#### D.4.25.22 normaliz

Procedure from library `normaliz.lib` (see normaliz_lib).

Return:
  The function applies Normaliz to the matrix input_mat ofe type nmz_type. One can add further pairs "value, type" such as vectors or numerical parameters. See Normaliz manual for possible types and values. The function returns the intmat defined by the file ith suffix gen, provided it has been computed. Otherwise it returns the input_mat.

Note:
  You will find procedures for many applications of Normaliz in this library, so the explicit call of this procedure may not be necessary.

  The function reads the numerical invariants computed by normaliz. The integers among them are converted to the Singular type int. It may to bee too small for the Hilbert function or the multiplicity, especially if computed for a non-standard grading. To prevent a disaster set the predefined global variable BigNumInvs = 1. Returnung to BigNumInvs = 0 switches this feature off.

Example:

    LIB "normaliz.lib";
    ring R=0,(x,y,z),dp;
    intmat M[3][2]=3,1,
    3,2,
    1,3;
    normaliz(M,"cone");
    ==> 1,1,
    ==> 1,2,
    ==> 1,3,
    ==> 2,1,
    ==> 3,1
    intmat Inequalities[2][3] = 2,-1,0, // 2x-y >= 0
    1, 1,0; //  x+y >= 0
    intmat Equation[1][3] = 0,1,-1;    // y = z
    intmat Congruence[1][4] = 1,0,0,3;  // x = 0 (3)
    normaliz(Inequalities,"inequalities",Equation,"equations",Congruence,"congruences");
    ==> 3,-3,-3,
    ==> 3,-2,-2,
    ==> 3,-1,-1,
    ==> 3,0,0,
    ==> 3,1,1,
    ==> 3,2,2,
    ==> 3,3,3,
    ==> 3,4,4,
    ==> 3,5,5,
    ==> 3,6,6

See also: diagInvariants; ehrhartRing; finiteDiagInvariants; intclMonIdeal; intclToricRing; intersectionValRingIdeals; intersectionValRings; normalToricRing; torusInvariants.

User manual for Singular version 4.4.1, 2025, generated by texi2html.