A column-vector y was passed when a 1d array was expected

Question

I need to fit RandomForestRegressor from sklearn ensemble  forest   ensemble RandomForestRegressor   RF tuned parameters  model   forest fit train fold  train y  yhat   model predict test fold   This code always worked until I made some preprocessing of data  train y   The error message says   DataConversionWarning  A column-vector y was passed when a 1d array was expected  Please change the shape of y to  n samples    for example using ravel    model   forest fit train fold  train y   Previously train y was a Series  now it s numpy array  it is a column-vector   If I apply train y ravel    then it becomes a row vector and no error message appears  through the prediction step takes very long time  actually it never finishes      In the docs of RandomForestRegressor I found that train y should be defined as y   array-like  shape    n samples  or  n samples  n outputs  Any idea how to solve this issue

User · Answer

use below code   model   forest fit train fold  train y ravel      if you are still getting slap by error as identical as below    Unknown label type   r    y   use this code   y   train y ravel   train y   np array y  astype int  model   forest fit train fold  train y

User · Answer

Change this line    model   forest fit train fold  train y    to   model   forest fit train fold  train y values ravel      Edit    values will give the values in an array   shape   n 1    ravel will convert that array shape to  n

User · Answer

With neuraxle  you can easily solve this     p   Pipeline        expected outputs shape   n  1     OutputTransformerWrapper NumpyRavel           expected outputs shape   n       RandomForestRegressor   RF tuned parameters      p  outputs   p fit transform data inputs  expected outputs    Neuraxle is a sklearn-like framework for hyperparameter tuning and AutoML in deep learning projects

User · Answer

Another way of doing this is to use ravel  model   forest fit train fold  train y values reshape -1

User · Answer

I also encountered this situation when I was trying to train a KNN classifier  but it seems that the warning was gone after I changed  knn fit X train y train  to knn fit X train  np ravel y train order  C     Ahead of this line I used import numpy as np

User · Answer

I had the same problem  The problem was that the labels were in a column format while it expected it in a row  use np ravel    knn score training set  np ravel training labels     Hope this solves it

User · Answer

format train y    for n in train y      format train y append n 0

User · Answer

Y   y values   0   Y - formated train y  y - train y

[python] A column-vector y was passed when a 1d array was expected

Examples related to python

Examples related to pandas

Examples related to numpy

Examples related to scikit-learn