Jacques Gélinas on Wed, 21 Mar 2018 11:58:18 +0100 |
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Derivatives of the Riemann xi function at s=1/2 |
Rick Kreminski computed in 2003 and 2005 highly accurate values of the Stieltjes constants for (s-1)zeta(s), and from them the even derivatives of xi(s), available in http://faculty.csupueblo.edu/rick.kreminski/stieltjesrelated/xiderest.txt His Mathematica data files contain an embedded precision estimate, such as xiderest[490] = 1.98904329578698357865221553147716608602180248569469934098308\ 688689767666203002349477596872`77.6054*^80 and can be converted to a format accepted by Pari/GP with the following sed script (see the appended text file for comments). # xiderest.sed: Convert a Mathematica data file to PARI/GP format # Usage: sed --text -f xiderest.sed xiderest > xiderest.gp /`.*\\$/h; /`.*\\$/d; /`\|\\$/!H; /`\|\\$/!x; s/\\\n//; s/`\(.*\)\*^\(.*\)/E\2`\1/; s/`/; \\\\/; # End of file xiderest.sed These values can be verified with the double-exponential integration of Pari/GP, giving for example the derivative of order 20,000 with 2100 digits on a laptop computer. Are there other numerical values available ? Jacques Gélinas, Ottawa
#============================================= xiderest.sed # # Convert a data file from Mathematica to PARI/GP # # xiderest[1] = 0 / = 0$/d; # blank lines /^.\?$/d; # 2864824522574683538316274864488477`121\ # .4772*^75 # ==> 2864824522574683538316274864488477`121.4772*^75 # # 2864824522574683538316274864488477`121\ # .069 # ==> 2864824522574683538316274864488477`121.069 /`.*\\$/h; /`.*\\$/d; /`\|\\$/!H; /`\|\\$/!x; s/\\\n//; # 688689767666203002349477596872`77.6054*^80 # ==> 688689767666203002349477596872E80`77.6054 s/`\(.*\)\*^\(.*\)/E\2`\1/; # 14693726641604350416778354683116048`800 # ==> 14693726641604350416778354683116048; \\800 s/`/; \\\\/; #============================================= end-of-file