Correct the docstring.
Merge pull request #56 from zuoshifan/zuo/blockla

Correct the docstring.
Merge pull request #55 from zuoshifan/zuo/psestimation

Zuo/psestimation
Remove redundant code.

These code exists below.
Fixed #51 attribute error self.bands.

And fixed a typo.
Comment out a redundant sentence.
Fixed index bug of clarray.