
// Make newform 2300.2.a.o in Magma, downloaded from the LMFDB on 25 April 2024.
// To make the character of type GrpDrchElt, type "MakeCharacter_2300_a();"
// To make the coeffs of the qexp of the newform in the Hecke field type "qexpCoeffs();"
// To make the newform (type ModFrm), type "MakeNewformModFrm_2300_2_a_o();".
// This may take a long time!  To see verbose output, uncomment the SetVerbose lines below.
// The precision argument determines an initial guess on how many Fourier coefficients to use.
// This guess is increased enough to uniquely determine the newform.
// To make the Hecke irreducible modular symbols subspace (type ModSym)
// containing the newform, type "MakeNewformModSym_2300_2_a_o();".
// This may take a long time!  To see verbose output, uncomment the SetVerbose line below.
// The default sign is -1.  You can change this with the optional parameter "sign".
function ConvertToHeckeField(input: pass_field := false, Kf := [])
    if not pass_field then
        poly := [-1, -6, 22, 0, -12, 0, 1];
        Kf := NumberField(Polynomial([elt : elt in poly]));
        AssignNames(~Kf, ["nu"]);
    end if;
    Rf_num := [[1, 0, 0, 0, 0, 0], [-27, -3, 33, 11, -3, -1], [-7, 41, -11, -33, 1, 3], [43, -157, -25, 85, 3, -7], [11, 195, -41, -107, 3, 9], [53, -179, 25, 107, -3, -9]];
    Rf_basisdens := [1, 8, 8, 16, 16, 16];
    Rf_basisnums := ChangeUniverse([[z : z in elt] : elt in Rf_num], Kf);
    Rfbasis := [Rf_basisnums[i]/Rf_basisdens[i] : i in [1..Degree(Kf)]];
    inp_vec := Vector(Rfbasis)*ChangeRing(Transpose(Matrix([[elt : elt in row] : row in input])),Kf);
    return Eltseq(inp_vec);
end function;


// To make the character of type GrpDrchElt, type "MakeCharacter_2300_a();"
function MakeCharacter_2300_a()
    N := 2300;
    order := 1;
    char_gens := [1151, 277, 1201];
    v := [1, 1, 1];
    // chi(gens[i]) = zeta^v[i]
    assert UnitGenerators(DirichletGroup(N)) eq char_gens;
    F := CyclotomicField(order);
    chi := DirichletCharacterFromValuesOnUnitGenerators(DirichletGroup(N,F),[F|F.1^e:e in v]);
    return MinimalBaseRingCharacter(chi);
end function;

function MakeCharacter_2300_a_Hecke(Kf)
    return MakeCharacter_2300_a();
end function;


function ExtendMultiplicatively(weight, aps, character)
    prec := NextPrime(NthPrime(#aps)) - 1; // we will able to figure out a_0 ... a_prec
    primes := PrimesUpTo(prec);
    prime_powers := primes;
    assert #primes eq #aps;
    log_prec := Floor(Log(prec)/Log(2)); // prec < 2^(log_prec+1)
    F := Universe(aps);
    FXY<X, Y> := PolynomialRing(F, 2);
    // 1/(1 - a_p T + p^(weight - 1) * char(p) T^2) = 1 + a_p T + a_{p^2} T^2 + ...
    R<T> := PowerSeriesRing(FXY : Precision := log_prec + 1);
    recursion := Coefficients(1/(1 - X*T + Y*T^2));
    coeffs := [F!0: i in [1..(prec+1)]];
    coeffs[1] := 1; //a_1
    for i := 1 to #primes do
        p := primes[i];
        coeffs[p] := aps[i];
        b := p^(weight - 1) * F!character(p);
        r := 2;
        p_power := p * p;
        //deals with powers of p
        while p_power le prec do
            Append(~prime_powers, p_power);
            coeffs[p_power] := Evaluate(recursion[r + 1], [aps[i], b]);
            p_power *:= p;
            r +:= 1;
        end while;    
    end for;
    Sort(~prime_powers);
    for pp in prime_powers do
        for k := 1 to Floor(prec/pp) do
            if GCD(k, pp) eq 1 then
                coeffs[pp*k] := coeffs[pp]*coeffs[k];
            end if;
        end for;
    end for;
    return coeffs;
end function;


function qexpCoeffs()
    // To make the coeffs of the qexp of the newform in the Hecke field type "qexpCoeffs();"
    weight := 2;
    raw_aps := [[0, 0, 0, 0, 0, 0], [1, 0, 1, 0, 0, 0], [0, 0, 0, 0, 0, 0], [2, 0, 0, -1, 0, 0], [1, 0, -1, 0, 1, -1], [1, 1, -1, 1, 1, 0], [1, 0, -1, 0, 0, -1], [1, 0, 1, -1, 0, 1], [1, 0, 0, 0, 0, 0], [2, 0, 2, 0, 0, -1], [0, 1, 0, 1, -1, 1], [2, 0, 0, -1, -2, 2], [0, -1, 2, -1, -1, 1], [1, 0, 1, 1, -2, 1], [3, -1, 1, 1, 1, 0], [1, -1, -1, -2, 0, -1], [-3, -2, 1, -1, -3, 1], [1, 0, -1, 1, 2, -3], [4, 0, -2, 1, 2, 0], [-4, 2, -2, 2, 0, -1], [-3, -2, 1, 0, 0, 2], [1, 0, 1, 1, 0, 1], [3, 2, -3, 2, 0, -3], [-5, -2, -3, 1, 2, 1], [1, -3, 1, -1, -2, -1], [-1, 3, -1, 2, 0, 1], [10, 1, -2, 0, 2, -4], [4, 1, -2, 1, 2, 2], [1, -2, -1, -3, 0, -1], [-4, 0, -2, 1, 0, -2], [5, 0, -3, 2, 2, -2], [-3, 1, -3, -2, -2, 0], [2, 0, 2, 0, 0, 2], [-4, 0, -6, 0, 0, -3], [-4, -2, -2, 2, -2, -2], [-7, -2, -1, 1, 1, 4], [8, 1, 6, -1, 0, 0], [3, -2, -1, 2, 0, 0], [-2, -3, 0, 1, -1, -2], [-8, -1, 2, -3, -3, 2], [-3, -2, -1, -1, 1, 2], [-1, -2, -1, -4, -5, 1], [-4, 0, -6, -1, 1, -4], [-1, 0, 3, 2, 0, 0], [-1, -2, -1, 0, -2, 4], [3, 4, -3, 2, 3, -3], [7, 1, -3, 2, 0, -3], [6, -4, -2, 0, 2, 0], [-3, 3, -3, 1, -2, -1], [-5, -2, 1, 1, 0, 1], [-5, 2, -1, -2, -2, 4], [-2, 1, 6, -1, -5, 3], [2, -2, -6, 1, 1, 2], [-2, 0, 0, 3, -1, 0], [-5, 1, 1, 1, 5, -4], [-4, -3, -2, 1, -4, 2], [0, 1, -2, 1, 1, 5], [-3, -1, 3, 0, -4, 1], [5, -3, 7, -1, -1, 0], [-13, 0, -1, 4, 3, 3], [19, -2, 1, -2, 0, -1], [1, 1, -1, -4, 2, -3], [2, 3, 0, -1, -5, 2], [3, -4, 1, -3, 1, 4], [-5, 1, -7, 2, 6, -1], [2, -1, 8, 1, 5, 0], [-6, -4, 4, -2, 0, 1], [-5, 4, -5, 5, 2, -5], [-8, 0, 0, -2, 0, 6], [2, -3, 4, 1, 3, 1], [-3, 4, -3, -2, 2, -2], [9, 0, 9, -3, 0, -3], [3, 2, 5, -2, -2, 1], [0, 5, 0, -4, -4, 0], [2, -2, 2, 0, 0, 2], [0, 1, 2, -1, -4, 0], [-4, 0, -6, 6, -2, 0], [-5, -3, 5, -1, -3, 8], [12, 4, -4, -3, -1, -4], [0, -1, 2, -1, -3, -1], [1, 2, -3, -1, 0, -5], [-5, 0, 3, -4, 1, -1], [-7, 2, -3, 1, 0, -1], [9, 2, -1, 6, 4, -3], [-13, -1, 7, 4, -2, 6], [-13, 1, 5, 1, -3, 2], [3, 0, 1, -1, -5, 3], [-25, 4, -3, 2, 2, 1], [3, 3, 1, -2, 4, 2], [10, -4, 2, -4, 0, -4], [-1, 3, 5, -6, -2, 1], [8, 0, 6, -3, 5, 2], [5, -1, 11, 3, -1, 6], [18, -4, 0, -6, 0, 3], [-6, -3, 2, 3, 7, 1], [-3, 1, -9, 6, 6, 3], [11, -3, 1, -4, -2, -2], [-14, -2, 0, 6, -2, -2], [7, 3, -9, -1, -2, -3], [15, 2, -1, 3, 3, -4], [15, 1, 5, -5, -1, -6], [-10, -1, -8, 7, 0, -2], [5, -1, 3, 2, 4, 5], [-4, 0, 4, -3, -7, 4], [-14, 8, -4, 3, 3, -4], [-9, 3, 5, -5, -3, 2], [-11, -6, 5, -6, -10, 6], [0, 2, 4, 0, 4, -6], [4, 3, -2, -7, -3, 0], [6, -6, 2, 0, -4, 3], [18, 3, 8, -3, 3, 4], [10, -3, -2, -2, 2, 0], [-10, 3, 12, -1, -4, 4], [-8, 2, -8, 2, 0, -8], [3, 0, -5, 9, -2, -3], [1, 0, -9, -3, -2, -5], [9, 0, -1, -4, -2, 5], [11, 0, -1, -8, -2, -2], [-9, -1, 5, -3, -3, 8], [-14, 4, -4, 3, -1, 4], [-6, 2, -8, 0, 6, 4], [1, 6, 1, 6, 6, -2], [-7, 5, -9, 2, 2, -5], [1, -6, 1, -2, -4, 2], [-22, 0, -6, 6, 0, 6], [9, -6, -3, 8, 5, -3], [-19, 2, -7, 0, -3, 5], [-9, -1, -3, 2, -2, -5], [1, 2, -9, 0, -8, 1], [13, -4, 7, -2, -10, 3], [-12, -4, -2, -2, -8, 9], [0, -3, 4, 2, 6, -2], [-1, 4, 11, 3, 2, -3], [-16, -8, 2, -1, -6, 4], [-16, -1, -2, -1, 3, -7], [2, 4, -6, 1, -3, 6], [-9, 6, -1, 5, -2, 7], [21, 3, -5, 2, 6, 1], [16, -5, -2, -11, -4, 2], [7, -3, 7, -2, -4, 9], [6, 1, 14, 5, 5, 3], [-2, 0, 8, 0, -6, 6], [9, -4, 1, -4, -8, 0], [13, -9, 3, -10, 0, -3], [-5, 5, 7, 4, -4, 5], [13, 4, 3, 0, 1, 1], [18, -9, 8, -1, 1, 2], [3, 4, 3, -6, 2, -2], [8, -3, -8, 9, 5, -1], [-7, 0, -11, -2, 6, -8], [4, 5, -2, 9, -1, 2], [-16, 6, 4, 7, -1, 2], [18, -1, -4, -5, -1, 0], [5, 1, -5, 7, -3, -2], [0, -1, -14, 5, 6, -2], [-5, -6, 7, -7, 0, 3], [7, 2, 1, 4, 5, -1], [2, 1, -8, 5, 1, -5], [-5, -3, -9, 5, -4, -1], [16, -6, 0, -7, 1, -6], [3, -4, 7, -4, -2, -6], [-2, -6, -2, -2, 4, 0], [-3, -8, 5, 8, 8, 4], [-18, 8, -6, 0, 6, 0], [18, 0, 8, 3, 0, 2], [-13, -7, -11, 4, 8, 5], [-27, 9, -13, -2, 6, -1], [24, -1, -6, -5, -1, -4], [17, 6, -1, 3, 12, -7], [19, 2, -9, 2, 8, -8], [7, 0, 5, 2, -3, 5], [14, 5, 4, -1, 1, -9], [-2, -4, 16, -11, -1, 0], [23, 7, -3, 2, -4, -5], [13, -7, -3, -6, 0, -6], [-23, -8, 9, -4, -5, 9], [3, 5, 3, 0, -2, -10], [10, -8, -2, 4, 0, -1], [24, -5, 6, 3, -2, 2], [14, 0, 2, 5, 1, -8], [19, -8, 7, -2, -8, 4], [5, -10, 1, 3, -2, -1], [5, -4, -7, -6, 2, 0], [2, -3, -8, 7, 7, -6], [-1, -2, -3, -10, -4, -5], [-2, 4, 2, -9, -1, 4], [22, 2, -2, 0, 0, -8], [8, 1, 10, -3, 4, 2], [-2, 1, 8, 9, 1, 1], [-9, -3, 5, 0, -4, 5], [-15, -3, -1, 1, -9, 8], [-6, -3, 4, 7, 1, 0], [18, -4, 16, -1, 5, 2], [17, 1, -15, 12, 8, -7], [2, -5, -6, -4, 0, 6], [8, 1, 2, 1, 2, 0], [-25, 6, 7, 4, -3, 1], [16, 6, 4, 4, 2, 0], [-22, -2, -2, -2, -2, 6], [11, 5, 13, -7, 5, 2], [0, -2, 6, 4, 6, -8], [4, -13, 6, -7, -7, 4], [13, -11, -1, 7, 3, -8], [-17, 4, 3, -6, -1, 1], [-14, 2, 10, 8, 4, 2], [15, 0, -9, 2, 2, -2], [9, -4, 3, 4, 3, -9], [-15, 3, -5, 13, 1, 6], [-6, 5, -8, 11, 9, -5], [7, -2, 1, 1, -7, 8], [11, 7, 13, -1, -3, 8], [15, -2, 3, -9, -1, -8], [3, -4, 11, -1, 2, 7], [-12, 2, 4, 14, 4, -6], [7, 2, -17, 7, 5, -3], [31, -4, 9, -3, 4, 5], [7, 3, 1, 3, -9, 4], [28, 2, -4, 2, -6, 5], [-11, 2, -9, -2, -10, 1], [-33, 1, -7, 5, 5, 6], [2, 4, 6, -2, 0, -9], [-7, 6, -5, -4, -3, -5], [0, -7, -2, 1, 7, 5], [-2, 2, 0, -7, 8, -4], [19, 7, 1, -3, -1, -4], [-6, -4, 6, 2, 0, 9], [-15, -1, -7, -11, -14, 1], [0, 1, -8, 11, 3, -5], [26, -2, 6, -10, -6, 0], [-21, 8, 3, 9, 5, 1], [18, -4, 2, -2, -6, 2], [5, -2, 7, -4, -15, 1], [0, -2, 6, -9, -5, -4], [-5, 8, -7, 7, 5, -7], [13, -7, -13, 14, 6, -7], [7, -3, -5, -7, 4, -3], [4, 0, -22, -4, 4, -8], [-17, -5, -5, 5, -4, -1], [38, -3, 10, -9, -1, -5], [-16, 4, -2, 12, 10, -1], [-15, -1, 7, -2, -6, 13], [16, -5, 8, -11, 1, -5], [-1, -3, -7, -9, -3, -4], [1, -4, -11, 1, 7, -6], [0, -7, 6, 3, -11, 2], [-9, 0, 1, 3, 11, 0], [1, 5, -1, -1, 5, -6], [-14, -8, 2, -6, 4, -4], [8, -12, 0, -8, 2, -2], [-7, 2, 19, -2, -16, 5], [12, -9, 8, 4, 2, 6], [-20, 2, 0, -9, -3, 8], [-9, -9, -3, -2, 4, -7], [1, 4, 5, 8, -1, 9], [6, -1, -8, -1, 9, 4], [-32, -2, 2, -8, -12, 7], [31, -2, -13, 2, 5, -3], [-4, -1, -8, 4, 2, -4], [41, 3, -1, 3, -1, 6], [-19, 13, -5, 3, -1, -2], [7, 5, -3, 12, 4, -5], [-64, 1, -2, 1, -2, 0], [-3, -4, 11, -7, -1, 9], [30, -2, -4, -3, 0, -8], [0, 4, -8, 14, 14, 2], [21, 2, -11, -9, -4, -7], [-1, 6, 3, 0, -9, -11], [-13, 10, 9, 1, 8, -3], [12, 13, 6, -3, 8, -2], [5, -1, 19, 5, -11, 12], [-22, -3, 20, 3, -9, 17], [3, 7, -7, 10, 2, 9], [-12, -5, -2, 1, -4, -8], [7, 4, -3, 6, -1, 7], [-7, 0, 13, 0, 8, -2], [11, 1, -7, 7, 1, 2], [-2, -4, 10, 4, 0, 10], [15, 1, 3, -14, -6, -3], [-16, 4, 8, -1, 5, 0], [-12, -2, 8, -12, -10, -4], [-3, 1, -1, -1, -3, -16], [-16, 0, -2, -9, 3, 4], [5, 1, 9, -7, 0, -3], [-6, 0, -12, 12, 6, 0], [-8, 6, 0, 8, 0, 4], [27, -3, 9, 6, -8, -1], [-7, 9, 3, 8, 10, -13], [5, 0, 9, 3, -8, -1], [-38, 4, -2, 8, -4, -4], [24, -6, -18, -10, 4, -2], [4, 4, -6, -2, 16, -10], [-1, 4, 9, 6, -6, -3], [18, 0, 2, -14, -14, -2], [23, 10, 3, 3, 10, 3], [5, -12, -7, 4, 10, 2], [-2, 10, -8, 0, 0, 4], [-42, 2, 0, 17, 5, 4], [-19, 1, 11, 3, -5, 10], [-8, -8, -2, 6, 8, -1], [11, -7, 1, -17, -7, -10], [-10, 2, 12, 9, -8, 12], [-2, -5, 0, 9, 4, -16], [-8, 6, 14, -7, -11, 10], [-17, 18, 3, 8, 4, 2], [32, 2, -8, 6, 14, 8], [-17, -4, 7, -6, -2, -6], [14, 2, 2, -4, 12, 2], [-30, 0, -4, 8, 4, -2], [16, 6, 10, -7, 1, -4], [16, 6, 12, 2, -10, 8], [-17, 8, 19, -6, -10, 8], [-21, 0, 9, 3, -4, -5], [30, -12, 6, -15, -3, 12], [13, -11, 7, -9, 1, -12], [4, 5, 10, -1, -2, 6], [-21, -6, 7, -16, -15, -5], [-2, -2, 16, 10, 4, 1], [-10, 11, -6, -1, -3, -3], [7, -5, 9, -12, -2, 7], [11, -9, 25, 2, 2, 12], [7, -16, 7, -13, 2, -7], [-26, -2, -12, 5, 8, -4], [-7, -8, 21, -17, -1, 12], [-26, 7, 4, -1, 1, 2], [5, -2, -13, 2, 8, -3], [-30, -8, -8, -4, -8, -6], [20, 10, 10, -7, 11, -4], [-15, 4, -7, 4, 8, 0], [-5, 5, -17, -9, 12, -5], [7, -4, 5, 14, 2, -3], [-14, 7, 4, 7, -5, 3], [25, 10, -7, -10, -6, -10], [30, 3, 2, 9, 15, -1], [-51, -7, 3, -5, -11, 2], [15, -10, 3, 11, 10, -1], [-29, 5, 9, 13, 7, -4], [16, 4, 8, 3, 7, 4], [-55, -11, -3, 5, 0, 3], [27, 2, -17, 5, 5, -16], [16, -11, -10, 5, 8, -12], [1, 6, -7, -2, 2, 2], [-1, -2, 3, 7, 8, -5], [4, -4, 18, 0, -10, 6], [30, -12, -6, 2, 6, -12], [9, 2, 3, -4, 4, -7], [7, 5, 1, -6, 16, -9], [-14, 1, 4, 23, 1, 3], [-32, -1, -6, 3, -5, -8], [-6, 0, 18, -12, -12, 0], [23, 2, 5, -8, -6, 11], [-8, 2, 26, -6, -14, 1], [-13, -6, 15, -16, 0, 6], [7, -18, 13, -7, -13, 13], [27, 7, 9, 2, 0, 17], [-12, 0, -12, 3, 3, -6], [18, 1, -8, -1, -9, 10], [28, -2, -6, -3, -5, 10], [-38, 10, -8, -1, -1, 10], [-11, -4, 21, -2, -14, 14], [-20, 7, 2, -1, -7, 6], [-3, 6, 7, -4, 2, 5], [30, 0, 2, 2, 0, 3], [-17, 6, -9, 16, 4, 8], [-14, -16, 0, -5, -3, -6], [-27, -11, 3, 1, 1, 12], [-31, 0, -7, 6, 8, -6], [3, -4, -9, 8, 0, -6], [-4, 14, -18, 5, 10, -16], [-2, 8, 4, -2, -4, 8], [2, 6, -4, 4, 2, -17], [17, 3, 3, -4, 14, -11], [-25, -4, -5, -6, 8, 8], [8, 20, -8, 9, 15, -6], [-26, 0, -6, 12, 10, -10], [-49, -5, 1, -5, -1, -4], [60, 5, 0, -1, 7, -17], [-9, 4, 5, -12, -5, 9], [-19, -7, 15, -4, 6, 3], [-24, 4, -14, 2, 8, -4], [5, -12, 1, -4, 4, -14], [-16, -4, -4, 9, 15, -16], [17, 16, 1, 1, -2, 3], [16, 0, -8, -2, -2, -2], [-37, 4, 15, 8, -2, 2], [-3, -4, -1, 4, 15, -7], [17, 3, -29, 7, -1, -4], [18, 11, -10, 5, -11, -5], [-32, 5, -18, 7, 5, -2], [11, 0, 5, 0, -4, -9], [-9, -4, 1, 10, 0, 13], [-20, -10, -8, -3, -19, 2], [-4, 9, -6, 11, 5, 10], [34, 3, -2, -1, -3, 15], [32, 7, 2, 3, 17, -12], [15, -8, -3, -2, 5, -1], [-13, -16, -3, 2, 6, 3], [-13, -6, -17, 7, 10, 9], [3, -6, -1, -16, -9, 3], [18, 14, 12, -1, 7, -4], [35, -5, -9, -6, 2, 5], [4, -2, -20, 10, -2, 3], [21, 12, -11, -4, 4, -12], [-28, 2, -6, -3, -2, 6], [23, -6, 1, -24, -4, -7], [14, 14, 14, 0, 2, 9], [16, -2, 2, -12, -12, 5], [34, 3, 0, 11, 12, -8], [-13, 5, -11, -2, -4, 2], [-35, 9, -7, 11, -4, -9], [32, -5, 10, 9, -5, 2], [-5, -6, -5, -12, 6, 4], [-13, -2, 7, 16, -8, 6], [23, 15, 3, -1, 0, -9], [12, -6, 4, 8, 2, -10], [-8, 3, 22, -7, -8, 2], [-9, 2, -9, 7, -5, 0], [20, -5, -14, -7, -17, 10], [8, 1, 2, 3, 3, 20], [8, -3, -26, 3, 2, -4], [25, -2, -19, -1, 4, -11], [1, 2, -31, 0, 15, -15], [13, -4, -31, 5, 16, -11], [-26, -6, 18, -10, -16, 16], [4, 8, 0, 8, -2, -6], [-3, -4, -23, 8, 10, -6], [13, 8, -3, 10, 8, -26], [-1, 2, -13, 11, 16, -11], [27, -10, 21, -17, -3, -11], [17, -4, -1, -15, -5, 10], [-12, 7, -8, -11, 11, -5]];
    aps := ConvertToHeckeField(raw_aps);
    chi := MakeCharacter_2300_a_Hecke(Universe(aps));
    return ExtendMultiplicatively(weight, aps, chi);
end function;


// To make the newform (type ModFrm), type "MakeNewformModFrm_2300_2_a_o();".
// This may take a long time!  To see verbose output, uncomment the SetVerbose lines below.
// The precision argument determines an initial guess on how many Fourier coefficients to use.
// This guess is increased enough to uniquely determine the newform.
function MakeNewformModFrm_2300_2_a_o(:prec:=6)
    chi := MakeCharacter_2300_a();
    f_vec := qexpCoeffs();
    Kf := Universe(f_vec);
    // SetVerbose("ModularForms", true);
    // SetVerbose("ModularSymbols", true);
    S := CuspidalSubspace(ModularForms(chi, 2));
    S := BaseChange(S, Kf);
    maxprec := NextPrime(2999) - 1;
    while true do
        trunc_vec := Vector(Kf, [0] cat [f_vec[i]: i in [1..prec]]);
        B := Basis(S, prec + 1);
        S_basismat := Matrix([AbsEltseq(g): g in B]);
        if Rank(S_basismat) eq Min(NumberOfRows(S_basismat), NumberOfColumns(S_basismat)) then
            S_basismat := ChangeRing(S_basismat,Kf);
            f_lincom := Solution(S_basismat,trunc_vec);
            f := &+[f_lincom[i]*Basis(S)[i] : i in [1..#Basis(S)]];
            return f;
        end if;
        error if prec eq maxprec, "Unable to distinguish newform within newspace";
        prec := Min(Ceiling(1.25 * prec), maxprec);
    end while;
end function;


// To make the Hecke irreducible modular symbols subspace (type ModSym)
// containing the newform, type "MakeNewformModSym_2300_2_a_o();".
// This may take a long time!  To see verbose output, uncomment the SetVerbose line below.
// The default sign is -1.  You can change this with the optional parameter "sign".
function MakeNewformModSym_2300_2_a_o( : sign := -1)
    R<x> := PolynomialRing(Rationals());
    chi := MakeCharacter_2300_a();
    // SetVerbose("ModularSymbols", true);
    Snew := NewSubspace(CuspidalSubspace(ModularSymbols(chi,2,sign)));
    Vf := Kernel([<3,R![-16, -38, 5, 30, -6, -4, 1]>,<7,R![288, -228, -152, 88, 10, -9, 1]>],Snew);
    return Vf;
end function;