Syntactic Confectionery Delight PerlMonks

### Comment on

 Need Help??

Your code is full of silly inefficiencies; like these 3 calculations:

```\$data->{magX}[ \$dataIdx ] * cos( \$data->{phX}[ \$dataIdx ] )
\$data->{magY}[ \$dataIdx ] * cos( \$data->{phY}[ \$dataIdx ] )
\$data->{magZ}[ \$dataIdx ] * cos( \$data->{phZ}[ \$dataIdx ] )

being performed for all 50 million \$data points; and all 50 million being repeated for every one of the "thousands" of \$center points. That's 3 * "thousands" * "50.000.000" of redundant, repeated calculations.

Also, whilst I won't pretend to fully understand your code in isolation of what TransfNorVec(), coordSystTransf() & Check() subs do, it seems fairly clear you are checking a bunch of 3D points against another bunch of 3D points and accumulating statistics about how many of the former are within some distance of some of the latter.

And you are going about it by brute force.

With a clearer picture of the data (in \$data (what an awful name) and \$center), it ought to be possible to order (sort or structure -- perhaps 3-dimensionally) them, so that for any given \$input only a small subset of the 'thousands by millions' of comparisons (and associated calculations) need be done.

For example, if the point's X value is 50 and the radius of the compare is 5, there is no point in comparing against any other point who's X-value is outside of 45 thru 55. Sub-setting the larger range early could save billions of calculations, comparisons, object constructions and function calls.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

• Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
• Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
• Read Where should I post X? if you're not absolutely sure you're posting in the right place.
• Please read these before you post! —
• Posts may use any of the Perl Monks Approved HTML tags:
a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
• You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
 For: Use: & & < < > > [ [ ] ]
• Link using PerlMonks shortcuts! What shortcuts can I use for linking?
• See Writeup Formatting Tips and other pages linked from there for more info.

Create A New User
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others cooling their heels in the Monastery: (6)
As of 2018-11-15 08:29 GMT
Sections?
Information?
Find Nodes?
Leftovers?
Voting Booth?
My code is most likely broken because:

Results (182 votes). Check out past polls.

Notices?