nhanesA (version 1.3)

nhanesFromURL: Download NHANES table from URL

Description

Downloads an NHANES table from a URL and returns it as a data frame.

Usage

nhanesFromURL(
  url,
  translated = TRUE,
  cleanse_numeric = TRUE,
  nchar = 128,
  adjust_timeout = TRUE
)

Value

A data frame containing the data in the XPT file avalable at the URL.

Arguments

url

URL of XPT file to be downloaded.

translated

logical, whether variable codes should be translated

cleanse_numeric

Logical flag. If TRUE, some special codes in numeric variables, such as ‘Refused’ and ‘Don't know’ will be converted to NA.

nchar

integer, labels are truncated after this

adjust_timeout

Typically a logical flag indicating whether the default download.file timeout option should be adjusted by taking into account the size of the file to be downloaded, as reported by the server. The value can also be a positive numeric value, in which case it is used as a further multiplicative factor for the default calculation.

Details

This function downloads a table from the NHANES website using its URL. It is similar to nhanes, except that it requires the URL to be explicitly specified, and does not try to infer it from the table name. It also performs some limited cleansing of the data by default.

The URL may be completely specified, but the initial standard prefix "https://wwwn.cdc.gov" may be optionally dropped. More precisely, if the URL starts with "/nchs/", then the prefix is automatically added. It is possible to override the default prefix by setting the environment variable NHANES_TABLE_BASE (this allows the use of a local or alternative mirror of the CDC data).

Examples

vix_e = nhanesFromURL("https://wwwn.cdc.gov/Nchs/Data/Nhanes/Public/2007/DataFiles/VIX_E.xpt")
bpx_e = nhanesFromURL("/Nchs/Data/Nhanes/Public/2007/DataFiles/BPX_E.xpt", translated = FALSE)
dim(bpx_e)