php mysql histogram

<?php

// Connect to MySQL
$conn = mysqli_connect('host', 'username', 'password', 'database');

// Define the number of bins
$bins = 10;

// Select the minimum and maximum values from the column
$result = mysqli_query($conn, "SELECT MIN(col) AS min, MAX(col) AS max FROM table");
$row = mysqli_fetch_assoc($result);
$min = $row['min'];
$max = $row['max'];

// Calculate the bin size
$bin_size = ($max - $min) / $bins;

// Initialize an array to hold the bin frequencies
$bin_freqs = array_fill(0, $bins, 0);

// Select the values from the column and assign them to bins
$result = mysqli_query($conn, "SELECT col FROM table");
while ($row = mysqli_fetch_assoc($result)) {
    $col = $row['col'];
    $bin = floor(($col - $min) / $bin_size);
    $bin_freqs[$bin]++;
}

// Print the histogram
for ($i = 0; $i < $bins; $i++) {
    $bin_left = $min + $i * $bin_size;
    $bin_right = $bin_left + $bin_size;
    echo "$bin_left - $bin_right: $bin_freqs[$i]\n";
}

// Close the connection
mysqli_close($conn);