php - Get color value from numeric values -
i need projet color value. explain, have datas , each data must represented color.
the red color maximum, , blue minimum , green middle value. kind of heatmap.
so, need have function returning right color.
i tried :
function datatocolor($min, $max, $value) { $half = (($min + $max) / 2); if ($value > $half) { $r = (255 * ($value+$min-$half)) / $half; $g = 255 - $r; $b = 0; } else { $b = (255 * ($half-$value+$min)) / $half; $g = 255 - $b; $r = 0; } $color = array(intval($r), intval($g), intval($b)); return $color; } but, red , blue, , never green ... tried lot of operations, must stupid don't find right operation ... in advance !
i'm not php expert, far can tell, problem isn't code block. tested algorithm in java sure, , looks correct:
public static void main(string[] args) { int min = 0; int max = 10; int half = (min + max) / 2; int r, g, b; // cycling through values completeness' sake. (int value = 0; value <= 10; value++) { if (value > half) { r = (255 * (value + min - half)) / half; g = 255 - r; b = 0; } else { b = (255 * (half - value + min)) / half; g = 255 - b; r = 0; } system.out.println("value: " + value + " - " + new color(r, g, b)); } the output expect -- pure blue @ minimum, pure green @ middle, , pure red @ maximum:
value: 0 - java.awt.color[r=0,g=0,b=255] value: 1 - java.awt.color[r=0,g=51,b=204] value: 2 - java.awt.color[r=0,g=102,b=153] value: 3 - java.awt.color[r=0,g=153,b=102] value: 4 - java.awt.color[r=0,g=204,b=51] value: 5 - java.awt.color[r=0,g=255,b=0] value: 6 - java.awt.color[r=51,g=204,b=0] value: 7 - java.awt.color[r=102,g=153,b=0] value: 8 - java.awt.color[r=153,g=102,b=0] value: 9 - java.awt.color[r=204,g=51,b=0] value: 10 - java.awt.color[r=255,g=0,b=0] based on you've provided, problem seems either in way you're calling function, or in way you're using array returns.
Comments
Post a Comment