COMMAND LINE OPTIONS FOR MWRANK Since December 1997, mwrank supports command-line options instead of prompting the user. All options have reasonable defaults. List of command line options, their meaning and default values [q, l, t take no parameters; the others take an integer parameter "n"] -h help Displays a summary of this info and quits -q quiet mode flag Suppresses the header information (including the date of compilation) which is otherwise output and should be included in any problem/bug reports). Default is off (i.e. not quiet). Also suppresses prompting for curves. -v n verbosity level Controls amount of output. Range 0..3. Default=1. Level 0 only outputs the rank. Use "-q -v 0" for minimal output, but note that if you also have "-c n" with nonzero n then you will cause a point search to be carried out, but you will not see its results! (Unless -o is used). Details of point search only shown if verbosity is > 1. -o output pari Outputs a very terse summary of the results for use by PARI/GP with suitable interface. Format: Either [[r],[P1,P2,...,Pr]] where r is the rank and P1,...,Pr are r independent points; or [[r,r'],[P1,P2,...,Pr]] where r and r' are lower and upper bounds on the rank and P1,...,Pr are r independent points; Can be used in addition to other output options (controlled by -v); for minimal useful output use "-q -v 0 -o" -p n precision (#dp) Only relevant for the LiDIA multiprecision floating point versions. Range 1..large, default 15. -b n height bound for quartic point search. Range 1..15, default 10. 5 is large enough for many curves. -x n number of auxiliary primes used for syzygy sieving. Range 0..,default 6. Only relevant for curves with no 2-torsion. Only worth increasing either for curves with large discriminant, or for curves with suspected large rank r, for which r+1 is a good value. -l points output flag. Controls whether generating points are output. Defaults to value of "verbosity", so the only function is to turn this part of the output on when verbosity is 0 (i.e. -v 0 -l). -t quartic equivalence test flag. For debugging only. Default off. -s selmer_only If set, does local tests on homogeneous spaces only, which can be much quicker for curves with 2-torsion. NB for curves with no 2-torsion this computes the 2-Selmer rank exactly; for curves with 2-torsion it computes an upper bound for the rank based on various Selmer groups, possibly less than that from the 2-Selmer group itself. If unset (the default) then rational points are sought, to give a lower bound for the rank also. -d skip_2nd_descent Only relevant for curves with 2-torsion; unset by default. If set, does no second descent either locally or globally, which in general gives a larger upper bound for the rank and a smaller lower bound. I recommend setting this if using mwrank with no multiprecision floating point arithmetic. -S saturation_bound (non-negative integer or -1) controls saturation 0: do no saturation at all n: use n as upper bound for saturation primes -1: allow progam to determine upper bound autimatically (but that will be reduced to a default maximum of 100 if it is greater) OBSOLETE option(s) which no longer have any effect: -c n height bound for curve point search. This controls the point search after 2-descent. Range: -1,0,1..15 (default=0) (larger values take a very long time, and probably cause overflow owing to a technical problem which I have not yet fixed, so the program currently uses 15 if you give it any value > 15). If -1, then the program attempts to compute a suitable value which would guarantee that the full MW group was found, but this feature is not at all efficient, can easily lead to bounds >15 and hence problems, so the truncation at 15 is applied if necessary. If 0 (default) then no point search is done. NB If this value is nonzero then you should have a nonzero value for -v and/or the option -o switched on, otherwise the program carries out a point search but you do not see its results, only the rank!