ENHANCE: RandomUnimodularMat allows for option of entry range

as Random(Integers) only selects from [-10..10].

lib/matrix.gd

@@ -1671,17 +1671,23 @@ DeclareGlobalFunction( "RandomMat" );
 ##
 ## <#GAPDoc Label="RandomUnimodularMat">
 ## <ManSection>
-## <Func Name="RandomUnimodularMat" Arg='[rs ,] m'/>
+## <Func Name="RandomUnimodularMat" Arg='[rs ,] m [:random:=d]'/>
 ##
 ## <Description>
 ## returns a new random mutable <A>m</A><M>\times</M><A>m</A> matrix with integer
 ## entries that is invertible over the integers.
-## Optionally, a random source <A>rs</A> can be supplied.
+## Optionally, a random source <A>rs</A> can be supplied. If the
+## option <C>random</C> is given, selection of random numbers is made from
+## <A>d</A> (allowing for larger coefficients), otherwise from 
+## <Ref Var="Integers"/> (for which random selection is bounded).
 ## <Example><![CDATA[
 ## gap> m := RandomUnimodularMat(3);
 ## [ [ -5, 1, 0 ], [ 12, -2, -1 ], [ -14, 3, 0 ] ]
 ## gap> m^-1;
 ## [ [ -3, 0, 1 ], [ -14, 0, 5 ], [ -8, -1, 2 ] ]
+## gap> m := RandomUnimodularMat(3:random:=[-100..100]);
+## [ [ -2795335, 8733, 6466434 ], [ -19667053, 61444, 45495692 ],
+## [ 37158478, -116088, -85958515 ] ]
 ## ]]></Example>
 ## </Description>
 ## </ManSection>

lib/matrix.gi

@@ -3651,8 +3651,13 @@ end );
 #F RandomUnimodularMat( [rs ,] <m> ) . . . . . . . random unimodular matrix
 ##
 InstallGlobalFunction( RandomUnimodularMat, function ( arg )
- local rs, m, mat, c, i, j, k, l, a, b, v, w, gcd;
+local rs, m, mat, c, i, j, k, l, a, b, v, w, gcd,dom;
 
+ dom:=ValueOption("random");
+ if dom=fail or dom=false then
+ dom:=Integers;
+ fi;
+
  if Length(arg) >= 1 and IsRandomSource(arg[1]) then
  rs := Remove(arg, 1);
  else
@@ -3684,8 +3689,8 @@ InstallGlobalFunction( RandomUnimodularMat, function ( arg )
  j := Random(rs, [1..m]);
  until j <> i;
  repeat
- a := Random( rs, Integers );
- b := Random( rs, Integers );
+ a := Random( rs, dom );
+ b := Random( rs, dom );
  gcd := Gcdex( a, b );
  until gcd.gcd = 1;
  v := mat[i]; w := mat[j];
@@ -3698,8 +3703,8 @@ InstallGlobalFunction( RandomUnimodularMat, function ( arg )
  l := Random(rs, [1..m]);
  until l <> k;
  repeat
- a := Random( rs, Integers );
- b := Random( rs, Integers );
+ a := Random( rs, dom );
+ b := Random( rs, dom );
  gcd := Gcdex( a, b );
  until gcd.gcd = 1;
  for i in [1..m] do