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# System prepended metadata

title: Untitled

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dimentionality reduction: we usually want to reduce in txtanlss.

how to choose raw and columns determines evrthng.

whether these words discriminate texts or just noises: if latter, remove them

most study unigrams

1. get texts and import to R
2. convert them into a corpus
3. get info and analys

types: unique words

```R
corpus_subset(name,key)

tokens(name,function)
