import_survey: Import survey information from a file

In tmelliott/surveyspec: Survey Design Specification Format

Import survey information from a file

Description

The survey information should be in TOML format, with fields corresponding to survey design components. For example,

strata = strata_var
clusters = cluster_var
weights = wt_var

Usage

import_survey(file, data, read_fun, ...)

make_survey(.data, spec)

Arguments

file	the file containing survey information (see Details)
data	optional, if supplied the survey object will be created with the supplied data. Can be either a data.frame-like object, or a path to a data set which will be imported using iNZightTools::smart_read.
read_fun	function required to load the data specified in file
...	additional arguments to read_fun
.data	a data.frame
spec	a inzsvyspec object

Details

For replicate weight designs, vectors (if necessary) are declared with square brackets, like so:

repweights = ['w01', 'w02', 'w03', 'w04', ..., 'w20']

although this would be better expressed using a regular expression,

repweights = '^w[0-2]'

which matches all variables starting with a w followed by digits between 0 and 2 (inclusive).

Additionally, the information can contain a file specification indicating the path to the data, which will be imported (if it exists in the same directory as file) using read_fun, if specified; or alternatively file can be a URL to a data file that will be downloaded and read, again using read_fun.

If the data is not specified to import_survey, then make_survey can be used to manually construct an inzsvyspec object with the design attached. This might be useful if you have multiple datasets with the same design, for example.

import_survey calls make_survey when data is provided.

Value

a inzsvyspec object containing the design parameters and, if data supplied, the created survey object. The object is a list containing at least a 'spec' component, and if data is supplied then also 'data' and 'design' components.

Functions

• import_survey(): Import survey information from a file

• make_survey(): Construct a survey object from a data set and an inzsvyspec object

Specification format

The survey design specification file used by 'surveyspec' should be in TOML format. This allows for a very human-readable syntax,

arg = "value"

and additionally some additional complexity where needed (for example when specifying calibration information).

For stratified and clustering samples, each argument to survey::svydesign can be given on its own line. So for a stratified sample using the apistrat data from the 'survey' package, the following specification would suffice:

strata = "stype"
weights = "pw"
fpc = "fpc"

For a cluster sample, we instead can provide either clusters or ids (the former makes it more obvious to beginners, while the latter is consistent with svydesign()). For example, specifying the design for the apiclus2 data:

clusters = "dnum + snum"
fpc = "fpc1 + fpc2"

Alternatively, survey data may be distributed with replicate weights. To specify this information to import_survey(), the same concept is used but the arguments supplied should be based off those used in survey::svrepdesign(). For example (taken from ?svrepdesign):

weights = "pw"
repweights = "wt[1-9]+"
type = "JK1"
scale = "~(1-15/757)*14/15"
combined = FALSE

Note here that you can specify an expression for scale, but need to use this syntax, "~expr", for it to be parsed correctly.

Finally, survey design calibration can be performed by including this information using TOML list syntax. For example, to calibrate the 'apistrat' data,

strata = "stype"
weights = "pw"
fpc = "fpc"

[calibrate.stype]
E = 4421
H = 755
M = 1018

[calibrate."sch.wide"]
"No" = 1072
"Yes" = 5122

Note importantly the use of quotes around variable names which include a period (.), here sch.wide. Currently, only calibrating by a factor is possible.

Examples

library(survey)
data(api)
dstrat <- svydesign(ids = ~1, strata = ~stype, weights = ~pw,
 fpc = ~fpc, data = apistrat)

f <- tempfile(fileext = ".svydesign")
write_spec(dstrat, f)

cat(readLines(f), sep = "\n")

(spec <- import_survey(f))
(svy <- make_survey(apistrat, spec))

# or all in one:
(svy <- import_survey(f, data = apistrat))

tmelliott/surveyspec documentation built on Dec. 1, 2022, 10 p.m.