/**
* Apply the dataset to the axis.
*
* This calculates the order of the categories, which is very important
* for fx. line plots, so that the line does not "go backwards", consider
* these X-sets:<p>
* 1: (1, 2, 3, 4, 5, 6)<br>
* 2: (0, 1, 2, 3, 4, 5, 6, 7)<p>
* If they are not ordered, but simply appended, the categories on the axis
* would be:<p>
* X: (1, 2, 3, 4, 5, 6, 0, 7)<p>
* Which would render the a line for the second plot to show incorrectly.
* Instead this algorithm, uses and 'value- is- before' method to see that
* the 0 is before a 1 in the second set, and that it should also be before
* a 1 in the X set. Hence:<p>
* X: (0, 1, 2, 3, 4, 5, 6, 7)
*
* @param Image_Graph_Dataset $dataset The dataset
* @access private
*/
function _applyDataset(&$dataset)
{
$newLabels = array();
$allLabels = array();
$dataset->_reset();
$count = 0;
$count_new = 0;
while ($point = $dataset->_next()) {
if ($this->_type == IMAGE_GRAPH_AXIS_X) {
$data = $point['X'];
} else {
$data = $point['Y'];
}
if (!isset($this->_labels[$data])) {
$newLabels[$data] = $count_new++;
//$this->_labels[] = $data;
}
$allLabels[$data] = $count++;
}
if (count($this->_labels) == 0) {
$this->_labels = $newLabels;
} elseif (is_array($newLabels) && count($newLabels) > 0) {
// get all intersecting labels
$intersect = array_intersect(array_keys($allLabels), array_keys($this->_labels));
// traverse all new and find their relative position withing the
// intersec, fx value X0 is before X1 in the intersection, which
// means that X0 should be placed before X1 in the label array
foreach ($newLabels as $newLabel => $id) {
$key = $allLabels[$newLabel];
reset($intersect);
$this_value = false;
// intersect indexes are the same as in allLabels!
$first = true;
while ((list($id, $value) = each($intersect)) && $this_value === false) {
if ($first && $id > $key) {
$this_value = $value;
} elseif ($id >= $key) {
$this_value = $value;
}
$first = false;
}
if ($this_value === false) {
// the new label was not found before anything in the
// intersection -> append it
$this->_labels[$newLabel] = count($this->_labels);
} else {
// the new label was found before $this_value in the
// intersection, insert the label before this position in
// the label array
// $key = $this->_labels[$this_value];
$keys = array_keys($this->_labels);
$key = array_search($this_value, $keys);
$pre = array_slice($keys, 0, $key);
$pre[] = $newLabel;
$post = array_slice($keys, $key);
$this->_labels = array_flip(array_merge($pre, $post));
}
}
unset($keys);
}
$labels = array_keys($this->_labels);
$i = 0;
foreach ($labels as $label) {
$this->_labels[$label] = $i++;
}
// $this->_labels = array_values(array_unique($this->_labels));
$this->_calcLabelInterval();
}
