advanced php function

soloWebDev · #1 (**permalink**) 05-08-07, 04:56 PM

This is the line i am having trouble with.
echo distance("41.740963" , "-87.80435", "'.$selectedlat.'" , "'.$selectedlon.'" , "m") . " miles<br>";

I am wondering if i am calling these wrong, in this which is above this function, the lat and lon are being displayed correctly.

PHP Code:


			
$selectedlat = $_POST['lattitude'];

$selectedlon = $_POST['longitude']; 

<td>".$selectedlat."</td>                         <td>".$selectedlon."</td>

but when i try to plug them into the function, they do not work.

PHP Code:


			
function distance($lat1, $lon1, $lat2, $lon2, $unit) { 



$theta = $lon1 - $lon2; 

$dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta)); 

$dist = acos($dist); 

$dist = rad2deg($dist); 

$miles = $dist * 60 * 1.1515;

$unit = strtoupper($unit);



if ($unit == "K") {

return ($miles * 1.609344); 

} else if ($unit == "N") {

return ($miles * 0.8684);

} else {

return $miles;

}

}

echo distance("41.740963" , "-87.80435", "'.$selectedlat.'" , "'.$selectedlon.'" ,  "m") . " miles<br>";

echo distance(41.740963, -87.80435, 41.66916, -87.73688, "m") . " miles<br>";

echo distance(41.740963, -87.80435, 41.66916, -87.73688, "k") . " kilometers<br>";

echo distance(41.740963, -87.80435, 41.66916, -87.73688, "n") . " nautical miles<br>";

UnrealEd · #2 (**permalink**) 05-08-07, 05:05 PM

this is how you should call the function:

PHP Code:


			
echo distance(41.740963 , -87.80435, $selectedlat , $selectedlon,  "m") . " miles<br>";

you don't need to convert the variables to string first, you can pass them to the function right away

soloWebDev · #3 (**permalink**) 05-08-07, 05:16 PM

UnrealEd, Thanks for responding so quickly.
Any thoughts why it still might not be working?
Any thing you might suggest in order for this to work?

UnrealEd · #4 (**permalink**) 05-08-07, 05:55 PM

are you recieving any errors? if not, place this on top of your script:

PHP Code:


			
ini_set('display_errors', '1');
error_reporting(E_ALL);

this will cause php to display all errors

i don't know the formula to calculate the distance across a sphere's surface by hard, so i don't know if you have an error in there, but i think not

job0107 · #5 (**permalink**) 05-08-07, 11:32 PM

I don't know if your math is correct or if your answers are correct. But for whatever it is, this does calculate the values submitted and gives you the results. I don't know what precision you need so I set it to 5 decimals.

PHP Code:


			
<?php
$selectedlat = $_POST["lattitude"];
$selectedlon = $_POST["longitude"];
echo "<table><tr><td>". $selectedlat."</td><td>".$selectedlon."</td></tr></table>";
function distance($lat1, $lon1, $lat2, $lon2, $unit)
{
 $theta = $lon1 - $lon2;
 $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
 $dist = acos($dist);
 $dist = rad2deg($dist);
 $miles = $dist * 60 * 1.1515;
 $unit = strtoupper($unit);
 if ($unit == "K")
 {
  return ($miles * 1.609344);
  }
 else if ($unit == "N")
 {
  return ($miles * 0.8684);
  }
 else
 {
  return $miles;
  }
 }
if(!$selectedlat || !$selectedlon)
{
 echo "<form action='#' method='post'>";
 echo "Enter Lattitude : <input type='text' name='lattitude'><br>";
 echo "Enter Longitude : <input type='text' name='longitude'><br>";
 echo "<input type='submit' value='Submit'>";
 echo "</form>";
 }
else
{
 echo round(distance(41.740963 , -87.80435, $selectedlat, $selectedlon,  "m"), 5) . " miles<br>";
 echo round(distance(41.740963, -87.80435, 41.66916, -87.73688, "m"), 5) . " miles<br>";
 echo round(distance(41.740963, -87.80435, 41.66916, -87.73688, "k"), 5) . " kilometers<br>";
 echo round(distance(41.740963, -87.80435, 41.66916, -87.73688, "n"), 5) . " nautical miles<br>";
 }
?>

Obviously your form must be functioning properly if you are able to display the posted values.

soloWebDev · #6 (**permalink**) 05-09-07, 10:58 AM

Thank you to everyone who helped out, here is the completed working code. Thanks again, really great team work by everyone. Which I have noticed is how this forum, stands out beyond the others. Everyuone works well with everyone else, and the forum is filled with inteligent, nice, coders. Thanks again.

PHP Code:


			
<?php

$selectedState = $_POST['state'];

$selectedCity = $_POST['city'];



// Lattitude, Longitude Selection

$qL = "SELECT lattitude, longitude  FROM table WHERE city = '$selectedCity'";

$rL = mysql_query($qL) or die("Invalid query: $qL");

while($data = mysql_fetch_array($rL))

{

$selectedlat2 = $data['lattitude'];

$selectedlon2 = $data['longitude'];

}



//State Selection

if(!$selectedCity)

{

echo "<div>";

echo "<form name='theForm' action='#' method='post'>";

$qS = "SELECT DISTINCT state FROM table ORDER BY state";

$$rS = mysql_query($qS) or die("Invalid query: $qS");

echo "<select name='state' onchange='theForm.submit()'>";

echo "<option value=''>Select a state</option>";

while($data = mysql_fetch_array($$rS))

{

if($data['state'] == $selectedState)

{

echo "<option value='".$data['state']."' SELECTED>".$data['state']."</option>";

}

else

{

echo "<option value='".$data['state']."'>".$data['state']."</option>";

}

}

echo "</select>";



//City & ZIP Selection

if($selectedState)

{

$qC = "SELECT city, lattitude, longitude  FROM table WHERE state = '$selectedState' ORDER BY city";

$$rC = mysql_query($qC) or die("Invalid query: $qC");

echo "<select name='city' onchange='theForm.submit()'>";

echo "<option value=''>Select a city</option>";

while($data = mysql_fetch_array($$rC))

{

echo "<option value='".$data['city']."'>".$data['city']."</option>";

//echo "<input type='hidden' value='".data['zip_Code']."'>"; 

}

echo "</select>";

echo "<input id='temp_state' name='temp_state' type='hidden' value='$selectedState'>";

echo "<input id='temp_city' name='temp_city' type='hidden' value='$selectedCity'>";

echo "<input id='temp_lattitude' name='temp_lattitude2' type='hidden' value='$selectedlat2'>";

echo "<input id='temp_longitude' name='temp_longitude2' type='hidden' value='$selectedlon2'>";

}         

echo "</form>";

echo "</div>";

}

else

{

echo "<table>

<tr>

<td>State</td>

<td>City</td>

<td>lat</td>

<td>lon</td>

</tr>

<tr>

<td>".$selectedState."</td>

<td>".$selectedCity."</td>

<td>".$selectedlat2."</td>

<td>".$selectedlon2."</td>

</tr>

</table>";



echo "<table><tr><td>".$selectedCity."</td><td>".$selectedlat2."</td><td>".$selectedlon2."</td></tr></table>";

function distance($lat1, $lon1, $lat2, $lon2, $unit)

{

$theta = $lon1 - $lon2;

$dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));

$dist = acos($dist);

$dist = rad2deg($dist);

$miles = $dist * 60 * 1.1515;

$unit = strtoupper($unit);

if ($unit == "K")

{

return ($miles * 1.609344);

}

else if ($unit == "N")

{

return ($miles * 0.8684);

}

else

{

return $miles;

}

}

echo round(distance(41.740963 , -87.80435, $selectedlat2, $selectedlon2,  "m"), 1) . " miles<br>";



if($selectedState && $selectedCity && $selectedlat2 && $selectedlon2)

{

echo "<script>clear_form()</script>";

}



}



?>

The js

Code:

<script>
function clear_form()
{
 document.getElementById('temp_state').value = '';
 document.getElementById('temp_city').value = '';
 document.getElementById('temp_lattitude2').value = '';
 document.getElementById('temp_longitude2').value = '';
 }
</script>

Please reference this thread for the other half of this puzzle.
LINK

job0107 · #7 (**permalink**) 05-09-07, 11:47 PM

If I might make a few suggestions, The program as you have it at the moment, will not let you select more than one state. I have made a few changes that should fix the problems.

PHP Code:


			
<?php
function distance($lat1, $lon1, $lat2, $lon2, $unit)
{
 $dist = rad2deg(acos(sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($lon1 - $lon2))));
 $miles = $dist * 69.09;
 $unit = strtoupper($unit);
 return $miles = ($unit == "K") ? ($miles *= 1.609344) : ($unit == "N") ? ($miles *= .8684) : $miles;
 }
$selectedState = $_POST["temp_state"];if(!$selectedState){$selectedState = $_POST["state"];}
$selectedCity = $_POST["temp_city"];if(!$selectedCity){$selectedCity = $_POST["city"];}
//State Selection
if(!$selectedCity)
{
 echo "<div>";
 echo "<form name='theForm' action='#' method='post'>";
 $qS = "SELECT DISTINCT state FROM table ORDER BY state";
 $rS = mysql_query($qS) or die("Invalid query: $qS");
 echo "<select id='state' name='state' onchange='theForm.submit()'>";
 echo "<option value=''>Select a state</option>";
 while($data = mysql_fetch_array($rS))
 {
  if($data['state'] == $selectedState)
  {
   echo "<option value='".$data['state']."' SELECTED>".$data['state']."</option>";
   }
  else
  {
   echo "<option value='".$data['state']."'>".$data['state']."</option>";
   }
  }
 echo "</select>";
 //City & ZIP Selection
 if($selectedState)
 {
  $qC = "SELECT city, lattitude, longitude  FROM table WHERE state = '$selectedState' ORDER BY city";
  $rC = mysql_query($qC) or die("Invalid query: $qC");
  echo "<select id='city' name='city' onchange='theForm.submit()'>";
  echo "<option value=''>Select a city</option>";
  while($data = mysql_fetch_array($rC))
  {
   echo "<option value='".$data['city']."'>".$data['city']."</option>";
   }
  echo "</select>";
  echo "<input id='temp_state' name='temp_state' type='hidden' value='$selectedState'>";
  echo "<input id='temp_city' name='temp_city' type='hidden' value='$selectedCity'>";
  }
 echo "</form>";
 echo "</div>";
}
else
{
 // Lattitude, Longitude Selection
 $qL = "SELECT lattitude, longitude  FROM table WHERE city = '$selectedCity'";
 $rL = mysql_query($qL) or die("Invalid query: $qL");
 while($data = mysql_fetch_array($rL))
 {
  $selectedlat2 = $data['lattitude'];
  $selectedlon2 = $data['longitude'];
  }
 echo "<table>
        <tr>
         <td>State</td>
         <td>City</td>
         <td>lat</td>
         <td>lon</td>
        </tr>
        <tr>
         <td>".$selectedState."</td>
         <td>".$selectedCity."</td>
         <td>".$selectedlat2."</td>
         <td>".$selectedlon2."</td>
        </tr>
       </table>
       <table>
        <tr>
         <td>".$selectedCity."</td>
         <td>".$selectedlat2."</td>
         <td>".$selectedlon2."</td>
        </tr>
       </table>";
 echo round(distance(41.740963 , -87.80435, $selectedlat2, $selectedlon2,  "m"), 1) . " miles<br>";
 echo "<script>clear_form()</script>";
 echo "<p><button onclick='theForm.submit()'>Make another selection?</button></p>";
 }
?>

And the js

Javascript Code:

<script>
function clear_form()
{
 document.getElementById('temp_state').value = '';
 document.getElementById('temp_city').value = '';
 document.getElementById('state').value = '';
 document.getElementById('city').value = '';
 }
</script>