getMQPARValue: Retrieve a parameter value from a mqpar.xml file

In PTXQC: Quality Report Generation for MaxQuant and mzTab Results

Retrieve a parameter value from a mqpar.xml file

Description

If the file has the param, then return it as string. If the file is missing, warning is shown and NULL is returned. If the param (i.e. XML tag) is unknown or cannot be extracted, the program will quit (since this is a hard error). When multiple occurrences of the param are found (usually due to parameter groups), we test if the values are all identical. If so, the value is returned. If the values are different, a warning is emitted and NULL is returned unless 'allow_multiple = TRUE'

Usage

getMQPARValue(mqpar_filename, xpath, allow_multiple = FALSE)

Arguments

mqpar_filename	Filename (incl. absolute or relative path) to the mqpar.xml file
xpath	An XPath to extract the content of XML tag(s), e.g. '//firstSearchTol'
allow_multiple	If the XPath expression returns more than one value, all values must be identical (not allowing multiple different values) or 'stop()' is called

Details

E.g. calling getMQPARValue("mqpar.xml", "//firstSearchTol") will look up the line <firstSearchTol>20</firstSearchTol> and return "20" (string!).

Value

The stored value as string(!)

PTXQC documentation built on May 29, 2024, 9:26 a.m.