Prof. J. E. Cremona on Thu, 30 Sep 2004 11:01:01 +0200 |
[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]
sorting problems |
trivial example: 3<12 but "12"<"3" : (09:32) gp > a=[12,3] %122 = [12, 3] (09:40) gp > ia=vecsort(a,,1) %123 = [2, 1] (09:40) gp > sa=vecextract(a,ia) %125 = [3, 12] (09:41) gp > setsearch(sa,12) %126 = 0 (09:41) gp > setsearch(Set(sa),12) %127 = 1 (09:41) gp > Set(sa) %128 = ["12", "3"] (09:41) gp > setsearch(Set(sa),3) %130 = 2All I need in the end is: given a (large) vector [x_1,x_2,...,x_n] of (unsorted) integers, I want to be able to ask of any integer x if x=x_i for some i and of so which....surely a common task!
John -- Prof. J. E. Cremona | University of Nottingham | Tel.: +44-115-9514920 School of Mathematical Sciences | Fax: +44-115-9514951 University Park | Email: John.Cremona@nottingham.ac.uk Nottingham NG7 2RD, UK | This message has been scanned but we cannot guarantee that it and any attachments are free from viruses or other damaging content: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation.