From f11c1fd56ac49a6fb0924f083715aba94eb4f836 Mon Sep 17 00:00:00 2001
From: Kamal Saleh <kamal.saleh@web.de>
Date: Fri, 7 Oct 2022 16:02:19 +0200
Subject: [PATCH] (1) add a method Random(r,c,ring,params) which makes

    constructing random matrices over singular more flexible

(2) change the hard coded parameters from

    RandomCombination( [ 0 .. 10 ], Random( [ 1 .. 11 ] ) )

    to

    [ 0, Random( [ 0, 1, 1, 1, 2, 2, 2, 3 ] ), 50, 80, 50 ]

    For polynomial and exterior rings
      - 0 is the minimal allowed degree
      - Random( [ 1, 1, 1, 2, 2, 2, 3 ] ) is the maximal allowd degree
      - 50% of the entries are zero
      - 80% of the terms in each entry are zero
      - The coefficient of each monomial is less than 50

(3) bump the version of MatricesForHomalg to 2022.10-04
---
 MatricesForHomalg/PackageInfo.g |  2 +-
 MatricesForHomalg/gap/Tools.gi  | 41 ++++++++++++++++++++++++++-------
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/MatricesForHomalg/PackageInfo.g b/MatricesForHomalg/PackageInfo.g
index b3748b8d6..75945a316 100644
--- a/MatricesForHomalg/PackageInfo.g
+++ b/MatricesForHomalg/PackageInfo.g
@@ -11,7 +11,7 @@ SetPackageInfo( rec(
 
 PackageName := "MatricesForHomalg",
 Subtitle := "Matrices for the homalg project",
-Version := "2022.10-03",
+Version := "2022.10-04",
 Date := Concatenation( "01/", ~.Version{[ 6, 7 ]}, "/", ~.Version{[ 1 .. 4 ]} ),
 License := "GPL-2.0-or-later",
 
diff --git a/MatricesForHomalg/gap/Tools.gi b/MatricesForHomalg/gap/Tools.gi
index bae1f1d4d..a4e14590c 100644
--- a/MatricesForHomalg/gap/Tools.gi
+++ b/MatricesForHomalg/gap/Tools.gi
@@ -4518,6 +4518,11 @@ InstallMethod( GetRidOfRowsAndColumnsWithUnits,
     
 end );
 
+##
+## L = [ min_deg, max_deg, zt, coeff ]
+## min_deg and max_deg determine the minimal and maximal degree of the element
+## zt determines the percentage of the zero terms in the element
+## The non-trivial coefficients belong to the interval [ 1 .. coeffs ]
 ##
 InstallMethod( Random,
         "for a homalg ring and a list",
@@ -4549,8 +4554,6 @@ InstallMethod( Random,
     
 end );
 
-if IsPackageMarkedForLoading( "utils", ">= 0.54" ) then
-
 ##
 InstallMethod( Random,
         "for a homalg ring",
@@ -4558,12 +4561,10 @@ InstallMethod( Random,
         
   function( R )
     
-    return Random( R, RandomCombination( [ 0 .. 10 ], Random( [ 1 .. 11 ] ) ) );
+    return Random( R, [ 0, Random( [ 0, 1, 1, 1, 2, 2, 2, 3 ] ), 80, 50 ] );
     
 end );
 
-fi;
-
 ##
 InstallMethod( Random,
         "for a homalg internal ring",
@@ -5087,6 +5088,30 @@ InstallMethod( RandomMatrix,
     
 end );
 
+##
+## params = [ min_deg,max_deg,ze,zt,coeffs ]
+##
+## min_deg and max_deg determine the minimal and maximal degree of an entry in the matrix
+## ze determines the percentage of the zero entries in the matrix (The default value is 50)
+## zt determines the percentage of the zero terms in each entry in the matrix (The default value is 80)
+## The non-trivial coefficients of each entry belong to the interval [ 1 .. coeffs ]  (The default value is 10)
+##
+InstallOtherMethod( RandomMatrix,
+        "for two integers, a homalg ring and a list",
+        [ IsInt, IsInt, IsHomalgRing, IsList ],
+  function( r, c, R, params )
+    local RP;
+    
+    RP := homalgTable( R );
+    
+    if IsBound(RP!.RandomMat) then
+        return HomalgMatrix( CallFuncList( RP!.RandomMat, Concatenation( [ R, r, c ], params ) ), r, c, R );
+    else
+        TryNextMethod();
+    fi;
+    
+end );
+
 ##
 InstallMethod( RandomMatrix,
         "for two integers and a homalg ring",
@@ -5104,11 +5129,11 @@ InstallMethod( RandomMatrix,
     
     RP := homalgTable( R );
     
-    if IsBound(RP!.RandomMat) and IsPackageMarkedForLoading( "utils", ">= 0.54" ) then
+    if IsBound(RP!.RandomMat) then
         
-        params := ValueGlobal( "RandomCombination" )( [ 0 .. 10 ], Random( [ 1 .. 11 ] ) );
+        params := [ 0, Random( [ 1, 1, 1, 2, 2, 2, 3 ] ), 50, 80, 50 ];
         
-        return HomalgMatrix( CallFuncList( RP!.RandomMat, Concatenation( [ R, r, c ], params ) ), r, c, R );
+        return RandomMatrix( r, c, R, params );
         
     fi;