Label

use Risan\Sentiment\Label;

enum Label: string is the verdict of an analysis, available as Result::$label.

Cases

How the label is chosen

The label comes from the compound score and the analyzer’s threshold:

• Label::Positive when compound > 0 and compound >= threshold;
• Label::Negative when compound < 0 and compound <= -threshold;
• Label::Neutral otherwise.

With the default threshold of 0.05, a compound of 0.05 is positive and 0.049 is neutral. A compound of exactly zero is always neutral.

Usage

Because it is a backed enum, Label works with everything PHP offers for enums:

use Risan\Sentiment\Label;
use Risan\Sentiment\Sentiment;

$result = Sentiment::analyze('This package is awesome!');

$result->label === Label::Positive; // true
$result->label->value;              // 'positive'
$result->label->name;               // 'Positive'

Label::from('negative');            // Label::Negative
Label::tryFrom('mixed');            // null
Label::cases();                     // [Positive, Negative, Neutral]

$emoji = match ($result->label) {
    Label::Positive => '🙂',
    Label::Negative => '🙁',
    Label::Neutral => '😐',
};

Label::from() throws a ValueError for an unknown value. Use tryFrom() when the value may be invalid.