Passing 1D arrays to check_array, without setting `ensure_2d` to false now
raises a deprecation warning before reshaping it. This will later throw an
error.
All Scaler classes also throw warnings when 1D arrays are passed.
All unit tests/doctests are modified to ensure that no 1D arrays are passed,
except in explicit 1D array tests where the warnings have been silenced.
Additional tests are also included which check for different 1D array cases.
2D array tests with one samples and one features are also added and where
they failed, `check_array` call has been modified to give a more useful error
message
MAINT Remove sequence of sequence support from datasets
MAINT Remove return_indicator param
MAINT Remove multilabel-seq test in OVR
MAINT Remove multilable-seq test in check_cv
MAINT Remove multilabel seq test in label_binarizer
TST type_of_target returns "unknown" for multilabel-sequence types
TST _check_targets should raise a ValueError
DOC show multilabel indicator as an example; remove return_indicator param
DOC use consistent lower case y for target
Forests now use the threading backend that has such a low overhead
that batching tasks together does not bring any measurable
performance benefit.
This removes the boilerplate to simplify the code and make it
easier to understand and maintain.
Furthermore, batching will soon be implemented in joblib. So even for
models that use the multiprocessing backend, manually batching tasks
will be useless at some point.
OOB scores of RandomForestClassifier are incorrectly calculated
because of confusion between predicted labels and indices of a target.
For example, when you label the `digits` dataset from 1 or greater
number but 0, OOB score becomes nearly zero.
This patch will fix this error, and a test is added in order to avoid
regression.