$p['temp'], $chart_points), fn($v) => $v !== null));
$hums = array_values(array_filter(array_map(fn($p) => $p['hum'], $chart_points), fn($v) => $v !== null));
// 온도 축 범위 (여유 패딩)
$t_min = !empty($temps) ? min($temps) : 0;
$t_max = !empty($temps) ? max($temps) : 1;
if ($t_min === $t_max) { $t_min -= 1; $t_max += 1; }
$t_pad = ($t_max - $t_min) * 0.1;
$t_min -= $t_pad; $t_max += $t_pad;
// 습도 축 범위
$h_min = !empty($hums) ? min($hums) : 0;
$h_max = !empty($hums) ? max($hums) : 1;
if ($h_min === $h_max) { $h_min -= 1; $h_max += 1; }
$h_pad = ($h_max - $h_min) * 0.1;
$h_min -= $h_pad; $h_max += $h_pad;
$x_at = function (int $i) use ($pad_l, $plot_w, $n): float {
if ($n <= 1) { return $pad_l; }
return $pad_l + ($plot_w * $i / ($n - 1));
};
$y_temp = function (?float $v) use ($pad_t, $plot_h, $t_min, $t_max): ?float {
if ($v === null) { return null; }
$r = ($t_max - $t_min) ?: 1;
return $pad_t + $plot_h * (1 - (($v - $t_min) / $r));
};
$y_hum = function (?float $v) use ($pad_t, $plot_h, $h_min, $h_max): ?float {
if ($v === null) { return null; }
$r = ($h_max - $h_min) ?: 1;
return $pad_t + $plot_h * (1 - (($v - $h_min) / $r));
};
// 결측(null)은 구간을 끊어 polyline 들을 만든다
$build_segments = function (string $key, callable $y_fn) use ($chart_points, $x_at): array {
$segments = [];
$current = [];
foreach ($chart_points as $i => $p) {
$val = $p[$key];
if ($val === null) {
if (count($current) >= 2) { $segments[] = $current; }
$current = [];
continue;
}
$current[] = sprintf('%.1f,%.1f', $x_at($i), $y_fn((float)$val));
}
if (count($current) >= 2) { $segments[] = $current; }
return $segments;
};
$temp_segments = $build_segments('temp', $y_temp);
$hum_segments = $build_segments('hum', $y_hum);
$fmt = fn($v) => rtrim(rtrim(number_format($v, 1, '.', ''), '0'), '.');
?>
추이를 표시할 측정 데이터가 충분하지 않습니다 (2개 이상 필요).