Transform a collection of text samples to a vector of token counts.
### Constructor Parameters
* $tokenizer (Tokenizer) - tokenizer object (see below)
* $minDF (float) - ignore tokens that have a samples frequency strictly lower than the given threshold. This value is also called cut-off in the literature. (default 0)
```
use Phpml\FeatureExtraction\TokenCountVectorizer;
use Phpml\Tokenization\WhitespaceTokenizer;
$vectorizer = new TokenCountVectorizer(new WhitespaceTokenizer());
* NGramTokenizer - continuous sequence of characters of the specified length. They are useful for querying languages that don’t use spaces or that have long compound words, like German.
**NGramTokenizer**
The NGramTokenizer tokenizer accepts the following parameters:
`$minGram` - minimum length of characters in a gram. Defaults to 1.
`$maxGram` - maximum length of characters in a gram. Defaults to 2.