someutilityfunctionsinphp

PHP Database functions

/** getEnumFieldVals()

*get the enum values for an enum field from a table

*/

function getEnumFieldVals($db,$table,$field){

    // Get the Status Enum values

    $query="show columns FROM $table like '$field'";

    $res=$db->query($query);

    handleErrors(&$db);

    $row=$res->fetchRow(DB_FETCHMODE_ASSOC);

    //a regex way to do this is as follows. I am new to regex, so I used my own technique as below

    //feel free to try this regex code out: Binod

        //$regex = "/'(.*?)'/";

        //preg_match_all( $regex , $row['Type'], $enum_array );

        //print_r($enum_array);echo "<Br>";

        //$enum_fields = $enum_array[1];

        //print_r($enum_fields); echo "<Br>";

    $type=$row['Type'];

    $type=str_replace('(','',$type);

    $type=str_replace(')','',$type);

    $type=str_replace('enum','',$type);

    $enum_types=split(',',$type);

    return $enum_types;

}

/**

* function getComboBoxHTMLForField($name,$db,$table,$field,$value)

* Code to generate a database enabled combo box with a given $name

*given a database object $db, $table and $field name,

*returns the html for a combo box which lists the enum values of the enum field $field

*and selects the currently active value, passed as $value

* requires the function getEnumFieldVals, to fetch the enumeration values

*/

function getComboBoxHTMLForField($name,$db,$table,$field,$value){

    $enum_Values=getEnumFieldVals($db,$table,$field);

    $comboBoxHTML="<select name='$name'>";

    foreach($enum_Values as $curValue){

              $detectCurValue= ($curValue=="'$value'");

              $curValue=str_replace("'","",$curValue);

            $comboBoxHTML .="<option value='$curValue'";  

            if($detectCurValue==1)$comboBoxHTML .=" selected ";   

            $comboBoxHTML .=">$curValue </option>";

      }

    $comboBoxHTML .="</select>";

    return $comboBoxHTML;

}

PHP Interpolation functions

//SOME INterpolation functions - Binod Pant 03/29/2006

//==========================================================

        //insert linearly interpolated values into this array at location x_index, based on the two values y0 and y1 at x0 and x1

        //uses the function interpolate

        function get_interp_values($x0,$x1,$y0,$y1,$deltaX){

                $yret=array();

                echo "X1 = $x1 and X2 = $x2, Y1= $y1 and Y2= $y2 <br>";

                $num_points=floor(($x1-$x0)/$deltaX);   

                $m=$num_points-1; //no of points to insert

                echo "no of points = $m <br>";

                //echo $m."<br>";

                for ($i=1;$i<=$m;$i++){

                      $xi=$x0+$deltaX * $i;

                      $yret[$i-1]=interpolate($x0,$x1,$y0,$y1,$xi);

                      //echo "$i value between $x0,$y0 and $x1,$y1  = ".$yret[$i-1]."<br>";

                  }

            return $yret;

        }

        function interpolate($x0,$xN,$y0,$yN,$xDesired){

            $yDesired = $y0 + ($yN-$y0) / ($xN-$x0) * ($xDesired-$x0);

            return $yDesired;

        }

        //Insert at $pos array $items inside array $source

        function array_insert($source, $pos, $items){

           $sub1 = array_slice($source, 0, $pos);

           $sub2 = array_slice($source, $pos);

           return array_merge($sub1,$items,$sub2);

        }

        function strip_infs($xvals='',$array){

            $n=count($array)-1;

            while(is_infinite($array[$n])){$n--;}

            $m=0;

            while(is_infinite($array[$m])){$m++;}

            //echo $n; echo "<br>";

            $j=0;

            for($i=$m;$i<$n+1;$i++,$j++){

                $retarr[$j]=$array[$i];

                $retXarr[$j]=$xvals[$i];

            }

            return array($retXarr,$retarr);

        }

        function strip_leading_blanks($array){

             $n=0;

            while($array[$n]===''){$n++;}

            //echo $n; echo "<br>";

            $j=0;

            for($i=$n;$i<count($array);$i++,$j++)

                $retarr[$j]=$array[$i];

            return $retarr;

        }

        //a function to calculate $N points that lie on a straight line between two points $yBegin and $yEnd

        //this is not currently  used

        function getNPointsOnTheLine($yBegin,$yEnd,$N){

            $intermediate_points=array();

            $totalN=$N+1; //including the end points

            $deltaY=($yEnd-$yBegin)/$totalN; //gives the delta value to increment or decrement x

            for($i=0;$i<$N;$i++){

                $intermediate_points[$i]=$yBegin + ($i+1)*$deltaY;

            }

            return $intermediate_points;

        }