用php 将不连续数据转为等间距连续数据

Question

有数据集如下:每行一组，可看成是（X,Y）用逗号分隔。 要求用php 写一个方法，将X值等间距，并得出对应Y值。
0.0,44.470,
0.56,44.47,
1.08,44.46,
12.44,44.37,
14.05,44.50,
14.53,0.00,
15.19,0.00,
18.95,44.11,
23.64,43.50,
29.27,43.45,
30.81,43.28,

要求结果如下:
0, 44.470
1,Y
2,Y
3,Y
4,Y
中间省略
30,Y
X是等间距，Y值需要根据前后值生成平均数，呈线性关系。个别明显有误的点需要清除。 例如（14.53,0.00）。

Answer 1

<?php

function interpolateData($data) {
  $result = array();
  $lastValidY = null;
  
  foreach ($data as $index => $entry) {
    $values = explode(',', $entry);
    $x = intval($values[0]);
    $y = floatval($values[1]);
    
    if ($index === 0) {
      $result[$x] = $y;
    } else {
      $prevX = $lastX;
      $prevY = $lastValidY !== null ? $lastValidY : $lastY;
      
      $diffX = $x - $prevX;
      $diffY = $y - $prevY;
      
      if ($diffX > 1) {
        $stepY = $diffY / $diffX;
        
        for ($i = 1; $i < $diffX; $i++) {
          $interpolatedX = $prevX + $i;
          $interpolatedY = $prevY + ($stepY * $i);
          
          $result[$interpolatedX] = $interpolatedY;
        }
      }
      
      $result[$x] = $y;
      
      if ($y !== 0) {
        $lastValidY = $y;
      }
    }
    
    $lastX = $x;
    $lastY = $y;
  }
  
  return $result;
}

// 使用示例
$data = [
  "0.0,44.470",
  "0.56,44.47",
  "1.08,44.46",
  "12.44,44.37",
  "14.05,44.50",
  "14.53,0.00",
  "15.19,0.00",
  "18.95,44.11",
  "23.64,43.50",
  "29.27,43.45",
  "30.81,43.28"
];

$interpolatedData = interpolateData($data);

foreach ($interpolatedData as $x => $y) {
  echo "{$x}, " . ($y !== 0 ? $y : 'Y') . PHP_EOL;
}

?>