D.5.9.6 qhmatrix

Procedure from library spcurve.lib (see spcurve_lib).

Usage:

qhmatrix(M); M a k x (k+1) matrix

Return:

list, consisting of an integer vector containing the weights of the variables of the basering and an integer matrix giving the weights of the entries of M, if M is quasihomogeneous; zero integer vector and zero integer matrix, if M is not quasihomogeneous, i.e. does not allow row and column weights

Example:

LIB "spcurve.lib";
ring r=0,(x,y,z),ds;
matrix M[3][2]=z,0,y,x,x^3,y;
qhmatrix(M);
→ [1]:
→    1,2,1
→ [2]:
→    1,0,
→    2,1,
→    3,2 
pmat(M);
→ z,  0, 
→ y,  x, 
→ x3, y