CLASS CanvasScale

(Defined in: jpgraph_canvtools.php : 24)

CanvasScale

CanvasScale()
Set()
Translate()
TranslateX()
TranslateY()

Class usage and Overview

This class defines a scale which is meant to be used with canvas graphs to make it possibles to pecify a more convinient scale compared to absoilute pixels coordinates.
This will also let you scale the canvas without any coordinate changes.

Class Methods

function CanvasScale(&$graph,$xmin,$xmax,$ymin,$ymax)

Define a scale for canvas graphs

Argument Default Description

&$graph Canvas graph

$xmin 0 Min X-value for scale

$xmax 10 Max X-value for scale

$ymin 0 Min Y-value for scale

$ymax 10 Max Y-value for scale

Argument	Default	Description
&$graph		Canvas graph
$xmin	0	Min X-value for scale
$xmax	10	Max X-value for scale
$ymin	0	Min Y-value for scale
$ymax	10	Max Y-value for scale

Description

Define a scale for canvas graphs. Note the scale values is optionally in this call. The may be later set witha call to the Set() method.

See also

CanvasScale::Set

function Set($xmin,$xmax,$ymin,$ymax)

Specify scale to use

Argument Default Description

$xmin 0 Min X value

$xmax 10 Max X-value

$ymin 0 Min Y-value

$ymax 10 Max Y-value

Argument	Default	Description
$xmin	0	Min X value
$xmax	10	Max X-value
$ymin	0	Min Y-value
$ymax	10	Max Y-value

Description

SPecify min/max values for scale.

Example

// Setup a basic canvas we can work
$g = new CanvasGraph(400,200,'auto');
$g->SetMargin(5,11,6,11);
$g->SetShadow();
$g->SetMarginColor("teal");

// We need to stroke the plotarea and margin before we add the
// text since we otherwise would overwrite the text.
$g->InitFrame();

// Create a new scale
$scale = new CanvasScale($g);
$scale->Set(0,$xmax,0,$ymax);

function Translate($x,$y)

Translate a point to absolute screen coordinates

Argument Default Description

$x X-value

$y Y-value

Argument	Default	Description
$x		X-value
$y		Y-value

Description

Translate a point to absolute screen coordinates

Example

list($xt,$yt) = $scale->Translate($x,$y);
$graph->img->Point($xt,$yt);

function TranslateX($x)

Translate X-coordinate

Argument Default Description

$x X-value

Argument	Default	Description
$x		X-value

Description

Translate X-value into absolute screen coordinates

See also

CanvasScale::Translate

function TranslateY($y)

Translate Y-value to absolute screen coordinates

Argument Default Description

$y Y-value

Argument	Default	Description
$y		Y-value

Description

Translate Y-value to absolute screen coordinates

See also

CanvasScale::Translate