PhpSpreadsheet/tests/data/Calculation/Financial/ISPMT.php

<?php

// rate, per, nper, pv, result

return [
    [
        -64814.814812222001,
        0.0083333333329999992,
        1,
        36,
        8000000,
    ],
    [
        -533333.33333333,
        0.10000000000000001,
        1,
        3,
        8000000,
    ],
    [
        -204.86111112750001,
        0.0041666666669999998,
        1,
        60,
        50000,
    ],
    [
        -201.38888890499999,
        0.0041666666669999998,
        2,
        60,
        50000,
    ],
];