200 Cu000 13 24.50000 98.89996 143.000000 11
#> Evit000|Cu175.169 4817 Evit000 Cu175 4 24.59999 24.59999 NA 1
#> Evit000|Cu175.173 4817 Evit000 Cu175 4 24.59999 49.69998 47.000004 5
#> Evit000|Cu175.175 4817 Evit000 Cu175 4 24.59999 66.89996 83.300003 7
#> Evit000|Cu175.214 4857 Evit000 Cu175 6 26.00000 86.00000 135.300007 10
#> Evit000|Cu175.650 8050 Evit000 Cu175 20 26.79999 56.19998 54.400002 5
#> Evit000|Cu175.657 8050 Evit000 Cu175 20 26.79999 112.00000 224.000000 12
#> Evit000|Cu175.684 8139 Evit000 Cu175 23 24.00000 33.00000 20.000000 3
#> Evit000|Cu175.791 8270 Evit000 Cu175 22 23.70000 28.79999 7.600000 2
#> Evit000|Cu175.793 8270 Evit000 Cu175 22 23.70000 43.00000 33.200001 4
#> Evit000|Cu175.799 8270 Evit000 Cu175 22 23.70000 90.69995 133.200001 10
#> Evit100|Cu000.183 4854 Evit100 Cu000 6 29.00000 38.29999 19.800003 3
#> Evit100|Cu000.187 4854 Evit100 Cu000 6 29.00000 62.59998 70.000000 7
#> Evit100|Cu000.191 4854 Evit100 Cu000 6 29.00000 85.50000 138.500000 11
#> Evit100|Cu000.192 4854 Evit100 Cu000 6 29.00000 93.09998 158.000000 12
#> Evit100|Cu000.517 6211 Evit100 Cu000 17 24.50000 46.39999 30.100006 4
#> Evit100|Cu000.527 6284 Evit100 Cu000 18 23.09999 26.00000 5.900002 2
#> Evit100|Cu000.591 6433 Evit100 Cu000 5 32.19998 60.09998 58.600000 6
#> Evit100|Cu000.596 6433 Evit100 Cu000 5 32.19998 111.09998 163.000000 11
#> Evit100|Cu000.803 8271 Evit100 Cu000 22 24.00000 28.89999 8.500000 2
#> Evit100|Cu000.813 8271 Evit100 Cu000 22 24.00000 99.79999 158.100000 12