On Wed, May 28, 2003 at 10:07:39PM -0400, Dale Lancaster wrote:
> For the perl hash, I would key the hash on the combo of planet and date,
> something like:
>
> my %Planets = (
>
> jupiter => {
> "1900-01-01" => ( "5h 39m 18s", "+22o
> 4.0'", 28.922, -15,128, -164.799, "set"),
> "1900-01-02" => ( "5h 39m 18s", "+22o
> 4.0'", 28.922, -15,128, -164.799, "set"),
> },
>
> neptune => {
> "1900-01-01" => ( "5h 39m 18s", "+22o
> 4.0'", 28.922, -15,128, -164.799, "set"),
> "1900-01-02" => ( "5h 39m 18s", "+22o
> 4.0'", 28.922, -15,128, -164.799, "set"),
> },
> ) ;
my $Planets = {
jupiter => {
1900 => {
01 => {
01 => 1, # Record number in a file
02 => 2,
}.
02 => { ...},
....
This would not require the entire dataset to be stored in memory but rather an offset
to a file possition which could be randomly accessed.
However If I ever heard of a case for use of a fixed width ascii file using spacing
records this is it.
If you had one file per planet and assuming that you wanted to start on 1900-01-01
my $record_width=90;
my $offset = (($year-1900)*372+(($month-1)*31)+($day-1))*$record_width;
# 1900-01-01 would be offset 0
# 2003-06-13 would be offset 3463560
This format would require blank records inserted for 1900-02-30 etc. but a simple
script could auto generate the file.
One advantage of this would be the OS would file cache the read only file.
Just my toughts, hope it helps.
Paddy
