Transform and standardize numeric variables
transform_data.RdApplies a transformation (log, sqrt, inverse, Box-Cox, Yeo-Johnson) or standardization (z-score, centering, scaling, min-max, robust scaling) to selected numeric columns. Group-wise transformation is supported.
Usage
transform_data(data, cols = NULL, method = "log", group = NULL,
lambda = 1.0, verbose = FALSE)Arguments
- data
A data frame or matrix containing numeric variables.
- cols
The column indices or names of selected variables. If NULL, all columns are used.
- method
Transformation method. One of
"log","log1p","sqrt","inverse","boxcox","yeojohnson","zscore","center","scale","minmax","robust".- group
Optional grouping column for group-wise transformation.
- lambda
Parameter for Box-Cox and Yeo-Johnson transformations (default 1.0).
- verbose
Logical; if
TRUE, prints progress message.
Details
For "boxcox", values must be positive. For "yeojohnson", both positive and negative values are allowed. Standardization methods ignore NA values.
Examples
# Log transformation
transform_data(data[1:100, c(1, 4, 17:19)], cols = 3:5, method = "log")
#> date monthyear 3.98 4.47 5.01
#> 1 2019-12-31 16:00:00 January 2020 NA NA NA
#> 2 2019-12-31 16:10:00 January 2020 NA NA NA
#> 3 2019-12-31 16:20:00 January 2020 NA NA NA
#> 4 2019-12-31 16:30:00 January 2020 3.760553 4.314530 3.212355
#> 5 2019-12-31 16:40:00 January 2020 NA 1.926451 3.800367
#> 6 2019-12-31 16:50:00 January 2020 4.115129 NA NA
#> 7 2019-12-31 17:00:00 January 2020 4.752693 NA NA
#> 8 2019-12-31 17:10:00 January 2020 NA NA NA
#> 9 2019-12-31 17:20:00 January 2020 4.115129 NA NA
#> 10 2019-12-31 17:30:00 January 2020 4.109898 1.885735 3.759645
#> 11 2019-12-31 17:40:00 January 2020 NA NA NA
#> 12 2019-12-31 17:50:00 January 2020 NA NA NA
#> 13 2019-12-31 18:00:00 January 2020 NA 2.635465 4.509376
#> 14 2019-12-31 18:10:00 January 2020 NA NA NA
#> 15 2019-12-31 18:20:00 January 2020 4.115129 NA NA
#> 16 2019-12-31 18:30:00 January 2020 4.874915 5.428889 4.326713
#> 17 2019-12-31 18:40:00 January 2020 NA NA NA
#> 18 2019-12-31 18:50:00 January 2020 NA NA NA
#> 19 2019-12-31 19:00:00 January 2020 NA NA NA
#> 20 2019-12-31 19:10:00 January 2020 4.894274 4.998563 3.896383
#> 21 2019-12-31 19:20:00 January 2020 4.115129 NA NA
#> 22 2019-12-31 19:40:00 January 2020 NA NA NA
#> 23 2019-12-31 19:50:00 January 2020 NA NA NA
#> 24 2019-12-31 20:00:00 January 2020 NA NA NA
#> 25 2019-12-31 20:10:00 January 2020 NA NA NA
#> 26 2019-12-31 20:20:00 January 2020 3.758226 4.312204 3.210025
#> 27 2019-12-31 20:30:00 January 2020 3.760553 4.314530 3.212355
#> 28 2019-12-31 20:40:00 January 2020 NA NA NA
#> 29 2019-12-31 20:50:00 January 2020 NA 1.976855 3.850769
#> 30 2019-12-31 21:00:00 January 2020 NA NA NA
#> 31 2019-12-31 21:10:00 January 2020 4.570076 4.278837 3.176661
#> 32 2019-12-31 21:20:00 January 2020 3.683626 4.325602 4.166447
#> 33 2019-12-31 21:30:00 January 2020 4.571613 4.283591 3.181415
#> 34 2019-12-31 21:40:00 January 2020 NA NA NA
#> 35 2019-12-31 21:50:00 January 2020 NA NA NA
#> 36 2019-12-31 22:00:00 January 2020 NA NA NA
#> 37 2019-12-31 22:10:00 January 2020 NA NA NA
#> 38 2019-12-31 22:20:00 January 2020 3.807074 4.361051 3.258873
#> 39 2019-12-31 22:30:00 January 2020 4.115129 NA NA
#> 40 2019-12-31 22:40:00 January 2020 4.414732 5.014003 4.512935
#> 41 2019-12-31 22:50:00 January 2020 NA NA NA
#> 42 2019-12-31 23:00:00 January 2020 4.115129 NA NA
#> 43 2019-12-31 23:10:00 January 2020 NA NA NA
#> 44 2019-12-31 23:20:00 January 2020 4.056648 NA NA
#> 45 2019-12-31 23:30:00 January 2020 NA NA NA
#> 46 2019-12-31 23:40:00 January 2020 NA NA NA
#> 47 2019-12-31 23:50:00 January 2020 4.115129 NA NA
#> 48 2020-01-01 00:00:00 January 2020 NA NA NA
#> 49 2020-01-01 00:10:00 January 2020 NA NA NA
#> 50 2020-01-01 00:20:00 January 2020 NA NA NA
#> 51 2020-01-01 00:30:00 January 2020 NA NA NA
#> 52 2020-01-01 00:40:00 January 2020 3.583424 4.337322 4.710449
#> 53 2020-01-01 00:50:00 January 2020 NA NA NA
#> 54 2020-01-01 01:00:00 January 2020 NA NA NA
#> 55 2020-01-01 01:10:00 January 2020 4.115129 NA NA
#> 56 2020-01-01 01:20:00 January 2020 4.552491 4.333788 3.231610
#> 57 2020-01-01 01:30:00 January 2020 NA 1.888130 3.762046
#> 58 2020-01-01 01:40:00 January 2020 NA 1.942318 3.816228
#> 59 2020-01-01 01:50:00 January 2020 NA NA NA
#> 60 2020-01-01 02:20:00 January 2020 NA NA NA
#> 61 2020-01-01 02:30:00 January 2020 NA NA NA
#> 62 2020-01-01 02:40:00 January 2020 NA NA NA
#> 63 2020-01-01 02:50:00 January 2020 NA NA NA
#> 64 2020-01-01 03:00:00 January 2020 NA NA NA
#> 65 2020-01-01 03:10:00 January 2020 NA NA NA
#> 66 2020-01-01 03:20:00 January 2020 NA NA NA
#> 67 2020-01-01 03:30:00 January 2020 4.808274 NA NA
#> 68 2020-01-01 03:40:00 January 2020 NA NA NA
#> 69 2020-01-01 03:50:00 January 2020 NA NA NA
#> 70 2020-01-01 04:00:00 January 2020 NA NA NA
#> 71 2020-01-01 04:10:00 January 2020 NA NA NA
#> 72 2020-01-01 04:20:00 January 2020 4.865887 4.999527 3.897352
#> 73 2020-01-01 04:30:00 January 2020 NA NA NA
#> 74 2020-01-01 04:40:00 January 2020 NA NA NA
#> 75 2020-01-01 04:50:00 January 2020 NA NA NA
#> 76 2020-01-01 05:00:00 January 2020 NA NA NA
#> 77 2020-01-01 05:40:00 January 2020 NA NA NA
#> 78 2020-01-01 05:50:00 January 2020 NA NA NA
#> 79 2020-01-01 06:00:00 January 2020 NA NA NA
#> 80 2020-01-01 06:10:00 January 2020 NA NA NA
#> 81 2020-01-01 06:20:00 January 2020 NA 1.942318 3.816228
#> 82 2020-01-01 06:30:00 January 2020 NA NA NA
#> 83 2020-01-01 06:40:00 January 2020 NA 3.053199 4.927109
#> 84 2020-01-01 06:50:00 January 2020 NA 2.635465 4.509376
#> 85 2020-01-01 07:00:00 January 2020 NA NA NA
#> 86 2020-01-01 07:10:00 January 2020 NA NA NA
#> 87 2020-01-01 07:20:00 January 2020 4.808274 NA NA
#> 88 2020-01-01 07:30:00 January 2020 NA 1.978682 3.852596
#> 89 2020-01-01 07:40:00 January 2020 3.760553 4.314530 3.212355
#> 90 2020-01-01 07:50:00 January 2020 NA NA NA
#> 91 2020-01-01 08:00:00 January 2020 NA NA NA
#> 92 2020-01-01 08:10:00 January 2020 NA NA NA
#> 93 2020-01-01 08:20:00 January 2020 NA NA NA
#> 94 2020-01-01 08:30:00 January 2020 NA NA NA
#> 95 2020-01-01 08:40:00 January 2020 NA NA NA
#> 96 2020-01-01 08:50:00 January 2020 NA NA NA
#> 97 2020-01-01 09:00:00 January 2020 NA NA NA
#> 98 2020-01-01 09:10:00 January 2020 NA NA NA
#> 99 2020-01-01 09:20:00 January 2020 NA NA NA
#> 100 2020-01-01 09:30:00 January 2020 NA NA NA
# Z-score standardization by group
transform_data(data[1:100, c(1, 4, 17:19)], cols = 3:5, method = "zscore", group = 2)
#> date monthyear 3.98 4.47 5.01
#> 1 2019-12-31 16:00:00 January 2020 NA NA NA
#> 2 2019-12-31 16:10:00 January 2020 NA NA NA
#> 3 2019-12-31 16:20:00 January 2020 NA NA NA
#> 4 2019-12-31 16:30:00 January 2020 -0.9982888 0.1927828 -0.9064783
#> 5 2019-12-31 16:40:00 January 2020 NA -0.9628325 -0.2694683
#> 6 2019-12-31 16:50:00 January 2020 -0.4298319 NA NA
#> 7 2019-12-31 17:00:00 January 2020 1.2684578 NA NA
#> 8 2019-12-31 17:10:00 January 2020 NA NA NA
#> 9 2019-12-31 17:20:00 January 2020 -0.4298319 NA NA
#> 10 2019-12-31 17:30:00 January 2020 -0.4397663 -0.9674932 -0.3266451
#> 11 2019-12-31 17:40:00 January 2020 NA NA NA
#> 12 2019-12-31 17:50:00 January 2020 NA NA NA
#> 13 2019-12-31 18:00:00 January 2020 NA -0.8422792 1.2092173
#> 14 2019-12-31 18:10:00 January 2020 NA NA NA
#> 15 2019-12-31 18:20:00 January 2020 -0.4298319 NA NA
#> 16 2019-12-31 18:30:00 January 2020 1.7367970 2.7982322 0.7231311
#> 17 2019-12-31 18:40:00 January 2020 NA NA NA
#> 18 2019-12-31 18:50:00 January 2020 NA NA NA
#> 19 2019-12-31 19:00:00 January 2020 NA NA NA
#> 20 2019-12-31 19:10:00 January 2020 1.8163714 1.4421240 -0.1250684
#> 21 2019-12-31 19:20:00 January 2020 -0.4298319 NA NA
#> 22 2019-12-31 19:40:00 January 2020 NA NA NA
#> 23 2019-12-31 19:50:00 January 2020 NA NA NA
#> 24 2019-12-31 20:00:00 January 2020 NA NA NA
#> 25 2019-12-31 20:10:00 January 2020 NA NA NA
#> 26 2019-12-31 20:20:00 January 2020 -1.0013940 0.1898254 -0.9083304
#> 27 2019-12-31 20:30:00 January 2020 -0.9982888 0.1927828 -0.9064783
#> 28 2019-12-31 20:40:00 January 2020 NA NA NA
#> 29 2019-12-31 20:50:00 January 2020 NA -0.9567935 -0.1953987
#> 30 2019-12-31 21:00:00 January 2020 NA NA NA
#> 31 2019-12-31 21:10:00 January 2020 0.6671547 0.1481668 -0.9343842
#> 32 2019-12-31 21:20:00 January 2020 -1.0971911 0.2069486 0.3639593
#> 33 2019-12-31 21:30:00 January 2020 0.6717738 0.1540169 -0.9307249
#> 34 2019-12-31 21:40:00 January 2020 NA NA NA
#> 35 2019-12-31 21:50:00 January 2020 NA NA NA
#> 36 2019-12-31 22:00:00 January 2020 NA NA NA
#> 37 2019-12-31 22:10:00 January 2020 NA NA NA
#> 38 2019-12-31 22:20:00 January 2020 -0.9346820 0.2533751 -0.8685815
#> 39 2019-12-31 22:30:00 January 2020 -0.4298319 NA NA
#> 40 2019-12-31 22:40:00 January 2020 0.2353483 1.4813629 1.2195991
#> 41 2019-12-31 22:50:00 January 2020 NA NA NA
#> 42 2019-12-31 23:00:00 January 2020 -0.4298319 NA NA
#> 43 2019-12-31 23:10:00 January 2020 NA NA NA
#> 44 2019-12-31 23:20:00 January 2020 -0.5379972 NA NA
#> 45 2019-12-31 23:30:00 January 2020 NA NA NA
#> 46 2019-12-31 23:40:00 January 2020 NA NA NA
#> 47 2019-12-31 23:50:00 January 2020 -0.4298319 NA NA
#> 48 2020-01-01 00:00:00 January 2020 NA NA NA
#> 49 2020-01-01 00:10:00 January 2020 NA NA NA
#> 50 2020-01-01 00:20:00 January 2020 NA NA NA
#> 51 2020-01-01 00:30:00 January 2020 NA NA NA
#> 52 2020-01-01 00:40:00 January 2020 -1.2151167 0.2221167 1.8576600
#> 53 2020-01-01 00:50:00 January 2020 NA NA NA
#> 54 2020-01-01 01:00:00 January 2020 NA NA NA
#> 55 2020-01-01 01:10:00 January 2020 -0.4298319 NA NA
#> 56 2020-01-01 01:20:00 January 2020 0.6148408 0.2175241 -0.8910049
#> 57 2020-01-01 01:30:00 January 2020 NA -0.9672244 -0.3233383
#> 58 2020-01-01 01:40:00 January 2020 NA -0.9609642 -0.2465611
#> 59 2020-01-01 01:50:00 January 2020 NA NA NA
#> 60 2020-01-01 02:20:00 January 2020 NA NA NA
#> 61 2020-01-01 02:30:00 January 2020 NA NA NA
#> 62 2020-01-01 02:40:00 January 2020 NA NA NA
#> 63 2020-01-01 02:50:00 January 2020 NA NA NA
#> 64 2020-01-01 03:00:00 January 2020 NA NA NA
#> 65 2020-01-01 03:10:00 January 2020 NA NA NA
#> 66 2020-01-01 03:20:00 January 2020 NA NA NA
#> 67 2020-01-01 03:30:00 January 2020 1.4743567 NA NA
#> 68 2020-01-01 03:40:00 January 2020 NA NA NA
#> 69 2020-01-01 03:50:00 January 2020 NA NA NA
#> 70 2020-01-01 04:00:00 January 2020 NA NA NA
#> 71 2020-01-01 04:10:00 January 2020 NA NA NA
#> 72 2020-01-01 04:20:00 January 2020 1.7002114 1.4445573 -0.1235400
#> 73 2020-01-01 04:30:00 January 2020 NA NA NA
#> 74 2020-01-01 04:40:00 January 2020 NA NA NA
#> 75 2020-01-01 04:50:00 January 2020 NA NA NA
#> 76 2020-01-01 05:00:00 January 2020 NA NA NA
#> 77 2020-01-01 05:40:00 January 2020 NA NA NA
#> 78 2020-01-01 05:50:00 January 2020 NA NA NA
#> 79 2020-01-01 06:00:00 January 2020 NA NA NA
#> 80 2020-01-01 06:10:00 January 2020 NA NA NA
#> 81 2020-01-01 06:20:00 January 2020 NA -0.9609642 -0.2465611
#> 82 2020-01-01 06:30:00 January 2020 NA NA NA
#> 83 2020-01-01 06:40:00 January 2020 NA -0.7191990 2.7189008
#> 84 2020-01-01 06:50:00 January 2020 NA -0.8422792 1.2092173
#> 85 2020-01-01 07:00:00 January 2020 NA NA NA
#> 86 2020-01-01 07:10:00 January 2020 NA NA NA
#> 87 2020-01-01 07:20:00 January 2020 1.4743567 NA NA
#> 88 2020-01-01 07:30:00 January 2020 NA -0.9565689 -0.1926430
#> 89 2020-01-01 07:40:00 January 2020 -0.9982888 0.1927828 -0.9064783
#> 90 2020-01-01 07:50:00 January 2020 NA NA NA
#> 91 2020-01-01 08:00:00 January 2020 NA NA NA
#> 92 2020-01-01 08:10:00 January 2020 NA NA NA
#> 93 2020-01-01 08:20:00 January 2020 NA NA NA
#> 94 2020-01-01 08:30:00 January 2020 NA NA NA
#> 95 2020-01-01 08:40:00 January 2020 NA NA NA
#> 96 2020-01-01 08:50:00 January 2020 NA NA NA
#> 97 2020-01-01 09:00:00 January 2020 NA NA NA
#> 98 2020-01-01 09:10:00 January 2020 NA NA NA
#> 99 2020-01-01 09:20:00 January 2020 NA NA NA
#> 100 2020-01-01 09:30:00 January 2020 NA NA NA