/**
* creates a line chart
* @param array $data data input
* @param int $width graphic width
* @param int $height graphic height
* @param array $color lines colors
* @param array $style lines style (filled or line)
* @param int $zLine a "zero" line
* @param array $legende caption
*/
public function lineChart($data, $width, $height, $color = null, $style = null, $zLine = null, $legende = null)
{
// error if datatype is wrong
if (!is_array($data)) {
echo 'wrong datatype for variable $data';
return false;
} else {
if (!is_numeric($width)) {
echo 'wrong datatype for variable $width';
return false;
} else {
if (!is_numeric($height)) {
echo 'wrong datatype for variable $height';
return false;
}
}
}
// globalize some optional variables
if (isset($zLine)) {
$this->zLine = $zLine;
} else {
unset($this->zLine);
}
if (isset($legende)) {
$this->legende = $legende;
} else {
unset($this->legende);
}
if (isset($color)) {
$this->lColors = $color;
} else {
unset($this->lColors);
}
if (isset($style)) {
$this->fills = $style;
} else {
unset($this->fills);
}
// globalize some required variables
$pad = 8;
// standard top and bottom padding
$this->width = $width;
$this->height = $height;
$this->imgh = $height + $pad;
// add padding to prevent elements from being ouside the image
$this->data = $data;
$this->numLines = count($this->data);
// number of graphs = number of datasets in $data
$this->lenSet = 0;
$this->yMax = 0;
foreach ($this->data as $set) {
if (count($set) > $this->lenSet) {
$this->lenSet = count($set) - 1;
// find out the number of datapoints in a set
}
if (max($set) > $this->yMax) {
$this->yMax = max($set);
// find out the highest value
}
if (!isset($this->yMin)) {
// cant set this one before, since a sets lowest value may be 2 insted of -2
$this->yMin = min($set);
// find out the lowest value
} else {
if ($this->yMin > min($set)) {
$this->yMin = min($set);
}
}
}
if ($this->yMin < 0) {
// if the range of data values goes beyond zero ...
$pl = abs($this->yMin);
// we have to determine the whole range by this
} else {
$pl = 0;
// otherwise we start by zero (which may not be a good idea ?!)
}
$h = $this->yMax + $pl;
// $h effectively is the datasets range
$h = $h === 0 ? 1 : $h;
// (modified by zhenglei: to set range to 1 when range is zero)
// initiate drawing class
parent::Init($this->width, $this->imgh, "lines");
parent::imgFill("white", 1, 1);
$dsnum = 0;
if ($this->lenSet > 0) {
// (modified by zhenglei: if lenSet smaller than 0, just plot a white picture)
foreach ($this->data as $set) {
// we are on a set level
$i = 0;
unset($lx, $ly);
foreach ($set as $dp) {
// we are on single data value level
// X of course is the image width divided by set length multiplied by index of current value in set
$x = $i * ($this->width / $this->lenSet);
$yp = $dp + $pl;
// since we tricked in getting the whol set range, we must add the $pl we added above to the Y value
$y = $this->height - $yp * ($this->height / $h);
// ..and continue analogue to X
$y += $pad / 2;
// applies padding
if (isset($lx)) {
// if we are not at the first value in the set we start drawing the line from LX / LY to X / Y
parent::imgLine($lx, $ly, $x, $y, $this->lColors[$dsnum]);
}
self::featPoint($x, $y, $dsnum, $i);
// add feature point here if they were given
$lx = $x;
// saves the current values x and y ...
$ly = $y;
// since we will need it to draw from there to the next values XY
$i++;
}
if (isset($this->fills)) {
$s = $this->fills[$dsnum];
if ($s == "filled") {
// fill the space beneath the graph if needed
parent::imgFill($this->lColors[$dsnum], 1, $this->height, $this->lColors[$dsnum]);
}
}
$dsnum++;
}
}
// add zero line if given
if (isset($this->zLine)) {
$y = $this->height - ($this->zLine + $pl) * ($this->height / $h);
parent::imgLine(0, $y, $this->width, $y, "black");
}
}
