Title: | Create Relationally-Specified Multi-Table Datasets |
---|---|
Description: | This package provides a general framework and utility functions for simulating or synthesizing database-like multiple-table datasets. This is done by defining and then applying data recipes, which support the simulation or derivation of multiple variables jointly and/or conditional on the value of other already existing or recipe-specified variables. It also supports the simulation or augmentation of data which encodes a 1-to-many relationship with a foreign-key in an existing table. |
Authors: | Gabriel Becker [aut, cre] |
Maintainer: | Gabriel Becker <[email protected]> |
License: | Artistic-2.0 |
Version: | 0.0.4.9000 |
Built: | 2024-11-17 06:11:25 UTC |
Source: | https://github.com/Roche/respectables |
Generate full db from a Cookbook of Recipes
gen_data_db( cbook, db = list(), ns = setNames(rep(500, NROW(cbook)), cbook$table) )
gen_data_db( cbook, db = list(), ns = setNames(rep(500, NROW(cbook)), cbook$table) )
cbook |
tribble. Columns: table, scaff_ref, data_rec, na_rec |
db |
list. Named list of already existing tables |
ns |
named numeric. Ns for use when generating independent tables. |
A named list of tables of generated data.
Generate synthetic data relationally-linked to existing data
gen_reljoin_table( joinrec, tblrec, miss_recipe = NULL, db, keep = NA_character_ )
gen_reljoin_table( joinrec, tblrec, miss_recipe = NULL, db, keep = NA_character_ )
joinrec |
tibble. Recipe for synthesizing core/seed data based of a foreign key present in an existing table
within |
tblrec |
tibble. Recipe for generating the remainder of the new table, via |
miss_recipe |
tibble or NULL. A missingness recipe, if desired, to be applied after data generation via
|
db |
list. A named list of existing tibbles/data.frames. The names will be used to resolve foreign table
references in |
keep |
TODO |
In relational database terms, this function synthesizes
new data in a table which has a foreign key in a table existing
already within db
. Typically it will not generate data
in the same dimension as the foreign table (as in that case the
new data could simply be columns added to the existing
table). Instead, it generally has the possibility of multiple
rows for a particular foreign-key value, the possibility a
foreign key value is not present at all, or both. A concrete
example of this is Adverse Events being mapped to patients
(USUBJID in CDISC terms). Some patients will have multiple
adverse events, while many will have none at all.
This is done via 3 steps:
1. Applying the relational join recipe. The "relational join recipe" step should be considered primarily as the mechanism for defining the dimensions of the new data table.
2. The main data synthesis step, which is done by applying the
tblrec
recipe on the scaffolding provided by the newly
dimensioned table generated in step 1.
3. Injecting missingness (optional) using missrec
.
The newly synthesized data table.
Generate variables in a table
gen_table_data( N = if (is.null(df)) 400 else NROW(df), recipe, df = NULL, df_keepcols = if (is.null(df)) character() else names(df), miss_recipe = NULL )
gen_table_data( N = if (is.null(df)) 400 else NROW(df), recipe, df = NULL, df_keepcols = if (is.null(df)) character() else names(df), miss_recipe = NULL )
N |
numeric(1). Number of rows to generate. Defaults to 400, or the number of rows in |
recipe |
tibble. A recipe for generating variables into the dataset. see |
df |
data.frame/tibble. Existing partial data which new variables should be added to, or |
df_keepcols |
logical. which columns from |
miss_recipe |
tibble. A recipe for generating missingness positions, or |
The recipe
parameter should be a tibble made up of one or more rows which define variable recipes via the following
columns:
(list column as needed) names of variables generated by that row. No empty/length 0 entries allowed
(list column). Names of variables which must have already been populated for the the variables in this row to be synthesized
(list column) A character value which can be used to look up a function, or the function object itself, which accepts n, .df, and ... and returns either an atomic vector of length n
, or a data.frame/tibble with n rows
(list column) a list of arguments which should be passed to func
in addition to n
and .df
The algorithm for synthesizing the table from the recipe is as follows:
Columns of synthesized data are generated according to recipe rows which have no dependencies in the order they appear in the recipe tibble and appended to the dataset with names for the variables generated
Recipe rows containing dependencies are checked in the order they appear in the recipe table for whether their dependencies are met, and if so data is synthesized for the corresponding variables and added to the dataset. This step is repeated until all recipe rows have been resolved, or until a full pass through the unresolved recipe rows does not lead to any new data synthesis.
After all data synthesis is complete, columns are then reordered based on any columns of df
first, followed by newly synthesized variables in the order the appear in the recipe table's variables
column.
library(tibble) dat <- cbind(model = row.names(mtcars), as_tibble(mtcars)) recipe <- tribble(~variables, ~dependencies, ~func, ~func_args, "id", no_deps, "seq_n", NULL, "specialid", "id", function(n, .df) paste0("special-", .df$id), NULL) gen_table_data(10, recipe)
library(tibble) dat <- cbind(model = row.names(mtcars), as_tibble(mtcars)) recipe <- tribble(~variables, ~dependencies, ~func, ~func_args, "id", no_deps, "seq_n", NULL, "specialid", "id", function(n, .df) paste0("special-", .df$id), NULL) gen_table_data(10, recipe)
Initialize new columns of the correct length
init_new_cols( n, colnames = names(colclasses), colclasses = setNames(rep(NA, length(colnames)), colnames) )
init_new_cols( n, colnames = names(colclasses), colclasses = setNames(rep(NA, length(colnames)), colnames) )
n |
numeric(1). The length (number of rows) to use when initializing. |
colnames |
character. Vector of column names to use. Can be omitted if |
colclasses |
named character. Optional. Names must be identical to |
A data.frame with the new columns and n
rows.
init_new_cols(5, c("col1", "col2")) init_new_cols(5, colclasses = c(col1 = NA, col2 = "integer"))
init_new_cols(5, c("col1", "col2")) init_new_cols(5, colclasses = c(col1 = NA, col2 = "integer"))
Apply random or systematic missingness to existing data according to recipe
inject_nas(tbl, recipe)
inject_nas(tbl, recipe)
tbl |
data.frame/tibble. The already generated data to inject missingness into |
recipe |
tibble. A recipe for generating missingness positions |
Unlike in data-generation recipes, the func
column in a missingness recipe must return a logical
vector of length n or an n x k logical matrix, where n is the number of rows in .df
and k
is the
number of variables listed in this row of the recipe. A vector is only allowed when only one variable is listed in
the recipe row (ie k=1
). TRUE
in the return value indicates that position in the column being
processed should be set to missing (NA
), while FALSE
indicates the value already there should remain
unchanged.
tbl
, with missingness injected into it as laid out by recipe
library(tibble) missrec <- tibble(variables = "wt", func = list(function(.df) rep(c(TRUE, FALSE), times = c(3, NROW(.df) - 3))), func_args = list(NULL)) newdat <- inject_nas(mtcars, missrec) head(newdat)
library(tibble) missrec <- tibble(variables = "wt", func = list(function(.df) rep(c(TRUE, FALSE), times = c(3, NROW(.df) - 3))), func_args = list(NULL)) newdat <- inject_nas(mtcars, missrec) head(newdat)
This function is an internal utility exported for its usefulness when debugging recipes. Normal workflows will not involve calling it directly.
lookup_fun(str)
lookup_fun(str)
str |
ANY. A function (immediately returned) or a character(1) value of the form |
A function
lookup_fun(rnorm) lookup_fun("rnorm") lookup_fun("stats::rnorm") lookup_fun("stats:::rnorm")
lookup_fun(rnorm) lookup_fun("rnorm") lookup_fun("stats::rnorm") lookup_fun("stats:::rnorm")
This constructor creates a function which will set all nvars
columns
to NA together for rows selected for missing data.
miss_as_block(p, nvars)
miss_as_block(p, nvars)
p |
numeric(1). Proportion of observations to change to missing |
nvars |
numeric(1). Number of columns this behavior should be applied to. |
a function suitable for use in missingness recipe, which when given .df
, the data
will return an N x nvars logical matrix.
Function constructor for injecting independent missing-at-random NAs to columns
miss_at_random(p, nvars)
miss_at_random(p, nvars)
p |
numeric(1). Proportion of observations to change to missing |
nvars |
numeric(1). Number of columns this behavior should be applied to. |
a function suitable for use in missingness recipe, which when given .df
, the data
will return an N x nvars logical matrix.
Sentinel Values for Recipes
no_key no_deps no_rec no_args
no_key no_deps no_rec no_args
An object of class character
of length 0.
An object of class character
of length 0.
An object of class list
of length 0.
An object of class list
of length 0.
Generates random datetimes that are, elementwise, between start
and end
pct_orig secs_per_year secs_per_day rand_posixct( start, end, max_duration_secs = NULL, multiplier = if (is(start, "Date")) secs_per_day else 1, n = max(length(start), length(end)) )
pct_orig secs_per_year secs_per_day rand_posixct( start, end, max_duration_secs = NULL, multiplier = if (is(start, "Date")) secs_per_day else 1, n = max(length(start), length(end)) )
start |
POSIXct or Date. Earliest possible datetime for thte sample |
end |
POSIXct or Date. latest possible datetime for thte sample |
max_duration_secs |
numeric. Number of seconds to use to generate alernate end if |
multiplier |
numeric. Used internally. |
n |
numeric. Length of sample. Default to max of |
An object of class character
of length 1.
An object of class numeric
of length 1.
An object of class numeric
of length 1.
A POSIXct
vector of datetimes.
rand_posixct("2020-01-01", "2021-01-01", n = 2) rand_posixct(c("1995-04-01", "2000-01-01"), c("2000-04-01", "2000-01-30"))
rand_posixct("2020-01-01", "2021-01-01", n = 2) rand_posixct(c("1995-04-01", "2000-01-01"), c("2000-04-01", "2000-01-30"))
These function constructors create functions suitable for use in relational-join recipes that expand or contract the row-dimension of the incoming data.
rep_per_key(keyvar, tblnm, count, prop_present = 1) rand_per_key(keyvar, tblnm, mincount = 1, maxcount = 20, prop_present = 0.5)
rep_per_key(keyvar, tblnm, count, prop_present = 1) rand_per_key(keyvar, tblnm, mincount = 1, maxcount = 20, prop_present = 0.5)
keyvar |
character(1). The name of the column to treat as a foreign key. |
tblnm |
character(1). The name of the table in the database in which to find the keyvar |
count |
numeric(1). The number of times each foreign-key value should appear in the scaffold data. |
prop_present |
numeric(1). Proportion of the key values in the foreign table to include rows for in the dimension-scaffold. Defaults to 1 (all values present). |
mincount |
numeric(1). Minimum replications for a present key |
maxcount |
numeric(1). Maximum replications for a pressent key |
rep_per_key
creates functions which generate dimension-scaffolds
that contain a constant number of rows per key value (ie row of
the incoming data), e.g., the the map from ADSL requires 3 rows per
patient (foreign key) to synthesize the long-form PARAMCD-based
ADTTE data.
rand_per_key
creates functions which generate dimension-scaffolds
which contain a uniformly distributed random number of rows
per key value. An example of this would be that
for adverse events, a patient can have anywehre from 0
to 20 adverse events, each of which is a separate row
in the new dimensions.
foreign_tbl <- data.frame(id = 1:5) perkey_fun <- rep_per_key("id", tblnm = "foreign_tbl", 2, .6) perkey_fun(.db = list(foreign_tbl = foreign_tbl)) randrep_fun <- rand_per_key("id", tblnm = "foreign_tbl", mincount = 1, maxcount = 5) randrep_fun(.db = list(foreign_tbl = foreign_tbl))
foreign_tbl <- data.frame(id = 1:5) perkey_fun <- rep_per_key("id", tblnm = "foreign_tbl", 2, .6) perkey_fun(.db = list(foreign_tbl = foreign_tbl)) randrep_fun <- rand_per_key("id", tblnm = "foreign_tbl", mincount = 1, maxcount = 5) randrep_fun(.db = list(foreign_tbl = foreign_tbl))
Sample elements from x with replacing and build a factor
sample_fct(x, n, ...) sample_yn(n) rep_n(val, n, ...) seq_n(n, ...)
sample_fct(x, n, ...) sample_yn(n) rep_n(val, n, ...) seq_n(n, ...)
x |
character vector or factor, if character vector then it is also used as levels of the returned factor, otherwise if it is a factor then the levels get used as the new levels |
n |
number of observations to sample. |
... |
arguments passed on to |
val |
ANY. Single value to be repeated n times |
a factor of length N
sample_fct(letters[1:3], 10) sample_fct(iris$Species, 10) sample_yn(3) rep_n("aaa", 5) rep_n(1:5, 2) seq_n(10)
sample_fct(letters[1:3], 10) sample_fct(iris$Species, 10) sample_yn(3) rep_n("aaa", 5) rep_n(1:5, 2) seq_n(10)
Generate sequence of "subject id"s
subjid_func(n, prefix = "id", suffix = NULL, sep = "-")
subjid_func(n, prefix = "id", suffix = NULL, sep = "-")
n |
numeric(1). number of ids to generate. Values will be padded with leading 0s so all resulting ids have equal width |
prefix |
character(1). Prefix to prepend to the generated numeric ids. Defaults to |
suffix |
character(1). Suffix to append to generated ids. Defautls to |
sep |
character(1). String to use as separator when combining |
sequence from 1 to n
, prepended with prefix
, and appended with suffix
, separated by sep
subjid_func(5) subjid_func(3, suffix = "x")
subjid_func(5) subjid_func(3, suffix = "x")
Construct a table specification from one or more recipes
table_spec(data_rec, scaffold_rec = NULL, missing_rec = NULL)
table_spec(data_rec, scaffold_rec = NULL, missing_rec = NULL)
data_rec |
tibble. A recipe for the data of the table |
scaffold_rec |
tibble or NULL. A scaffolding join recipe. |
missing_rec |
tibble or NULL. A recipe for injecting missingness |
An object representing the collection of recipes corresponding this single table. Currently a named list.
Validate recipe for circular dependencies
validate_recipe_deps(recipe, seed_df = NULL)
validate_recipe_deps(recipe, seed_df = NULL)
recipe |
tibble. Table recipe. |
seed_df |
tibble. Seed/pre-existing data.frame or NULL. |
TRUE
if successful, throws an error if not