dfMergeVariablesRelevel

Merge variables in a data frame such as returned by dbGetFieldsIntoDf
into a new variable, and optionally also map its values to new levels.

A system for querying, retrieving and analyzing
protocol- and results-related information on clinical trials from
four public registers, the 'European Union Clinical Trials Register'
('EUCTR', <https://www.clinicaltrialsregister.eu/>),
'ClinicalTrials.gov' ('CTGOV', using the classic interface at
<https://classic.clinicaltrials.gov/>, and 'CTGOV2', using the
current interface at <https://www.clinicaltrials.gov/>), the
'ISRCTN' (<http://www.isrctn.com/>) and the
'European Union Clinical Trials Information System'
('CTIS', <https://euclinicaltrials.eu/>).
Trial information is downloaded, converted and stored in a database
('PostgreSQL', 'SQLite', 'DuckDB' or 'MongoDB'; via package 'nodbi').
Documents in registers associated with trials can also be downloaded.
Other functions identify deduplicated records,
easily find and extract variables (fields) of interest even
from complex nested data as used by the registers,
merge variables and update queries.
The package can be used for meta-analysis and trend-analysis of
the design and conduct as well as of the results of clinical trials.

Ralf Herold

ctrdata

Retrieve and Analyze Clinical Trials in Public Registers

dfMergeVariablesRelevel function

<dl><dt>df</dt>
<dd>A <a href="/link/data.frame?package=ctrdata&version=1.16.0" data-mini-rdoc="ctrdata::data.frame">data.frame</a> with the variables (columns) to be merged into
one vector.</dd>
<dt>colnames</dt>
<dd>A vector of names of columns in `df` that hold the variables
to be merged, or a selection of columns as per <code><a href="https://dplyr.tidyverse.org/reference/select.html">select</a></code>.</dd>
<dt>levelslist</dt>
<dd>A names list with one slice each for a new value to be
used for a vector of old values (optional).</dd></dl>

Arguments

Merge variables, keeping type, and optionally relevel factors — dfMergeVariablesRelevel

<dl>

<dt>df</dt>
<dd>A <a href='https://rdrr.io/r/base/data.frame.html'>data.frame</a> with the variables (columns) to be merged into
one vector.</dd>


<dt>colnames</dt>
<dd>A vector of names of columns in `df` that hold the variables
to be merged, or a selection of columns as per <code><a href='https://dplyr.tidyverse.org/reference/select.html'>select</a></code>.</dd>


<dt>levelslist</dt>
<dd>A names list with one slice each for a new value to be
used for a vector of old values (optional).</dd>

</dl>

dfMergeVariablesRelevel: Merge variables, keeping type, and optionally relevel factors

Description

Usage

Value

Arguments

Examples