数値を色で表現する Ruby メソッド
class Float # -1〜1 の数値を #rrggbb 形式の色で表現する def torgb s = 0.75 # 彩度 v = 1.00 # 明るさ h = (self <= -1) ? 359.9999 : (self > 1) ? 0 : 180.0 - self * 180.0 # 色相 i = (h / 60).floor f = (h / 60) - i m = v * (1 - s) n = v * (1 - s * f) k = v * (1 - s * (1 - f)) case i when 0 then r = v; g = k; b = m; when 1 then r = n; g = v; b = m; when 2 then r = m; g = v; b = k; when 3 then r = m; g = n; b = v; when 4 then r = k; g = m; b = v; when 5 then r = v; g = m; b = n; end sprintf("#%02x%02x%02x", r * 255, g * 255, b * 255) end end