Class CanvasScale
(Defined in: jpgraph_canvtools.php : 24)

CanvasScale

Set()
Translate()
TranslateX()
TranslateY()
__construct()

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

CanvasScale ::
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

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);

CanvasScale ::
Translate($x, $y)
Translate a point to absolute screen coordinates

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

Description:
Translate a point to absolute screen coordinates
See also:

- CanvasScale::TranslateX()
- CanvasScale::TranslateY()

Example:

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

CanvasScale ::
TranslateX($x)
Translate X-coordinate

Argument | Default | Description
--- | --- | ---
$x |  | X-value

Description:
Translate X-value into absolute screen coordinates
See also:

- CanvasScale::Translate()

CanvasScale ::
TranslateY($y)
Translate Y-value to absolute screen coordinates

Argument | Default | Description
--- | --- | ---
$y |  | Y-value

Description:
Translate Y-value to absolute screen coordinates
See also:

- CanvasScale::Translate()

CanvasScale ::
__construct($graph, $xmin, $xmax, $ymin, $ymax)
Define a scale for canvas graphs

Argument | Default | Description
--- | --- | ---
$graph |  | No description available
$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()