1 COMMAND LINE OPTIONS FOR MWRANK 2 3Since December 1997, mwrank supports command-line options instead of 4prompting the user. All options have reasonable defaults. 5 6List of command line options, their meaning and default values (set in options.h) 7 8[q, l, t take no parameters; the others take an integer parameter "n"] 9 10-h help Displays a summary of this info and quits 11 12-q quiet mode flag 13 Suppresses the header information (including 14 the date of compilation) which is otherwise output 15 and should be included in any problem/bug reports). 16 Default is off (i.e. not quiet). Also 17 suppresses prompting for curves 18 19-v n verbosity level 20 Controls amount of output. Range 0..3. 21 Default=1. Level 0 only outputs the rank. 22 Use "-q -v 0" for minimal output, but note 23 that if you also have "-c n" with nonzero n 24 then you will cause a point search to be 25 carried out, but you will not see its results! 26 (Unless -o is used). 27 Details of point search only shown if 28 verbosity is > 1. 29 30-o output pari Outputs a very terse summary of the results 31 for use by PARI/GP with suitable interface. 32 Format: 33 Either [[r],[P1,P2,...,Pr]] 34 where r is the rank and P1,...,Pr are r 35 independent points; 36 or [[r,r'],[P1,P2,...,Pr]] 37 where r and r' are lower and upper bounds 38 on the rank and P1,...,Pr are r 39 independent points; 40 Can be used in addition to other output 41 options (controlled by -v); for minimal useful 42 output use "-q -v 0 -o" 43 44-p n precision (#bits) 45 Only relevant for the multiprecision 46 floating point version. Range 1..large, 47 default 50. This is bit precision. 48 Stringly recommended to increase for curves 49 with 2-torsion where a second descent is used 50 since then the reduction applied to second 51 descent quartics is more effective. 52 53-b n height bound for quartic point search. 54 Range 1..15, default 10. 55 56-x n number of auxiliary primes used for syzygy sieving. 57 Range 0..,default 15. Only relevant for curves 58 with no 2-torsion. Worth increasing 59 either for curves with large discriminant, or 60 for curves with suspected large rank r, for 61 which r+1 or r+2 are suitable values. 62 63-l points output flag. 64 Controls whether generating points are output. 65 Defaults to value of "verbosity", so the only 66 function is to turn this part of the output on 67 when verbosity is 0 (i.e. -v 0 -l). 68 69-t quartic equivalence test flag. 70 For debugging only. Default off. 71 72-s selmer_only If set, does local tests on homogeneous spaces 73 only, which can be much quicker for curves 74 with 2-torsion. NB for curves with no 75 2-torsion this computes the 2-Selmer rank 76 exactly; for curves with 2-torsion it 77 computes an upper bound for the rank based on 78 various Selmer groups, possibly less than that 79 from the 2-Selmer group itself. 80 If unset (the default) then rational points 81 are sought, to give a lower bound for the rank 82 also. 83 84-d skip_2nd_descent Only relevant for curves with 2-torsion; 85 unset by default. If set, does no second 86 descent either locally or globally, which in 87 general gives a larger upper bound for the 88 rank and a smaller lower bound. 89 I recommend setting this if using mwrank with 90 no multiprecision floating point arithmetic. 91 92-S saturation_bound (non-negative integer or -1) controls saturation 93 0: do no saturation at all 94 n: use n as upper bound for saturation primes 95 -1: allow progam to determine upper bound 96 automatically (but that will be reduced to a 97 default maximum of 100 if it is greater) 98 99Last update: 2016-01-02 100