mipfp (version 3.2.1)

ComputeA: Computes the marginal matrix A and margins vector m of an estimation problem

Description

Given a set of marginal target constraints and the dimension of the array \(X\) to wich the targets relate to, this function computes the matrix \(A\) of full rank and vector \(m\) such that $$A^T \pi = (m, 1)^T$$ where vector \(m\) contains all components but one of every target and \(\pi\) is a vector of the (unknow) components of \(X\).

Usage

ComputeA(dim.arr, target.list, target.data)

Arguments

dim.arr

The dimension of the array \(X\) to which the margins are applied.

target.list

A list of the target margins provided in target.data. Each component of the list is an array whose cells indicates which dimension the corresponding margin relates to.

target.data

A list containing the data of the target margins. Each component of the list is an array storing a margin. The list order must follow the one defined in target.list. Note that the cells of the arrays must be non-negative.

Value

A list whose elements are defined below.

marginal.matrix

The marginal matrix.

margins

A vector containing the margins associated with A.

df

The degree of freedom of the problem.

See Also

MarginalMatrix.

Examples

# NOT RUN {
# loading the data
data(spnamur, package = "mipfp")
# subsetting the data frame, keeping only the first 3 variables
spnamur.sub <- subset(spnamur, select = Household.type:Prof.status)
# true table
true.table <- table(spnamur.sub)
# extracting the margins
tgt.v1        <- apply(true.table, 1, sum)
tgt.v1.v2     <- apply(true.table, c(1,2), sum)
tgt.v2.v3     <- apply(true.table, c(2,3), sum)
tgt.list.dims <- list(1, c(1,2), c(2,3))
tgt.data      <- list(tgt.v1, tgt.v1.v2, tgt.v2.v3)
# creating the seed, a 10 pct sample of spnamur
seed.df <- spnamur.sub[sample(nrow(spnamur), round(0.10*nrow(spnamur))), ]
seed.table <- table(seed.df)
# computing the associated marginal matrix and margins vector
res.marg <- ComputeA(dim(seed.table), tgt.list.dims, tgt.data)
print(res.marg)
# }