<?php
require_once('./polynomial/XY_Plot.php' );

function plotRenderData( $data, $color )
{
    global $plot;

    $plot->resetData();
    foreach ( $data as $point )
        $plot->addData( $point[ 0 ], $point[ 1 ] );

    $plot->setColor( $color );

    $plot->autoScaleX_MinMax( 0 );
    $plot->autoScaleY_MinMax( 1 );
}
function textCallback( $Value )
{
    return number_format( $Value, 1 );
}
function plotAddScale()
{
    global $plot;
    global $X_MajorScale;
    global $X_MinorScale;
    global $Y_MajorScale;
    global $Y_MinorScale;
    global $colorMap;

    // Setup and draw minor horizontal scale (right to left).
    $plot->SetX_MinorDivisionScale( $X_MinorScale );
    $plot->SetX_MinorDivisionColor( $colorMap[ "Gray90" ] );
    $plot->DrawX_MinorDivisions();

    // Setup and draw minor vertical scale (top to bottom).
    $plot->SetY_MinorDivisionScale( $Y_MinorScale );
    $plot->SetY_MinorDivisionColor( $colorMap[ "Gray90" ] );
    $plot->DrawY_MinorDivisions();

    //----------------------------------
    // Setup and draw major horizontal scale (right to left).
    //----------------------------------

    // Extend lines 5 pixels past margins for label.
    $plot->SetX_MajorDivisionExtention( 5 );

    // Scale.
    $plot->SetX_MajorDivisionScale( $X_MajorScale );

    // Division lines are blue.
    $plot->SetX_MajorDivisionColor( $colorMap[ "Gray80" ] );

    // Text labels are dark gray.
    $plot->SetX_MajorDivisionTextColor( $colorMap[ "Black" ] );
    $plot->SetX_MajorTextCallback( "textCallback" );

    // Draw it.
    $plot->DrawX_MajorDivisions();

    //----------------------------------
    // Setup and draw major vertical scale (top to bottom)
    //----------------------------------

    // Extend lines 5 pixels past margins for label.
    $plot->SetY_MajorDivisionExtention( 5 );

    // Scale.
    $plot->SetY_MajorDivisionScale( $Y_MajorScale );

    // Divisions in dark gray.
    $plot->SetY_MajorDivisionColor( $colorMap[ "Gray80" ] );
    $plot->SetY_MajorTextCallback( "textCallback" );

    // Lables in dark gray.
    $plot->SetY_MajorDivisionTextColor( $colorMap[ "Black" ] );

    // Draw it.
    $plot->DrawY_MajorDivisions();
}
function plotRenderRegression( $regression, $coefficients, $min, $max, $color )
{
    global $plot;
    global $imageWidth;
    global $leftMargin;
    global $rightMargin;

    $plot->resetData();

    $frameWidth = $imageWidth - $leftMargin - $rightMargin;
    for ( $xIndex = 0; $xIndex < $frameWidth; ++$xIndex )
    {
        $x = $xIndex * ( $max - $min ) / $frameWidth + $min;
        $y = $regression->interpolate( $coefficients, $x );
        $plot->addData( $x, $y );
    }

    $plot->setColor( $color );
    $plot->renderWithLines();

}

?>