If an utterance x only contains language independent tokens, its code-mixing is zero; for other utterances, the level of mixing depends on the fraction of language dependent tokens that belong to the matrix language (the most frequent language in the utterance) and on N , the number of tokens in x except the language independent ones (i.e., all tokens that belong to any language This initial measure has several short-comings.
it does not reflect what fraction of a corpus' utterances contain code-switching, nor take into account the number 1 Note that the formula in Equation 1 differs from, but is equivalent to, the one given in Gambäck and Das (2014).