diceIndexOf function

double diceIndexOf(String source, String target, { int ngram = 1, bool ignoreCase = false, bool ignoreWhitespace = false, bool ignoreNumbers = false, bool alphaNumericOnly = false, })

Finds the Sørensen–Dice coefficient of two strings.

Parameters

• source is the variant string
• target is the prototype string
• if ignoreCase is true, the character case shall be ignored.
• if ignoreWhitespace is true, space, tab, newlines etc whitespace characters will be ignored.
• if ignoreNumbers is true, numbers will be ignored.
• if alphaNumericOnly is true, only letters and digits will be matched.
• ngram is the size a single item group. If n = 1, each individual items are considered separately. If n = 2, two consecutive items are grouped together and treated as one.

TIPS: You can pass both ignoreNumbers and alphaNumericOnly to true to ignore everything else except letters.

Details

Sørensen–Dice coefficient is a metric used to measure similarity between two samples. This is known by several other names:

• Sørensen index
• Dice's coefficient
• Dice similarity coefficient (DSC)

Tversky index is a generalization of Dice index when alpha = 0.5, and beta = 0.5

See Also: tverskyIndex, diceIndex

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Complexity: Time O(n log n) | Space O(n)

Implementation

double diceIndexOf(
  String source,
  String target, {
  int ngram = 1,
  bool ignoreCase = false,
  bool ignoreWhitespace = false,
  bool ignoreNumbers = false,
  bool alphaNumericOnly = false,
}) {
  return tverskyIndexOf(
    source,
    target,
    alpha: 0.5,
    beta: 0.5,
    ngram: ngram,
    ignoreCase: ignoreCase,
    ignoreWhitespace: ignoreWhitespace,
    ignoreNumbers: ignoreNumbers,
    alphaNumericOnly: alphaNumericOnly,
  );
}