isIndexedMatrix

isIndexedMatrix(X)

X is a matrix.

Determine if X is an indexed matrix.

m=matrix(1..10, 11..20)
m.rename!(2020.01.01..2020.01.10, `A`B);

isIndexedMatrix(m);
// output
false

m.setIndexedMatrix!()
isIndexedMatrix(m);
// output
true