PHP 7.0.6 Released

    sin

    (PHP 4, PHP 5, PHP 7)

    sin — Sine

    Description

    float sin ( float $arg )

    sin() returns the sine of the arg parameter. The arg parameter is in radians.

    Parameters

    arg

    A value in radians

    Return Values

    The sine of arg

    Examples

    Example #1 sin() example

    <?php

    // Precision depends on your precision directive
    echo sin(deg2rad(60));  //  0.866025403 ...
    echo sin(60);           // -0.304810621 ...

    ?>

    See Also

    User Contributed Notes

    gerjoo at gmail dot com
    6 years ago
    You can use SIN & COS to create/draw circles.

    Please beware that the circle's center is also your base point (0,0). So without specifying an offset, some coordinates will be negative.

    <?php

    $circleRadius     = 70;
    $offsetX      = 100;
    $offsetY      = 100;

    for(    $i = 0; $i <= 360; ++$i) {
            $x = round(cos($i * M_PI / 180) * $circleRadius);
            $y = round(sin($i * M_PI / 180) * $circleRadius);
       
            // Draw some pixel, or do something else here.
            imagesetpixel($GDimage, $x + $offsetX, $y + $offsetY, $GDcolor);
    }

    ?>
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