matrix Phi
This is equivalent to matrix map Phi. Moreover, the command matrix Phi is equivalent to matrix(0,Phi), and more generally the command matrix(i,Phi) returns the matrix of the i-th representative of Phi.
The source of this document is in /build/reproducible-path/macaulay2-1.25.05+ds/M2/Macaulay2/packages/Cremona/documentation.m2:729:0.