R-package cv

[brsoyanvn]

Implemented catboost.cv function in R-package.

I hereby agree to the terms of the CLA available at: https://yandex.ru/legal/cla/?lang=en.

[nikitxskv]

Several comments.

[brsoyanvn]

@nikitxskv I fixed the issues you pointed me to.

[nikitxskv]

@arcadia-devtools Ship it!

[annaveronika]

We are currently planning our next release. For now the planned date is Friday. It would be super nice to have this pr in. Please do the changes asap.

[arcadia-devtools]

@nikitxskv, internal review request created: 645875

[annaveronika]

There is a build error

$(SOURCE_ROOT)/catboost/R-package/src/catboostr.cpp:439:5: error: no matching function for call to 'CrossValidate'
CrossValidate(
^~~~~~~~~~~~~
$(SOURCE_ROOT)/catboost/libs/train_lib/cross_validation.h:131:6: note: candidate function not viable: no known conversion from 'NCB::TDataProvider' (aka 'TDataProviderTemplateNCB::TObjectsDataProvider') to 'NCB::TDataProviderPtr' (aka 'TIntrusivePtr<TDataProviderTemplateNCB::TObjectsDataProvider >') for 4th argument
void CrossValidate(
^
1 error generated.

[annaveronika]

@brsoyanvn There is a build error, could you fix it? Do you see it when building?

[Evgueni-Petrov-aka-espetrov]

Hopefully, the error will go away if dereferencing is removed...

[brsoyanvn]

@annaveronika There is no any build error now

[annaveronika]

@brsoyanvn There are conflicts, could you resolve them?

[annaveronika]

@brsoyanvn Do you plan to finish this?

[brsoyanvn]

@annaveronika sorry for a delay, I was busy with other issues. I resolved the conflicts

[annaveronika]

@arcadia-devtools Ship it!

[arcadia-devtools]

@nikitxskv, internal review request created: 675767