| unListDS {dsBase} | R Documentation |
this function is based on the native R function unlist which coerces an object of list class back to the class it was when it was coerced into a list
unListDS(x.name)
x.name |
the name of the input object to be unlisted. It must be specified in inverted commas e.g. x.name="input.object.name". Fully specified by the <x.name> argument of ds.unList |
See details of the native R function unlist. This function represents a substantive restructuring of an earlier version created by Amadou Gaye. For further details of its working please see 'details' in the help for ds.unList.
the object specified by the <newobj> argument of the ds.unList function (or by default <x.name>.unlist if the <newobj> argument is NULL). This is written to the serverside. As well as writing the output object as <newobj> on the serverside, two validity messages are returned indicating whether <newobj> has been created in each data source and if so whether it is in a valid form. If its form is not valid in at least one study - e.g. because a disclosure trap was tripped and creation of the full output object was blocked - ds.seq() also returns any studysideMessages that can explain the error in creating the full output object. As well as appearing on the screen at run time,if you wish to see the relevant studysideMessages at a later date you can use the ds.message function. If you type ds.message("<newobj>") it will print out the relevant studysideMessage from any datasource in which there was an error in creating <newobj> and a studysideMessage was saved. Because the outcome object from ds.unList is typically a list object with no names, if there are no errors in creating it the message returned from ds.message("<newobj>") in each study will read "Outcome object is a list without names. So a studysideMessage may be hidden. Please check output is OK". This suggests that - in the case of this specific function - one should check as far as one can the nature of the output from a call to ds.unList - e.g. ds.class, ds.length etc
Amadou Gaye (2016), Paul Burton (19/09/2019) for DataSHIELD Development Team