ds.matrixDet.report {dsBaseClient}R Documentation

ds.matrixDet.report calling aggregate function matrixDetDS1

Description

Calculates the determinant of a square matrix A and returns the result to the clientside

Usage

ds.matrixDet.report(M1 = NULL, logarithm = FALSE, datasources = NULL)

Arguments

M1

A character string specifying the name of the matrix for which determinant to be calculated

logarithm

logical. Default is FALSE, which returns the determinant itself, TRUE returns the logarithm of the modulus of the determinant.

datasources

specifies the particular opal object(s) to use. If the <datasources> argument is not specified the default set of opals will be used. The default opals are called default.opals and the default can be set using the function ds.setDefaultOpals. If the <datasources> is to be specified, it should be set without inverted commas: e.g. datasources=opals.em or datasources=default.opals. If you wish to apply the function solely to e.g. the second opal server in a set of three, the argument can be specified as: e.g. datasources=opals.em[2]. If you wish to specify the first and third opal servers in a set you specify: e.g. datasources=opals.em[c(1,3)]

Details

Calculates the determinant of a square matrix (for additional information see help for determinant function in native R). This operation is only possible if the number of columns and rows of A are the same.

Value

the matrix determinant for A to the clientside. Calculated separately for each study. The determinant is reported as a two component list. Element 1 is $modulus and element 2 is $sign. If logarithm=FALSE: $modulus reports the absolute value of the determinant and is therefore always positive. $sign indicates whether the determinant is positive ($sign=1) or negative ($sign=-1). $modulus has an attribute [attr(,"logarithm")] which is FALSE if the argument <logarithm> was FALSE - this enables you to look at results post-hoc to determine whether the logarithm argument was TRUE or FALSE. If you wish to generate the actual determinant if logarithm=FALSE it is easiest to calculate $modulus*$sign. If logarithm=TRUE: $modulus reports the log (to base e) of the absolute value of the determinant. $sign again reports whether the determinant is positive ($sign=1) or negative ($sign=-1). The attribute of $modulus [attr(,"logarithm")] is now TRUE. If you wish to generate the actual determinant when logarithm=TRUE you calculate exp($modulus)*$sign. If the function fails in any study for a reason which is identified, an explanatory error message is returned instead of the object containing the calculated matrix determinant

Author(s)

Paul Burton for DataSHIELD Development Team


[Package dsBaseClient version 5.0.0 ]