20211229, 19:25  #12  
"James Heinrich"
May 2004
exNorthern Ontario
4071_{10} Posts 
Quote:
There is a separate database table that records the PRP/prime "last factor" for fullyfactored numbers which is where most (all?) of the instances of >1024bit numbers are stored (and read from). If someone knows a better way to calculate log2 for such numbers (either in PHP or possibly some CLI call to an external program) please let me know. In this case I can most likely go through the 134 affected exponents and properly calculate the lastfactor bitsize from the size of all the other factors. I'll post back when I have done so. edit: the exponents that were off (by more than .01 bits) Code:
M 1,723: should be 1,326.34065 not 1,328.77124 diff: 2.43058 M 1,999: should be 1,418.58406 not 1,421.78522 diff: 3.20117 M 2,029: should be 1,591.37478 not 1,594.52549 diff: 3.15070 M 2,351: should be 1,988.78693 not 1,989.83493 diff: 1.04800 M 2,357: should be 2,151.62368 not 2,152.60941 diff: 0.98573 M 2,441: should be 2,158.51624 not 2,159.25326 diff: 0.73702 M 2,749: should be 2,329.88124 not 2,331.99352 diff: 2.11228 M 2,789: should be 2,334.28500 not 2,335.31545 diff: 1.03045 M 2,887: should be 2,656.76445 not 2,657.54248 diff: 0.77802 M 3,089: should be 2,798.74096 not 2,800.38538 diff: 1.64443 M 3,037: should be 2,841.56270 not 2,843.57045 diff: 2.00775 M 3,203: should be 2,958.40816 not 2,959.83793 diff: 1.42977 M 3,307: should be 2,971.92590 not 2,973.12564 diff: 1.19974 M 3,467: should be 3,150.24549 not 3,152.50976 diff: 2.26428 M 3,413: should be 3,157.52277 not 3,159.15362 diff: 1.63085 M 3,733: should be 3,263.20825 not 3,265.45532 diff: 2.24706 M 3,637: should be 3,320.98003 not 3,321.92809 diff: 0.94806 M 4,021: should be 3,525.91920 not 3,527.88764 diff: 1.96843 M 3,917: should be 3,624.14333 not 3,624.22355 diff: 0.08022 M 4,111: should be 3,928.18026 not 3,929.84094 diff: 1.66068 M 4,349: should be 3,948.44975 not 3,949.77250 diff: 1.32275 M 4,507: should be 4,309.23022 not 4,311.86267 diff: 2.63245 M 5,393: should be 5,010.08307 not 5,012.78950 diff: 2.70643 M 7,013: should be 6,486.79244 not 6,487.72557 diff: 0.93313 M 6,679: should be 6,501.25682 not 6,504.33521 diff: 3.07839 M 7,669: should be 7,450.80075 not 7,451.08472 diff: 0.28397 M 8,233: should be 7,951.92887 not 7,952.69586 diff: 0.76699 M15,359: should be 15,146.96351 not 15,147.99211 diff: 1.02861 M22,193: should be 21,995.55279 not 21,997.80784 diff: 2.25506 M32,611: should be 32,341.32470 not 32,342.29193 diff: 0.96724 M51,487: should be 51,337.52372 not 51,340.39871 diff: 2.87499 M82,939: should be 82,839.52114 not 82,842.24283 diff: 2.72169 M84,211: should be 84,014.52029 not 84,014.88345 diff: 0.36315 Last fiddled with by James Heinrich on 20211229 at 19:42 

20211229, 19:51  #13 
"James Heinrich"
May 2004
exNorthern Ontario
3·23·59 Posts 
I have corrected the 33 affected exponents, and updated the bit of code where these slightlyoff bitsize values for PRP cofactors is entering the database to automatically look up the correct bitsize value when a new large value is entered.
Thanks for letting me know. 
20211229, 20:42  #14  
"Robert Gerbicz"
Oct 2005
Hungary
3^{2}·179 Posts 
Quote:
Code:
double getlog2(string s){ int L=s.length(); if(L<=16) return log(stoll(s))/log(2); return (log(stoll(s.substr(0,16)))+(double)(L16)*log(10))/log(2); } Make sure that in your language it is working also on the 1016 string length, otherwise maybe write everywhere 9 instead of 16 [you'll get slightly larger error in the log2 computation].. Last fiddled with by R. Gerbicz on 20211229 at 20:44 Reason: typo 

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