in reply to Re: [OT] Mysterious function.
in thread [OT] Mysterious function. (Updated)

Thanks. You inspired a way to work out the transition points:

#! perl -slw
use strict;


sub func {
    my $vv = shift;

    my $bb = 140*24*60*60*1000; ##140 days
    if( $vv >= $bb ) { ##140 days < 5 months
        $bb = 8766*60*60*1000;##1 year
        if( $vv < $bb         ) { return( $bb/12 );  } ## 1 year      
+ ##1 month
        if( $vv < $bb *2      ) { return( $bb/6 );   } ## 2 years     
+ ##2 month
        if( $vv < $bb *5/2    ) { return( $bb/4 );   } ## 2.5 years   
+ ##3 month
        if( $vv < $bb *5      ) { return( $bb/2 );   } ## 5 years     
+ ##6 month
        if( $vv < $bb *10     ) { return( $bb );     } ## 10 years    
+ ##1 year
        if( $vv < $bb *20     ) { return( $bb*2 );   } ## 20 years    
+ ##2 years
        if( $vv < $bb *50     ) { return( $bb*5 );   } ## 50 years    
+ ##5 years
        if( $vv < $bb *100    ) { return( $bb*10 );  } ## 100 years   
+ ##10 years
        if( $vv < $bb *200    ) { return( $bb*20 );  } ## 200 years   
+ ##20 years
        if( $vv < $bb *500    ) { return( $bb*50 );  } ## 500 years   
+ ##50 years
        return( $bb*100 );                       ##100 years
    }
    $bb /= 2; ##70 days
    if( $vv >= $bb ) { return( $bb/5 ); } ##14 days
    $bb /= 2; ##35 days
    if( $vv >= $bb ) { return( $bb/5 ); } ##7 days
    $bb /= 7; $bb *= 4; ##20 days
    if( $vv >= $bb ) { return( $bb/5 ); } ##4 days
    $bb /= 2; ##10 days
    if( $vv >= $bb ) { return( $bb/5 ); } ##2 days
    $bb /= 2; ##5 days
    if( $vv >= $bb ) { return( $bb/5 ); } ##1 day
    $bb /= 2; ##2.5 days
    if( $vv >= $bb ) { return( $bb/5 ); } ##12 hours
    $bb *= 3; $bb /= 5; ##1.5 day
    if( $vv >= $bb ) { return( $bb/6 ); } ##6 hours
    $bb /= 2; ##18 hours
    if( $vv >= $bb ) { return( $bb/6 ); } ##3 hours
    $bb *= 2; $bb /= 3; ##12 hours
    if( $vv >= $bb ) { return( $bb/6 ); } ##2 hours
    $bb /= 2; ##6 hours
    if( $vv >= $bb ) { return( $bb/6 ); } ##1 hour
    $bb /= 2; ##3 hours
    if( $vv >= $bb ) { return( $bb/6 ); } ##30 mins
    $bb /= 2; ##1.5 hours
    if( $vv >= $bb ) { return( $bb/6 ); } ##15 mins
    $bb *= 2; $bb /= 3; ##1 hour
    if( $vv >= $bb ) { return( $bb/6 ); } ##10 mins
    $bb /= 3; ##20 mins
    if( $vv >= $bb ) { return( $bb/4 ); } ##5 mins
    $bb /= 2; ##10 mins
    if( $vv >= $bb ) { return( $bb/5 ); } ##2 mins
    $bb /= 2; ##5 mins
    if( $vv >= $bb ) { return( $bb/5 ); } ##1 min
    $bb *= 3; $bb /= 2; ##3 mins
    if( $vv >= $bb ) { return( $bb/6 ); } ##30 secs
    $bb /= 2; ##1.5 mins
    if( $vv >= $bb ) { return( $bb/6 ); } ##15 secs
    $bb *= 2; $bb /= 3; ##1 min
    if( $vv >= $bb ) { return( $bb/6 ); } ##10 secs
    $bb /= 3; ##20 secs
    if( $vv >= $bb ) { return( $bb/4 ); } ##5 secs
    $bb /= 2; ##10 secs
    if( $vv >= $bb ) { return( $bb/5 ); } ##2 secs
    return( $bb/10 ); ##1 sec
}

my $last = 0;
my $step = 2500;
for( my $i = 1; $i < 100*365.25*24*60*60*1000; $i += $step ) {
    my $new = func( $i );
    if( $new > $last ) {
        printf "%20u -> %20u\n", $i, $new;
        $step = ( $new - $last ) / 10;
        $last = $new;
    }
}

__END__
[19:49:46.77] E:\Chart>junk
                   1 ->                 2500
               25001 ->                 5000
               50001 ->                12500
              150501 ->                25000
              225501 ->                37500
              300501 ->                60000
              602001 ->               120000
             1202001 ->               300000
             3614001 ->               600000
             5414001 ->               900000
            10814001 ->              1800000
            21614001 ->              3600000
            43214001 ->              7200000
            64814001 ->             10800000
           129614001 ->             21600000
           216014001 ->             43200000
           432014001 ->             86400000
           864014001 ->            172800000
          1728014001 ->            345600000
          3024014001 ->            604800000
          6056654001 ->           1209600000
         12104654001 ->           2629800000
         31561394001 ->           5259600000
         63118994001 ->           7889400000
         78897794001 ->          15778800000
        157791794001 ->          31557600000
        315579794001 ->          63115200000
        631155794001 ->         157788000000
       1577883794001 ->         315576000000

[download]
I used node.js to produce some interesting edge cases.

'scuse my ignorance, but does node.js allow you to run JS at the command line?

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.
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Re^3: [OT] Mysterious function.
by jeffa (Bishop) on Apr 23, 2015 at 19:29 UTC

    Excellent! :) Yes, node.js allows you to run JS at the command line. It is quite a handy tool to have at your disposal: 

    var last = 0
var step = 2500
for (var i = 1; i <= 100*365.25*24*60*60*1000; i += step) {
    j = _DateInterval( i )
    if ( j > last ) {
        console.log( i + ' -> ' + j );
        step = ( j - last ) / 10;
        last = j;
    }
}

function _DateInterval( vv ) {

 ....
}

    [download]

    jeffa

    L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)
[reply]
[d/l]

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