added another way to call minimalPolynomial

NumberFields/KarlsTestingFile.m2

@@ -53,16 +53,24 @@ restart
 
 loadPackage "NumberFields"
 S = QQ[a,b,c]/ideal(a^3-2, a^2+a*b+b^2, sum(apply(11, t->c^t)))
+T = QQ[a,b]/ideal(a^3-2, a^2+a*b+b^2)
+psi = map(S, T)
 R = time numberField(S)
 minimalPolynomial( sum gens S)
 minimalPolynomial( (gens R)#0)
 minimalPolynomial( sum gens R)
+minimalPolynomial( c, psi)
 
 time simpleExt(R);
 time simpleExt(R, Strategy=>kernel);
 time simpleExt(R, Strategy=>null);
 time simpleExt(R, Strategy=>minimalPolynomial);
 
+S = QQ[x]/ideal(x^2+1)
+T = QQ[y]/ideal(y^4+1)
+psi = map(T, S, {y^2})
+minimalPolynomial(y, psi)
+
 
 -----------------
 --Karl testing isFieldAutomorphism

NumberFields/NumberFields.m2

@@ -655,6 +655,39 @@ minimalPolynomial(RingElement) := opts -> (f1) -> (--we should only compute the
  (entries (M1*(gens(kernel(A1)))))#0#0
 )
 
+minimalPolynomial(RingElement, RingMap) := opts -> (f1, psi1) -> (--this finds the minimal polynomial of an element f1 in L1, where the second argument is a field extension K1 -> L1 
+ --
+ R1 := ring f1; 
+ R2 := target psi1;
+ if not (R1 === R2) then error "minimalPolynomial: expected the target of the map to agree with the ring of the source";
+ C1 := source psi1;
+ D := (degree R1)/ (degree C1);
+ local y;
+ if (opts.Variable === null) then (y = local xx;) else (y = opts.Variable); 
+ --y := local aa;
+ S1 := C1[y];
+ y = (gens S1)#0;
+ P1 := pushFwd(psi1);
+ A1 := (P1#2)(1_R1);
+ curf1 := 1;
+ pow1 := 1;
+ --while (gens(kernel(A1))==0) do (
+ while ((pow1 == 1) and (gens(kernel(A1))==0)) or (D%(pow1-1) != 0) or (gens(kernel(A1))==0) do (
+ if (debugLevel > 1) then print pow1;
+ pow1 += 1;
+ curf1=curf1*f1;
+ --A1 = A1|(P1#2)(f1^pow1);
+ A1 = A1|(P1#2)(curf1);
+ if (pow1 > D+1) then error "minimalPolyommial: something went wrong, is this a field?";
+ );
+ pow1 = pow1-1;
+ M1 := matrix({{1_S1}});
+ for i1 from 1 to (pow1) do (
+ M1 |= y^i1;
+ );
+ (entries (M1*(gens(kernel(A1)))))#0#0
+)
+
 minimalPolynomial(List) := opts -> L1 -> (
  apply(L1, i -> minimalPolynomial(i))
 )