ds.dmtC2S: Copy a clientside data.frame, matrix or tibble to the...

View source: R/ds.dmtC2S.R

ds.dmtC2SR Documentation

Copy a clientside data.frame, matrix or tibble to the serverside


Creates a data.frame, matrix or tibble on the serverside that is equivalent to that same data.frame, matrix or tibble (DMT) on the clientside.


ds.dmtC2S(dfdata = NA, newobj = NULL, datasources = NULL)



is a character string that specifies the name of the DMT to be copied from the clientside to the serverside


A character string specifying the name of the DMT on the serverside to which the output is to be written. If no <newobj> argument is specified or it is NULL the name of the copied DMT defaults to "dmt.copied.C2S".


specifies the particular 'connection object(s)' to use. e.g. if you have several data sets in the sources you are working with called opals.a, opals.w2, and connection.xyz, you can choose which of these to work with. The call 'datashield.connections_find()' lists all of the different datasets available and if one of these is called 'default.connections' that will be the dataset used by default if no other dataset is specified. If you wish to change the connections you wish to use by default the call datashield.connections_default('opals.a') will set 'default.connections' to be 'opals.a' and so in the absence of specific instructions to the contrary (e.g. by specifiying a particular dataset to be used via the <datasources> argument) all subsequent function calls will be to the datasets held in opals.a. If the <datasources> argument is specified, it should be set without inverted commas: e.g. datasources=opals.a or datasources=default.connections. The <datasources> argument also allows you to apply a function solely to a subset of the studies/sources you are working with. For example, the second source in a set of three, can be specified using a call such as datasources=connection.xyz[2]. On the other hand, if you wish to specify solely the first and third sources, the appropriate call will be datasources=connections.xyz[c(1,3)]


ds.dmtC2S calls assign function dmtC2SDS. To keep the function simple (though less flexible), a number of the parameters specifying the DMT to be generated on the serverside are fixed by the characteristics of the DMT to be copied rather than explicitly specifying them as selected arguments. In consequence, they have been removed from the list of arguments and are instead given invariant values in the first few lines of code. These include: from="clientside.dmt", nrows.scalar=NULL, ncols.scalar=NULL, byrow = FALSE. The specific value "clientside.dmt" for the argument <from> simply means that the required information is generated from the characteristics of a clientside DMT. The <nrows.scalar> and <ncols.scalar> are fixed empirically by the number of rows and columns of the DMT to be copied. <byrow> specifies writing the serverside DMT by columns or by rows and this is defaulted to byrow=FALSE i.e. "by column".


the object specified by the <newobj> argument (or default name "dmt.copied.C2S") which is written as a data.frame/matrix/tibble to the serverside.


Paul Burton for DataSHIELD Development Team - 3rd June, 2021

datashield/dsBaseClient documentation built on April 19, 2022, 5:25 a.m.