/**
* Genera un gráfico con todas las combinaciones de gráficas entre todas las "x" y la "y", ej: f(x1,x2) = y
* generará un gráfico con 6 gráficas (x1,y), (x1,x2), (x2,y), (x2,x1), (y,x1), (y,x2).
* f(x1,x2,x3) = y generará 12 gráficas.
* Las gráficas maximizaran el espacio de dibujo disponible, mostrarán la línea de tendencia, y la fórmula con ß0
* ß1 y R2
*
* @param string $filename
* @return string
*/
public function generateDraw($filename = null)
{
$boxes = $this->independentVars->getNumRows() + $this->dependentVars->getNumRows();
$drawSize = ($this->drawBoxSize + 1) * $boxes - 2;
$image = imagecreatetruecolor($drawSize, $drawSize);
$color = imagecolorallocate($image, 255, 255, 255);
imagefilledrectangle($image, 0, 0, $drawSize, $drawSize, $color);
$color = imagecolorallocate($image, 255, 0, 0);
for ($a = 1; $a < $boxes; $a++) {
$pos = ($this->drawBoxSize + 1) * $a - 1;
imageline($image, 0, $pos, $drawSize, $pos, $color);
imageline($image, $pos, 0, $pos, $drawSize, $color);
}
for ($a = 0; $a < $boxes; $a++) {
if ($a == 0) {
$text = isset($this->dependentTitle[0]) ? $this->dependentTitle[0] : 'Y';
} else {
$text = isset($this->independentTitles[$a - 1]) ? $this->independentTitles[$a - 1] : 'X' . $a;
}
$pos = $this->drawBoxSize * $a;
$this->imageTextCentered($image, $color, 45, $this->fontSize, $this->fontName, $pos, $pos, $pos + $this->drawBoxSize, $pos + $this->drawBoxSize, $text);
}
$colorPoint = imagecolorallocate($image, 0, 0, 255);
$colorLine = imagecolorallocate($image, 0, 255, 0);
$colorFormula = imagecolorallocate($image, 64, 64, 64);
for ($a = 0; $a < $boxes; $a++) {
for ($b = 0; $b < $boxes; $b++) {
if ($a == $b) {
continue;
}
if ($a == 0) {
$x = $this->dependentVars->getRow(1);
} else {
$x = $this->independentVars->getRow($a);
}
if ($b == 0) {
$y = $this->dependentVars->getRow(1);
} else {
$y = $this->independentVars->getRow($b);
}
$this->drawDotPlot($image, $colorPoint, $colorLine, $colorFormula, ($this->drawBoxSize + 1) * $a, ($this->drawBoxSize + 1) * $b, ($this->drawBoxSize + 1) * ($a + 1) - 2, ($this->drawBoxSize + 1) * ($b + 1) - 2, $x, $y);
}
}
if (is_null($filename)) {
$filename = 'test.png';
}
imagepng($image, $filename);
return $filename;
}
