This directory contains 4 files related to the paper "A database of nonhyperelliptic genus 3 curves over Q" by Andrew V. Sutherland.

tfdisc.m -- Magma code to compute resultants and discriminants of ternary forms as described in Section 2 of the paper.

8233generic.m -- Magma code proving that the Jacobians of the hyperelliptic and nonhyperelliptic curves of discriminant -8233 both have maximal Mumford=Tate groups, as described in Section 6 of the paper.

spqcurves.txt -- list of smooth plane quartics with absolute discriminant < 10^7.  Format of each line is |Disc(f)|:f(x,y,z), sorted by |Disc(f)|.

spqdisc.txt -- discriminant polynomial for ternary quartic forms.  Format of each line is e1,...,e15,c, corresponding to the term a1^e1*...*a15^e15*c, where the variables a1,...,a15 are the coefficients of a generic ternary quartic form a1*x^4 + a2*x^3*y + ... + a14*y*z^3 + a15*z^4 with monomials in x,y,z ordered lexicographically.  For example, the last line of the file 9,0,0,0,0,0,0,0,0,0,9,0,0,0,9,-1099511627776 gives the discriminant -2^40*a1^9*a11^9*a15^9 of the terneary quartic form a1*x^4 + a11*y^4 + a15*z^4.