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Old 2021-05-13, 14:31   #56
EdH
 
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"Ed Hall"
Dec 2009
Adirondack Mtns

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Quote:
Originally Posted by garambois View Post
Thanks Edwin for all your hard work !
I have some questions, remarks, answers, information...

1) Would it be possible to show us an example of an entry to achieve an "Advanced Search" ?
Using your previous example:
Code:
[n%2==0, a==0, b, c, d, e==0, f, g, h, i, j, 1.7<k<2.3, l, m]
and translating for the change of elements:
Code:
$ ./seqinfo2 regina_file_1e5 
Data available for sequences 2 through 100000 
Sequence endings - prime: 85544, cycle: 2225, open: 12230 
Enter sequence (##/a/h/p/p##/q/u): a 
Advanced routine 
Sequence filter a (mod b) (a b): 2 
Sequence range (begin end):  
All, Prime, Open, Cylce (a/p/o/c): o 
Range for number of relative minimums (min max):  
Range for number of relative maximums (min max): 0 
Range for number of parity changes (min max):  
Range for number of consecutive even abundant terms (min max):  
Range for number of consecutive even deficient terms (min max):  
Range for number of consecutive odd deficient terms (min max):  
Range for number of consecutive odd abundant terms (min max):  
Range for number of downdriver extracts (min max):  
Range for smallest quotient of two consecutive terms (min max):  
Range for largest quotient of two consecutive terms (min max):  
Range for arith mean of all quotients of 2 consequtive terms (min max): 1.7 2.3 
Range for geo mean of all quotients of 2 consequtive terms (min max):  
Range for arith mean of # of digits of all the mins (min max):  
Range for arith mean of # of digits of all the maxes (min max):  
List filtered sequences for 0 (mod 2) from 2 through 100000? (y/n/c/f): y
. . .
17360     17544     17994     18006     18018     18138     18150     18490
18702     18786     18798     18888     19040     19410     19500     19560
19656     20204     20382     20640     21096     21198     21210     21234
21246     21258     21384     21582     21858     21870     22132     22392     
. . .
842 sequences found. 
 Enter sequence (##/a/h/p/p##/q/u):
Of course, this was only with a regina_file that was limited to 1e5 and I showed only 32 of 842 sequences, to include 19560 which you referenced earlier.

I entered "a" to call up the Advanced Routine. Then "2" for 0 (mod 2), "o" for open sequences, "0" for maximums, which became the range 0-0, and "1.7 2.3" for the arithmetic mean range. In this case I was inclusive of the values, whereas the original wasn't. I suppose "1.700001 2.29999" could have been used.
Quote:
Originally Posted by garambois View Post
2) After less than 3 weeks of computation, the new program came to more than 4,000,000. So I think it should reach 20 M sometime this summer. But then, the RAM needed to run the program should become too large for almost all computers, unless I am wrong ! For sequences up to 20 M, the file will be over 2 GB. And in python, in my experience, it is impossible to process such a file by storing it in RAM : it takes much more memory than the file size. But maybe it's different in C, I hope so !

3) Just for information, I am thinking of letting the program run for several months and this new program could process all the sequences up to 50 M, or even more... if my old computer does not break down.
I've placed a limit of 20M in the code at present, but I have no idea what the memory usage would actually be. Or, what happens when there's not enough RAM. Theoretically, I think it should move into swap space, but then what?
Quote:
Originally Posted by garambois View Post
4)

There can be no other negative value than B in the table, that is for sure.
Great! Thanks.
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