pubmedR (version 1.0.2)

pmQueryTotalCount: Count the number of documents returned by a query

Description

It counts the number of documents that a query returns from the NCBI PubMed database.

Usage

pmQueryTotalCount(query, api_key = NULL)

Value

a list. It contains three objects:

total_count		The total number of records returned by the query
query_translation		The query translation by the NCBI Automatic Terms Translation system
web_history		The web history object. The NCBI provides search history features, which is useful for dealing with large lists of IDs or repeated searches.

To obtain a free access to NCBI API, please visit: https://pmc.ncbi.nlm.nih.gov/tools/developers/

Arguments

query

is a character. It contains a search query formulated using the Entrez query language.

api_key

is a character. It contains a valid API key for the NCBI E-utilities. Default is api_key=NULL. The use of NCBI PubMed APIs is entirely free, and doesn't necessarily require an API key. The API key can also be set via the environment variable PUBMED_API_KEY or ENTREZ_KEY.

See Also

pmApiRequest

pmApi2df

Examples

# \donttest{
query <- "bibliometric*[Title/Abstract] AND english[LA]
           AND Journal Article[PT] AND 2000:2020[DP]"
D <- pmQueryTotalCount(query = query, api_key = NULL)
# }