which was adapted from a BASIC program from the Astronomical Computing column of Sky & Telescope, April 1994
*/
function isdayofmonth($month, $day, $year)
{
$dim = array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
if ($month != 2)
{
if (1 <= $day && $day <= $dim[$month - 1])
return true;
else
return false;
}
$feb = $dim[1];
if (isleapyear($year))
{
$feb++;// is leap year
}
if (1 <= $day && $day <= $feb)
{
return true;
}
return false;
}
function isleapyear($year)
{
$a = floor($year - 4 * floor($year / 4));
$b = floor($year - 100 * floor($year / 100));
$c = floor($year - 400 * floor($year / 400));
// possible leap year
if ($a == 0)
{
if ($b == 0 && $c != 0)
return false;// not leap year
else
return true;// is leap year
}
return false;
}
// compute moon position and phase
function moon_posit($month = null, $day = null, $year = null)
{
$moon = array();
if(!isdayofmonth($month, $day, $year))
{
$moon['errors'] = 'Invalid date';
}
else
{
$moon['errors'] = null;
$age = 0.0;// Moon's age in days from New Moon
$distance = 0.0;// Moon's distance in Earth radii
$latitude = 0.0;// Moon's ecliptic latitude in degrees
$longitude = 0.0;// Moon's ecliptic longitude in degrees
$phase = '';
$zodiac = '';
$YY = 0;
$MM = 0;
$K1 = 0;
$K2 = 0;
$K3 = 0;
$JD = 0;
$IP = 0.0;
$DP = 0.0;
$NP = 0.0;
$RP = 0.0;
// calculate the Julian date at 12h UT
$YY = $year - floor((12 - $month) / 10);
$MM = $month + 9;
if ($MM >= 12)
{
$MM = $MM - 12;
}
$K1 = floor(365.25 * ($YY + 4712));
$K2 = floor(30.6 * $MM + 0.5);
$K3 = floor(floor(($YY / 100) + 49) * 0.75) - 38;
$JD = $K1 + $K2 + $day + 59;// for dates in Julian calendar
if ($JD > 2299160)
{
$JD = $JD - $K3;// for Gregorian calendar
}
// calculate moon's age in days
$IP = normalize(($JD - 2451550.1) / 29.530588853);
$age = $IP * 29.53;
if ($age < 1.84566)
$phase = 'NEW';
else if ($age < 5.53699)
$phase = 'Evening crescent';
else if ($age < 9.22831)
$phase = 'First quarter';
else if ($age < 12.91963)
$phase = 'Waxing gibbous';
else if ($age < 16.61096)
$phase = 'FULL';
else if ($age < 20.30228)
$phase = 'Waning gibbous';
else if ($age < 23.99361)
$phase = 'Last quarter';
else if ($age < 27.68493)
$phase = 'Morning crescent';
else
$phase = 'NEW';
$IP = $IP * 2 * pi();// Convert phase to radians
// calculate moon's distance
$DP = 2 * pi() * normalize(($JD - 2451562.2) / 27.55454988);
$distance = 60.4 - 3.3 * cos($DP) - 0.6 * cos(2 * $IP - $DP) - 0.5 * cos(2 * $IP);
// calculate moon's ecliptic latitude
$NP = 2 * pi() * normalize(($JD - 2451565.2) / 27.212220817);
$latitude = 5.1 * sin($NP);
// calculate moon's ecliptic longitude
$RP = normalize(($JD - 2451555.8) / 27.321582241);
$longitude = 360 * $RP + 6.3 * sin($DP) + 1.3 * sin(2 * $IP - $DP) + 0.7 * sin(2 * $IP);
if ($longitude < 33.18)
$zodiac = 'Pisces';
else if ($longitude < 51.16)
$zodiac = 'Aries';
else if ($longitude < 93.44)
$zodiac = 'Taurus';
else if ($longitude < 119.48)
$zodiac = 'Gemini';
else if ($longitude < 135.30)
$zodiac = 'Cancer';
else if ($longitude < 173.34)
$zodiac = 'Leo';
else if ($longitude < 224.17)
$zodiac = 'Virgo';
else if ($longitude < 242.57)
$zodiac = 'Libra';
else if ($longitude < 271.26)
$zodiac = 'Scorpio';
else if ($longitude < 302.49)
$zodiac = 'Sagittarius';
else if ($longitude < 311.72)
$zodiac = 'Capricorn';
else if ($longitude < 348.58)
$zodiac = 'Aquarius';
else
$zodiac = 'Pisces';
// so longitude is not greater than 360!
if ($longitude > 360)
$longitude = $longitude - 360;
$moon['age'] = round($age, 2);
$moon['distance'] = round($distance, 2);
$moon['latitude'] = round($latitude, 2);
$moon['longitude'] = round($longitude, 2);
$moon['phase'] = $phase;
$moon['zodiac'] = $zodiac;
}
return $moon;
}
// normalize values to range 0...1
function normalize($v)
{
$v = $v - floor($v);
if ($v < 0)
{
$v++;
}
return $v;
}
?>


And to use it, you can do something like this

<?php
include('moon2.php');
$date = time();
$year = date('Y', $date);
$month = date('n', $date);
$day = date('j', $date);
$moon = moon_posit($month, $day, $year);
//debug results
echo '<pre>';
print_r($moon);
echo '</pre>';
if ($moon['errors'] === null)
{
//output and format what you want
}
else
{
//handle error how you want, perhaps give error message and then show today''s moon info
}
?>


I haven’t figured out how to get the percentage of illumination of the moon though.

Well one way to get around this is to setup an RSS feed for the data you are caching or outputting and access it with a query string such as “?rss=2.0″ or http://example.com/index.php?rss=2.0. Then you can check to see if the RSS variable was passed and output a RSS feed with just enough data for a feed, no need to put sensitive data in there or anything. I would suggest putting in a ttl node in the RSS feed and set it to something the aggregators like Google Reader, should obey (that way they hit your page more or less frequently, depending on your needs). The item portion of an RSS feed only needs a title or a description, although its probably a good idea to put some kind of guid in there (check the RSS 2.0 spec for more info on creating RSS feeds).

Anyway here is some sample code. It isn’t complete but gives you an idea what I mean.

if ($_GET['rss'] == 2.0)
{
//create RSS 2.0 feed
header('Content-Type: text/xml');
$output = '<' . '?xml version="1.0"?' . '>' . "\n";
$output .= '<rss version="2.0">' . "\n";
$output .= '<channel>' . "\n";
//...
//process your data and output it into RSS 2.0 format
//...
$output .= '</channel>' . "\n";
$output .= '</rss>';
}
else
{
//process your data as normal
}


Then to make sure the page is hit often, place your RSS feed into Google Reader or Bloglines or some other RSS aggregator. Then your site will be visited often and forced to update. No one else really needs to know about your RSS feeds, unless you want them to be public as well.

No need to have the W3C mess with their validator just to work with all the possible browser extensions. This would most likely introduce bugs and cause too much of a headache for them.

Here are 2 things you can do to get by the errors

1. Put all your CSS3 rules in a css3.css file and then when you validate everything in your regular .css files should pass and the css3.css should fail.
2. Or put a /*CSS3*/ comment for each CSS3 rule you have in your style sheet, so when it gives an error you know why. This would work best if you put each css3 rule on a separate line.

In my opinion it’s best to use the free virtual machines that Microsoft has for IE6, IE7 and IE8 beta 2. A few are on XP and another is on Vista, I recommend the XP versions, since they are smaller in filesize and will run much faster. The Virtual Machines expire after a few months, but so far Microsoft has been continuing to make new ones for free.

Then you need to get Virtual PC 2007 or if you’re on Windows 2000 you can use Virtual PC 2004 SP1, both of which are free.

Converting them for use on VMware products is easy, but you do need Virtual PC to create the *.vmc file (this holds the configuration). Once you have the vmc file you need to place it in the same folder as the vhd file and then you can use VMware Converter to convert it into a virtual machine you can use in VMware Player or VMware Server, which are all free products.

Of course you could always setup an old Windows 2000 machine, since the last version of Internet Explorer it can run is IE6. And if you are stuck on a Windows 2000 machine, you could always use these virtual machines and install Chrome or Safari, since neither work on Windows 2000. However, I wouldn’t spend too much time configuring the free virtual machines though, since they expire every few months.

Financial situations may pressure you to squeeze in another ad or your web stats prove video is hot, so the powers that be require you to have a video widget on the page. Another department requires you have a link to their content above the fold or someplace prominent with a icon or hideous color. People that use CMSes can’t see how the information looks as they enter it or if it’s consistent with the rest of the site, afterall most admins screens are rather plain. Thus, content that wasn’t originally planned or laid out in the initial design just gets dumped in.

So, what can you do?

• Filter out CSS and HTML (although sometimes people need the ability to create tables, or put in some YouTube code). You could possibly allow a few tags and then filter out the rest but be sure to remove style attributes.
• Setup your CSS to try to override any possible color or font changes (nothing is worse than having a site all in Verdana and then someone dumping in font tags using Lucida Handwriting or big ugly blocks of bold red text).
• Make rules or guidelines for entering data into your site.
• Suggest to users they should not use all uppercase for titles, let them know that CSS can transform the text for them (that way you if you redesign later you won’t have some titles in uppercase and others not so).
• Suggest alternatives to the bright yellow background colored box they want for video player.
• Add a Preview feature that shows them exactly what the data will look like on the live site.
• Check the dimensions and filesize of any images uploaded (resize and save them with backend code like PHP if possible or do the alternative with nasty HTML squashing and force them to be a certain size with the height and width attributes).
• Be sure they know any images that are uploaded need to look crisp (any really dark, red tinted, or blurry photos can make a good site look bad very quickly).

The first is from the original design the site had.

In this one I just use 2 images for the quotes, but no extra div for the closing quote, because I use the last-child pseudo-class.


blockquote {
margin:1.5em;
padding:5px 40px;
border-top:1px solid #eee;
border-bottom:1px solid #eee;
background:url(images/quotation_marks.gif) no-repeat left 5px;
color:#717f53;
min-height:30px;
}
blockquote p:last-child {background:url(images/quotation_marks_close.gif) no-repeat right bottom;}/*css3*/


The second is the one I use on the site right now. Instead of using images, I just use the css content property and set the value to open-quote for the before pseudo-class and close-quote for the after pseudo-class. I also add css rounded corners for some extra styling.


blockquote p {
padding:10px;
margin:10px;
}
blockquote:before, blockquote:after {
display:block;
cursor:default;
line-height:1em;
font-weight:bold;
font-size:1.6em;
color:#000;
font-family:Georgia, 'Times New Roman', serif;
}
blockquote:before {
content:open-quote;
}
blockquote:after {
text-align:right;
content:close-quote;
}
blockquote {
margin:20px;
padding:10px;
border:1px solid #eee;
line-height:1.4em;
color:#918e95;
-moz-border-radius:5px; -webkit-border-radius:5px;/*css3 rounded corners*/
}


This CSS may not work in older-browsers, but if the blockquote is indented with a border or set to another color, it should stand out enough to be ok.

I modified the latter (Moon Phase Calculation and used the first function listed on that page).

<?php
function moon_phase($year, $month, $day)
{
/*
modified from http://www.voidware.com/moon_phase.htm
*/
$c = $e = $jd = $b = 0;
if ($month < 3)
{
$year--;
$month += 12;
}
++$month;
$c = 365.25 * $year;
$e = 30.6 * $month;
$jd = $c + $e + $day - 694039.09; //jd is total days elapsed
$jd /= 29.5305882; //divide by the moon cycle
$b = (int) $jd; //int(jd) -> b, take integer part of jd
$jd -= $b; //subtract integer part to leave fractional part of original jd
$b = round($jd * 8); //scale fraction from 0-8 and round
if ($b >= 8 )
{
$b = 0;//0 and 8 are the same so turn 8 into 0
}
switch ($b)
{
case 0:
return 'New Moon';
break;
case 1:
return 'Waxing Crescent Moon';
break;
case 2:
return 'Quarter Moon';
break;
case 3:
return 'Waxing Gibbous Moon';
break;
case 4:
return 'Full Moon';
break;
case 5:
return 'Waning Gibbous Moon';
break;
case 6:
return 'Last Quarter Moon';
break;
case 7:
return 'Waning Crescent Moon';
break;
default:
return 'Error';
}
}
$timestamp = time();
echo moon_phase(date('Y', $timestamp), date('n', $timestamp), date('j', $timestamp));
?>


I haven’t been able to find out how to calculate the percentage for how lit up (full) the moon is yet though.

I converted the other code in another blog post. Calculating the Moon Phase Part 2

If you use SOAP there are many methods to grab the data, but if you use REST there are only 2. With REST you can either use DWMLgen which lets you get a little more specific information or NDFDgenByDay which is a little simpler and lets you pick either 12 hour or 24 hour increments (so you can get each day broken in half as in day and night or the full day). The response is sent back as XML for either method so you can format the data how you like.

For the example we are doing, we are going to keep it simple and use a single location, NDFDgenByDay and a 24 hourly period. We will also set it up so that we send the longitude and latitude for Austin, TX, the current date as the start date and request 7 days worth of data.

You’ll want to get the longitude of the location you want the forecast for. The simplest way is to use Google Maps and type in your city and state and search. Then put your cursor slightly below the green arrow, basically as soon as it is not linking to the arrow. Now double click and the map may shift slightly. Now click on the Link to this page text and you will get a box and copy whats in the first textfield. You’ll get a huge URL like the one below.

http://maps.google.com/maps?ie=UTF8&oe=utf-8&client=firefox-a&q=Austin,+TX,+USA&ll=30.270928,-97.742615&spn=0.432311,0.6427&z=11

What we want is the longitude and latitude. In that long URL you’ll see &ll= and after it will be the longitude and latitude separated by a comma. And in this case it is 30.270928,-97.742615.

So let’s make the request and write it to a file. Here is the PHP to do that.

<?php
//custom function to write a file
simple_write_file($filename, $data)
{
//write file
$fp = @fopen($filename, 'w'); //suppress error
if ($fp)
{
flock($fp, LOCK_EX);//lock file for writing
fwrite($fp, $data);
flock($fp, LOCK_UN);//release write lock
fclose($fp);
$output = '';
}
else
$output = 'Failed to open file.';
return $output;
}
$parameters = array('lat' => 30.270928, 'lon' => -97.742615, 'startDate' => gmdate('Y-m-d'), 'numDays' => 7, 'format' => urlencode('24 hourly'));
$data = file_get_contents('http://www.weather.gov/forecasts/xml/sample_products/browser_interface/ndfdBrowserClientByDay.php?&lat='.$parameters['lat'].'&lon='.$parameters['lon'].'&format='.$parameters['format'].'&startDate='.$parameters['startDate'].'&numDays='.$parameters['numDays']);
simple_write_file('forecast.xml', $data);//NOTE: this will write the error to the file if it encounters one, but this is just for testing purposes
?>


The NWS recommends to make a new request 15 minutes after the hour and to cache the data for an hour. So you’ll want to write the code to cache it, but for this example we can just check the file and see if it’s good and then play with that file without having to make requests each time. Now here is some PHP code using SimpleXML to parse through the data in that file.

<?php
$output = '';
//php5
if (file_exists('forecast.xml'))
{
$today = date('l');
$today_index = -1;
$xmlstr = file_get_contents('forecast.xml');
$xml = simplexml_load_string($xmlstr);
$xml_weather = $xml->data->parameters;//shorthand
$count = count($xml_weather->temperature->value);
$output .= '<ul id="weather_forecast">';
for($x = 0; $x < $count; $x++)
{
$output .= '<li>';
//convert time to timestamp
$timestamp = strtotime($xml->data->{'time-layout'}->{'start-valid-time'}[$x]);
$day = date('l', $timestamp);
//get the day of the week
$output .= '<strong class="day_of_week">';
if ($today == $day)
{
$output .= 'Today';
$today_index = $x + 1;
}
else if ($today_index == $x)
$output .= 'Tomorrow';
else
$output .= $day;
$output .= '</strong>';
//store it for shorthand multiple use
$condition = $xml_weather->weather->{'weather-conditions'}[$x]->attributes()->{'weather-summary'};
//icon image
$output .= ' ';
$output .= '<img src="';
$output .= basename($xml_weather-/>{'conditions-icon'}->{'icon-link'}[$x]);//get the filename, we are going to host the icons on our server
$output .= '" alt="' . htmlentities($condition, ENT_QUOTES) . '" />';//alt text is the condition
//conditions
$output .= ' ';
$output .= '<strong class="condition">';
$output .= $condition;
$output .= '</strong>';
//NOTE: 7th day low will usually be null, so dont bother showing the high
if ($x < 6)
{
//high and low
$output .= ' ';
$output .= '<span class="temperature">';
$output .= '<span class="temperature_high">' . $xml_weather->temperature[0]->value[$x] . '&deg;</span>';//high
$output .= ' / ';
$output .= '<span class="temperature_low">' . $xml_weather->temperature[1]->value[$x] . '&deg;</span>';//low
$output .= '';
}
//NOTE: precipitation is broken into 12hr periods and the 7th day's evening precipitation will usually be null
$output .= '';
}
$output .= '</ul>';
$output .= '<p class="credits">Weather by <a href="' . $xml->head->source->credit . '">NOAA</a></p>';
}
echo $output;
?>


The benefits to the NWS service are: you can make a request for up to 200 locations in one call, you can get weather from the past or several days ahead and use it on a commercial site.

Now combine this code with code I did before on getting current conditions and you one step closer to building your own portal. As I mentioned before, you can’t claim to have copyright on the data, but it is public domain information.

Here is some code for PHP5 (it uses SimpleXML) on doing this (assuming you’ve already grabbed the XML file from their site and have a way to cache it). It even has some code calculating the sunrise, sunset and civil twilight which PHP5 can do with date_sun_info() and since the XML file gives the date, latitude and longitude, you can calculate it dynamically.

//PHP5
if (file_exists('KADS.xml'))
{
$xmlstr = file_get_contents('KADS.xml');
$xml = simplexml_load_string($xmlstr);
$datetime = strtotime($xml->observation_time_rfc822);
$latitude = (float)$xml->latitude;
$longitude = (float)$xml->longitude;
$sun_info = date_sun_info(date('Y-n-j', $datetime), $latitude, $longitude);//calculate sunrise,sunset,...
echo '<ul id="current_conditions">';
echo '<li>' . date('l, F j, Y', $datetime) . '</li>';
echo '<li class="weather_loc">' . $xml->location . '</li>';
echo '<!--' . $xml->observation_time . '-->';
echo '<li><img src="' . $xml->icon_url_base . $xml->icon_url_name . '" alt="' . $xml->weather . '" /></li>';
echo '<li class="weather_temp"><strong>' . $xml->temp_f . '&deg;' . '</strong></li>';
echo '<li class="weather_sum"><strong>' . $xml->weather . '</strong></li>';
echo '<li>Wind: <strong>' . $xml->wind_dir . ' ' . round($xml->wind_mph) . ' mph</strong></li>';
echo '<li>Humidity: <strong>' . $xml->relative_humidity . '%</strong></li>';
if ($xml->heat_index_f != 'NA')
echo '<li>Heat Index: <strong>' . $xml->heat_index_f . '</strong></li>';
if ($xml->windchill_f != 'NA')
echo '<li>Windchill: <strong>' . $xml->windchill_f . '</strong></li>';
echo '<li>Barometer: <strong>' . $xml->pressure_in . '&quot;</strong></li>';
echo '<li>Visibility: <strong>' . $xml->visibility_mi . ' mi</strong></li>';
echo '<li>Dewpoint: <strong>' . $xml->dewpoint_f . '&deg;</strong></li>';
echo '<li class="weather_credit">weather by <a href="' . $xml->credit_URL . '" title="' . $xml->credit . '">NOAA</a></li>';
echo '</ul>';
echo '<ul id="sunrise_sunset">';
echo '<li>Sunrise: <strong>' . date('g:i a', $sun_info['sunrise']) . '</strong> <span class="civil_twilight">Civil Twilight: <strong>' . date('g:i a', $sun_info['civil_twilight_begin']) . '</strong></span></li>';
echo '<li>Sunrise: <strong>' . date('g:i a', $sun_info['sunset']) . '</strong> <span class="civil_twilight">Civil Twilight: <strong>' . date('g:i a', $sun_info['civil_twilight_end']) . '</strong></span></li>';
echo '</ul>';
}


You will probably want to cache that output once you have it formatted how you like.