"missing" unused argument in chromatorgram()

[arebruvold]

Missing is not a valid argument for xcms::chromatorgram(), although it should be as per the documentation. Neither is it an argument in MSnbase.

[jorainer]

Note: missing is an argument for the chromatogram() method for xcms::XCMSnExp - but not for XcmsExperiment (see documentation). Missing data points are now represented by a NA intensity value - which is also the default for chromatogram,XCMSnExp. Changing the intensity of missing peaks to a non-NA value seems counterintuitive.