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Geo::WeatherNOAA.3pm

NAME

Geo::WeatherNOAA - Perl extension for interpreting the NOAA weather data

SYNOPSIS

   use Geo::WeatherNOAA;
   ($date,$warnings,$forecast,$coverage) = 
      process_city_zone('newport','ri','','get');
 
 

   foreach $key (keys %$forecast) {
         print "$key: $forecast->{$key}\n";
   }
 
 

   print process_city_hourly('newport news', 'va', '', 'get');
 
 

or

   use Geo::WeatherNOAA;
   print print_forecast('newport news','va');
 
 

DESCRIPTION

This module is intended to interpret the NOAA zone forecasts and current city hourly data files. It should give a programmer an easy time to use the data instead of having to mine it.

Be aware that if the variable $main::opt_v is set to anything (other than zero or '') then Geo::WeatherNOAA will be verbose on what it's doing with messages sent to STDERR. Useful for debugging.

REQUIRES

* Tie::IxHash

* LWP::Simple

* LWP::UserAgent

* Text::Wrap

FUNCTIONS

* print_forecast(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent)

Returns text of the forecast

* print_current(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent)

Returns text of current weather

* make_noaa_table(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent, MaxItems)

This call gives the basic html table with current data and forecast for the next four periods (``tonight'', ``tomorrow'',``tomorrow night'',``day after'') and warnings in an (I think) attractive, easy to read way.

Max Items is a way to limit the number of items in the table returned... I think it looks best with no more than 4...5 gets crowded looking.

* process_city_hourly(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent)

FILENAME is the file read from with FILEOPT ``usefile'' and written to if FILEOPT is ``save''

FILEOPT can be one of the following

         - save
                 will get and save the data to FILENAME
         - get
                 will retrieve new data (not store it)
         - usefile
                 will not retrieve data from URL, 
                 use FILENAME for data
 
 

The fifth argument is for a user created LWP::UserAgent(3) which can be configured to work with firewalls. See the LWP::UserAgent(3) manpage for specific instructions. A basic example is like this:

    my $ua = new LWP::UserAgent;
    $ua->proxy(['http', 'ftp'], 'http://proxy.my.net:8080/');
 
 

NOTE: You may also set the environment variable <CODE>http_proxy</CODE> and the auto-generated LWP::UserAgent will use LWP::UserAgent::env_proxy(). See LWP::UserAgent for more details.

* process_city_zone(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent)

Call CITY, STATE, FILENAME (explained above), FILEOPT(explained above), and UserAgent (Explained above).

The return is a three element list containing a) a string of the date/time of the forecast, b) a reference to the list of warnings (if any), and c) a reference to the hash of forecast. I recommend calling it like this:

     ($date, $warnings, $forecast, $coverage) = 
         process_city_zone('newport news','va',
         '/tmp/va_zone.html', 'save');
 
 

Explanation of this call, it returns:

         $date
         - Scalar of the date of the forecast
 
 

         $warnings
         - Reference to the warnings list
         - EXAMPLE:
           foreach (@$warnings) { print; }
 
 

         $forecast
         - Reference to the forecast KEY, VALUE pairs
         - EXAMPLE:
           foreach $key (keys %$forecast) {
                 print "$key: $forecast->{$key}\n";
           }
 
 

         $coverage
         - Scalar of the coverage area of the forecast
 
 

* get_city_zone(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent)

This sub is to get the block of data from the data source, which is chosen with the FILEOPTswitch.

* get_city_hourly(CITY,STATE,FILENAME,FILEOPT,LWP_UserAgent)

This function gets the current weather from the data source, which is decided from FILEOPT(explained above). Input is CITY, STATE, FILENAME (filename to read/write from if FILEOPTis ``get'' or ``usefile''), and UserAgent.

This function returns a reference to a hash containing the data. It

Same FILEOPTand LWP_UserAgent from above, and process the current weather data into an english sentence.

AUTHOR

Mark Solomon

msolomon@seva.net

http://www.seva.net/~msolomon/

SEE ALSO

perl(1), Tie::IxHash(3), LWP::Simple(3), LWP::UserAgent(3).