Converts the standard plpData to a sparse matrix
toSparseM(plpData, cohort = NULL, map = NULL)
An object of type plpData
with covariate in coo format - the patient level prediction
data extracted from the CDM.
If specified the plpData is restricted to the rowIds in the cohort (otherwise plpData$labels is used)
A covariate map (telling us the column number for covariates)
Returns a list, containing the data as a sparse matrix, the plpData covariateRef and a data.frame named map that tells us what covariate corresponds to each column This object is a list with the following components:
A sparse matrix with the rows corresponding to each person in the plpData and the columns corresponding to the covariates.
The plpData covariateRef.
A data.frame containing the data column ids and the corresponding covariateId from covariateRef.
This function converts the covariate file from ffdf in COO format into a sparse matrix from the package Matrix
#TODO