This function "widens" data, increasing the number of columns and decreasing
the number of rows. This is a dependency-free base-R equivalent of
tidyr::pivot_wider().
Usage
data_to_wide(
data,
id_cols = NULL,
values_from = "Value",
names_from = "Name",
names_sep = "_",
names_prefix = "",
names_glue = NULL,
values_fill = NULL,
verbose = TRUE,
...
)
reshape_wider(
data,
id_cols = NULL,
values_from = "Value",
names_from = "Name",
names_sep = "_",
names_prefix = "",
names_glue = NULL,
values_fill = NULL,
verbose = TRUE,
...
)Arguments
- data
A data frame to convert to wide format, so that it has more columns and fewer rows post-widening than pre-widening.
- id_cols
The name of the column that identifies the rows in the data by which observations are grouped and the gathered data is spread into new columns. Usually, this is a variable containing an ID for observations that have been repeatedly measured. If
NULL, it will use all remaining columns that are not innames_fromorvalues_fromas ID columns.id_colscan also be a character vector with more than one name of identifier columns. See also 'Details' and 'Examples'.- values_from
The name of the columns in the original data that contains the values used to fill the new columns created in the widened data.
- names_from
The name of the column in the original data whose values will be used for naming the new columns created in the widened data. Each unique value in this column will become the name of one of these new columns. In case
names_prefixis provided, column names will be concatenated with the string given innames_prefix.- names_sep
If
names_fromorvalues_fromcontains multiple variables, this will be used to join their values together into a single string to use as a column name.- names_prefix
String added to the start of every variable name. This is particularly useful if
names_fromis a numeric vector and you want to create syntactic variable names.- names_glue
Instead of
names_sepandnames_prefix, you can supply a glue specification that uses thenames_fromcolumns to create custom column names. Note that the only delimiters supported bynames_glueare curly brackets,{and}.- values_fill
Optionally, a (scalar) value that will be used to replace missing values in the new columns created.
- verbose
Toggle warnings.
- ...
Not used for now.
Value
If a tibble was provided as input, data_to_wide() also returns a
tibble. Otherwise, it returns a data frame.
Details
Reshaping data into wide format usually means that the input data frame is
in long format, where multiple measurements taken on the same subject are
stored in multiple rows. The wide format stores the same information in a
single row, with each measurement stored in a separate column. Thus, the
necessary information for data_to_wide() is:
The name of the column(s) that identify the groups or repeated measurements (
id_cols).The name of the column whose values will become the new column names (
names_from). Since these values may not necessarily reflect appropriate column names, you can usenames_prefixto add a prefix to each newly created column name.The name of the column that contains the values (
values_from) for the new columns that are created bynames_from.
In other words: repeated measurements, as indicated by id_cols, that are
saved into the column values_from will be spread into new columns, which
will be named after the values in names_from. See also 'Examples'.
See also
Add a prefix or suffix to column names:
data_addprefix(),data_addsuffix()Functions to reorder or remove columns:
data_reorder(),data_relocate(),data_remove()Functions to reshape, pivot or rotate data frames:
data_to_long(),data_to_wide(),data_rotate()Functions to recode data:
rescale(),reverse(),categorize(),recode_values(),slide()Functions to standardize, normalize, rank-transform:
center(),standardize(),normalize(),ranktransform(),winsorize()Split and merge data frames:
data_partition(),data_merge()Functions to find or select columns:
data_select(),extract_column_names()Functions to filter rows:
data_match(),data_filter()
Examples
data_long <- read.table(header = TRUE, text = "
subject sex condition measurement
1 M control 7.9
1 M cond1 12.3
1 M cond2 10.7
2 F control 6.3
2 F cond1 10.6
2 F cond2 11.1
3 F control 9.5
3 F cond1 13.1
3 F cond2 13.8
4 M control 11.5
4 M cond1 13.4
4 M cond2 12.9")
# converting long data into wide format
data_to_wide(
data_long,
id_cols = "subject",
names_from = "condition",
values_from = "measurement"
)
#> subject control cond1 cond2
#> 1 1 7.9 12.3 10.7
#> 2 2 6.3 10.6 11.1
#> 3 3 9.5 13.1 13.8
#> 4 4 11.5 13.4 12.9
# converting long data into wide format with custom column names
data_to_wide(
data_long,
id_cols = "subject",
names_from = "condition",
values_from = "measurement",
names_prefix = "Var.",
names_sep = "."
)
#> subject Var.control Var.cond1 Var.cond2
#> 1 1 7.9 12.3 10.7
#> 2 2 6.3 10.6 11.1
#> 3 3 9.5 13.1 13.8
#> 4 4 11.5 13.4 12.9
# converting long data into wide format, combining multiple columns
production <- expand.grid(
product = c("A", "B"),
country = c("AI", "EI"),
year = 2000:2014
)
production <- data_filter(production, (product == "A" & country == "AI") | product == "B")
production$production <- rnorm(nrow(production))
data_to_wide(
production,
names_from = c("product", "country"),
values_from = "production",
names_glue = "prod_{product}_{country}"
)
#> year prod_A_AI prod_B_AI prod_B_EI
#> 1 2000 -0.7843822 -0.73350322 -0.21586539
#> 2 2001 -0.3349128 -1.08569914 -0.08542326
#> 3 2002 1.0706105 -0.14539355 -1.16554485
#> 4 2003 -0.8185157 0.68493608 -0.32005642
#> 5 2004 -1.3115224 -0.59960833 -0.12941069
#> 6 2005 0.8867361 -0.15139596 0.32979120
#> 7 2006 -3.2273228 -0.77179177 0.28654857
#> 8 2007 -1.2205120 0.43455038 0.80017687
#> 9 2008 -0.1639310 1.24291877 -0.93438506
#> 10 2009 0.3937087 0.40363146 -0.88643672
#> 11 2010 -1.3189376 0.02884391 -0.43212979
#> 12 2011 1.6898725 1.22839278 0.27602348
#> 13 2012 -1.0489755 -0.52086934 1.62320252
#> 14 2013 -1.0700682 1.68588724 -0.24168977
#> 15 2014 -0.4682005 -0.77297823 2.14991934
# using the "sleepstudy" dataset
data(sleepstudy, package = "lme4")
# the sleepstudy data contains repeated measurements of average reaction
# times for each subjects over multiple days, in a sleep deprivation study.
# It is in long-format, i.e. each row corresponds to a single measurement.
# The variable "Days" contains the timepoint of the measurement, and
# "Reaction" contains the measurement itself. Converting this data to wide
# format will create a new column for each day, with the reaction time as the
# value.
head(sleepstudy)
#> Reaction Days Subject
#> 1 249.5600 0 308
#> 2 258.7047 1 308
#> 3 250.8006 2 308
#> 4 321.4398 3 308
#> 5 356.8519 4 308
#> 6 414.6901 5 308
data_to_wide(
sleepstudy,
id_cols = "Subject",
names_from = "Days",
values_from = "Reaction"
)
#> Subject 0 1 2 3 4 5 6
#> 1 308 249.5600 258.7047 250.8006 321.4398 356.8519 414.6901 382.2038
#> 2 309 222.7339 205.2658 202.9778 204.7070 207.7161 215.9618 213.6303
#> 3 310 199.0539 194.3322 234.3200 232.8416 229.3074 220.4579 235.4208
#> 4 330 321.5426 300.4002 283.8565 285.1330 285.7973 297.5855 280.2396
#> 5 331 287.6079 285.0000 301.8206 320.1153 316.2773 293.3187 290.0750
#> 6 332 234.8606 242.8118 272.9613 309.7688 317.4629 309.9976 454.1619
#> 7 333 283.8424 289.5550 276.7693 299.8097 297.1710 338.1665 332.0265
#> 8 334 265.4731 276.2012 243.3647 254.6723 279.0244 284.1912 305.5248
#> 9 335 241.6083 273.9472 254.4907 270.8021 251.4519 254.6362 245.4523
#> 10 337 312.3666 313.8058 291.6112 346.1222 365.7324 391.8385 404.2601
#> 11 349 236.1032 230.3167 238.9256 254.9220 250.7103 269.7744 281.5648
#> 12 350 256.2968 243.4543 256.2046 255.5271 268.9165 329.7247 379.4445
#> 13 351 250.5265 300.0576 269.8939 280.5891 271.8274 304.6336 287.7466
#> 14 352 221.6771 298.1939 326.8785 346.8555 348.7402 352.8287 354.4266
#> 15 369 271.9235 268.4369 257.2424 277.6566 314.8222 317.2135 298.1353
#> 16 370 225.2640 234.5235 238.9008 240.4730 267.5373 344.1937 281.1481
#> 17 371 269.8804 272.4428 277.8989 281.7895 279.1705 284.5120 259.2658
#> 18 372 269.4117 273.4740 297.5968 310.6316 287.1726 329.6076 334.4818
#> 7 8 9
#> 1 290.1486 430.5853 466.3535
#> 2 217.7272 224.2957 237.3142
#> 3 255.7511 261.0125 247.5153
#> 4 318.2613 305.3495 354.0487
#> 5 334.8177 293.7469 371.5811
#> 6 346.8311 330.3003 253.8644
#> 7 348.8399 333.3600 362.0428
#> 8 331.5229 335.7469 377.2990
#> 9 235.3110 235.7541 237.2466
#> 10 416.6923 455.8643 458.9167
#> 11 308.1020 336.2806 351.6451
#> 12 362.9184 394.4872 389.0527
#> 13 266.5955 321.5418 347.5655
#> 14 360.4326 375.6406 388.5417
#> 15 348.1229 340.2800 366.5131
#> 16 347.5855 365.1630 372.2288
#> 17 304.6306 350.7807 369.4692
#> 18 343.2199 369.1417 364.1236
# clearer column names
data_to_wide(
sleepstudy,
id_cols = "Subject",
names_from = "Days",
values_from = "Reaction",
names_prefix = "Reaction_Day_"
)
#> Subject Reaction_Day_0 Reaction_Day_1 Reaction_Day_2 Reaction_Day_3
#> 1 308 249.5600 258.7047 250.8006 321.4398
#> 2 309 222.7339 205.2658 202.9778 204.7070
#> 3 310 199.0539 194.3322 234.3200 232.8416
#> 4 330 321.5426 300.4002 283.8565 285.1330
#> 5 331 287.6079 285.0000 301.8206 320.1153
#> 6 332 234.8606 242.8118 272.9613 309.7688
#> 7 333 283.8424 289.5550 276.7693 299.8097
#> 8 334 265.4731 276.2012 243.3647 254.6723
#> 9 335 241.6083 273.9472 254.4907 270.8021
#> 10 337 312.3666 313.8058 291.6112 346.1222
#> 11 349 236.1032 230.3167 238.9256 254.9220
#> 12 350 256.2968 243.4543 256.2046 255.5271
#> 13 351 250.5265 300.0576 269.8939 280.5891
#> 14 352 221.6771 298.1939 326.8785 346.8555
#> 15 369 271.9235 268.4369 257.2424 277.6566
#> 16 370 225.2640 234.5235 238.9008 240.4730
#> 17 371 269.8804 272.4428 277.8989 281.7895
#> 18 372 269.4117 273.4740 297.5968 310.6316
#> Reaction_Day_4 Reaction_Day_5 Reaction_Day_6 Reaction_Day_7 Reaction_Day_8
#> 1 356.8519 414.6901 382.2038 290.1486 430.5853
#> 2 207.7161 215.9618 213.6303 217.7272 224.2957
#> 3 229.3074 220.4579 235.4208 255.7511 261.0125
#> 4 285.7973 297.5855 280.2396 318.2613 305.3495
#> 5 316.2773 293.3187 290.0750 334.8177 293.7469
#> 6 317.4629 309.9976 454.1619 346.8311 330.3003
#> 7 297.1710 338.1665 332.0265 348.8399 333.3600
#> 8 279.0244 284.1912 305.5248 331.5229 335.7469
#> 9 251.4519 254.6362 245.4523 235.3110 235.7541
#> 10 365.7324 391.8385 404.2601 416.6923 455.8643
#> 11 250.7103 269.7744 281.5648 308.1020 336.2806
#> 12 268.9165 329.7247 379.4445 362.9184 394.4872
#> 13 271.8274 304.6336 287.7466 266.5955 321.5418
#> 14 348.7402 352.8287 354.4266 360.4326 375.6406
#> 15 314.8222 317.2135 298.1353 348.1229 340.2800
#> 16 267.5373 344.1937 281.1481 347.5855 365.1630
#> 17 279.1705 284.5120 259.2658 304.6306 350.7807
#> 18 287.1726 329.6076 334.4818 343.2199 369.1417
#> Reaction_Day_9
#> 1 466.3535
#> 2 237.3142
#> 3 247.5153
#> 4 354.0487
#> 5 371.5811
#> 6 253.8644
#> 7 362.0428
#> 8 377.2990
#> 9 237.2466
#> 10 458.9167
#> 11 351.6451
#> 12 389.0527
#> 13 347.5655
#> 14 388.5417
#> 15 366.5131
#> 16 372.2288
#> 17 369.4692
#> 18 364.1236
# For unequal group sizes, missing information is filled with NA
d <- subset(sleepstudy, Days %in% c(0, 1, 2, 3, 4))[c(1:9, 11:13, 16:17, 21), ]
# long format, different number of "Subjects"
d
#> Reaction Days Subject
#> 1 249.5600 0 308
#> 2 258.7047 1 308
#> 3 250.8006 2 308
#> 4 321.4398 3 308
#> 5 356.8519 4 308
#> 11 222.7339 0 309
#> 12 205.2658 1 309
#> 13 202.9778 2 309
#> 14 204.7070 3 309
#> 21 199.0539 0 310
#> 22 194.3322 1 310
#> 23 234.3200 2 310
#> 31 321.5426 0 330
#> 32 300.4002 1 330
#> 41 287.6079 0 331
data_to_wide(
d,
id_cols = "Subject",
names_from = "Days",
values_from = "Reaction",
names_prefix = "Reaction_Day_"
)
#> Subject Reaction_Day_0 Reaction_Day_1 Reaction_Day_2 Reaction_Day_3
#> 1 308 249.5600 258.7047 250.8006 321.4398
#> 2 309 222.7339 205.2658 202.9778 204.7070
#> 3 310 199.0539 194.3322 234.3200 NA
#> 4 330 321.5426 300.4002 NA NA
#> 5 331 287.6079 NA NA NA
#> Reaction_Day_4
#> 1 356.8519
#> 2 NA
#> 3 NA
#> 4 NA
#> 5 NA
# filling missing values with 0
data_to_wide(
d,
id_cols = "Subject",
names_from = "Days",
values_from = "Reaction",
names_prefix = "Reaction_Day_",
values_fill = 0
)
#> Subject Reaction_Day_0 Reaction_Day_1 Reaction_Day_2 Reaction_Day_3
#> 1 308 249.5600 258.7047 250.8006 321.4398
#> 2 309 222.7339 205.2658 202.9778 204.7070
#> 3 310 199.0539 194.3322 234.3200 0.0000
#> 4 330 321.5426 300.4002 0.0000 0.0000
#> 5 331 287.6079 0.0000 0.0000 0.0000
#> Reaction_Day_4
#> 1 356.8519
#> 2 0.0000
#> 3 0.0000
#> 4 0.0000
#> 5 0.0000