sklearn log_loss different number of classes












3















I'm using log_loss with sklearn



from sklearn.metrics import log_loss
print log_loss(true, pred,normalize=False)


and i have following error:



ValueError: y_true and y_pred have different number of classes 38, 2


It is really strange to me since, the arrays look valid:



print pred.shape
print np.unique(pred)
print np.unique(pred).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38

print true.shape
print np.unique(true)
print np.unique(true).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38


What is wrong with the log_loss? Why it throws the error?



Sample data:



pred: array([ 0,  1,  2, ...,  3, 12, 16], dtype=int64)
true: array([ 0, 1, 2, ..., 3, 12, 16])









share|improve this question

























  • Can you post some data for pred and true? It looks like your labels are being passed incorrectly.

    – ryanmc
    Nov 9 '15 at 19:25











  • Added to the original post

    – Ablomis
    Nov 9 '15 at 19:28








  • 2





    Log loss is to be used to assess the accuracy of probabilities - it is expecting an array of probabilities associated with every possible label (you are passing only label). I believe your pred variable should be an array of n-arrays, where n is the number of labels.

    – ryanmc
    Nov 9 '15 at 20:03


















3















I'm using log_loss with sklearn



from sklearn.metrics import log_loss
print log_loss(true, pred,normalize=False)


and i have following error:



ValueError: y_true and y_pred have different number of classes 38, 2


It is really strange to me since, the arrays look valid:



print pred.shape
print np.unique(pred)
print np.unique(pred).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38

print true.shape
print np.unique(true)
print np.unique(true).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38


What is wrong with the log_loss? Why it throws the error?



Sample data:



pred: array([ 0,  1,  2, ...,  3, 12, 16], dtype=int64)
true: array([ 0, 1, 2, ..., 3, 12, 16])









share|improve this question

























  • Can you post some data for pred and true? It looks like your labels are being passed incorrectly.

    – ryanmc
    Nov 9 '15 at 19:25











  • Added to the original post

    – Ablomis
    Nov 9 '15 at 19:28








  • 2





    Log loss is to be used to assess the accuracy of probabilities - it is expecting an array of probabilities associated with every possible label (you are passing only label). I believe your pred variable should be an array of n-arrays, where n is the number of labels.

    – ryanmc
    Nov 9 '15 at 20:03
















3












3








3


1






I'm using log_loss with sklearn



from sklearn.metrics import log_loss
print log_loss(true, pred,normalize=False)


and i have following error:



ValueError: y_true and y_pred have different number of classes 38, 2


It is really strange to me since, the arrays look valid:



print pred.shape
print np.unique(pred)
print np.unique(pred).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38

print true.shape
print np.unique(true)
print np.unique(true).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38


What is wrong with the log_loss? Why it throws the error?



Sample data:



pred: array([ 0,  1,  2, ...,  3, 12, 16], dtype=int64)
true: array([ 0, 1, 2, ..., 3, 12, 16])









share|improve this question
















I'm using log_loss with sklearn



from sklearn.metrics import log_loss
print log_loss(true, pred,normalize=False)


and i have following error:



ValueError: y_true and y_pred have different number of classes 38, 2


It is really strange to me since, the arrays look valid:



print pred.shape
print np.unique(pred)
print np.unique(pred).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38

print true.shape
print np.unique(true)
print np.unique(true).size
(19191L,)
[ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37]
38


What is wrong with the log_loss? Why it throws the error?



Sample data:



pred: array([ 0,  1,  2, ...,  3, 12, 16], dtype=int64)
true: array([ 0, 1, 2, ..., 3, 12, 16])






python scikit-learn






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 9 '15 at 19:29







Ablomis

















asked Nov 9 '15 at 18:52









AblomisAblomis

3515




3515













  • Can you post some data for pred and true? It looks like your labels are being passed incorrectly.

    – ryanmc
    Nov 9 '15 at 19:25











  • Added to the original post

    – Ablomis
    Nov 9 '15 at 19:28








  • 2





    Log loss is to be used to assess the accuracy of probabilities - it is expecting an array of probabilities associated with every possible label (you are passing only label). I believe your pred variable should be an array of n-arrays, where n is the number of labels.

    – ryanmc
    Nov 9 '15 at 20:03





















  • Can you post some data for pred and true? It looks like your labels are being passed incorrectly.

    – ryanmc
    Nov 9 '15 at 19:25











  • Added to the original post

    – Ablomis
    Nov 9 '15 at 19:28








  • 2





    Log loss is to be used to assess the accuracy of probabilities - it is expecting an array of probabilities associated with every possible label (you are passing only label). I believe your pred variable should be an array of n-arrays, where n is the number of labels.

    – ryanmc
    Nov 9 '15 at 20:03



















Can you post some data for pred and true? It looks like your labels are being passed incorrectly.

– ryanmc
Nov 9 '15 at 19:25





Can you post some data for pred and true? It looks like your labels are being passed incorrectly.

– ryanmc
Nov 9 '15 at 19:25













Added to the original post

– Ablomis
Nov 9 '15 at 19:28







Added to the original post

– Ablomis
Nov 9 '15 at 19:28






2




2





Log loss is to be used to assess the accuracy of probabilities - it is expecting an array of probabilities associated with every possible label (you are passing only label). I believe your pred variable should be an array of n-arrays, where n is the number of labels.

– ryanmc
Nov 9 '15 at 20:03







Log loss is to be used to assess the accuracy of probabilities - it is expecting an array of probabilities associated with every possible label (you are passing only label). I believe your pred variable should be an array of n-arrays, where n is the number of labels.

– ryanmc
Nov 9 '15 at 20:03














3 Answers
3






active

oldest

votes


















6














It's simple, you are using the prediction and not the probability of your prediction. Your pred variable contains [ 1 2 1 3 .... ] but to use log_loss it should contain something like [[ 0.1, 0.8, 0.1] [ 0.0, 0.79 , 0.21] .... ]. to obtain these probabilities use the function predict_proba:



pred = model.predict_proba(x_test)
eval = log_loss(y_true,pred)





share|improve this answer

































    1














    Inside the log_loss method, true array is fit and transformed by a LabelBinarizer which changes its dimensions. So, the check that true and pred have similar dimensions doesn't mean that log_loss method will work because true's dimensions change. If you just have binary classes, I suggest you use this log_loss cost function else for multiple classes, this method doesn't work.






    share|improve this answer































      1














      From the log_loss documentation:




      y_pred : array-like of float, shape = (n_samples, n_classes) or (n_samples,)



      Predicted probabilities, as returned by a classifier’s predict_proba method. If y_pred.shape = (n_samples,) the probabilities provided are assumed to be that of the positive class. The labels in y_pred are assumed to be ordered alphabetically, as done by preprocessing.LabelBinarizer.




      You need to pass probabilities not the prediction labels.






      share|improve this answer























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        3 Answers
        3






        active

        oldest

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        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        6














        It's simple, you are using the prediction and not the probability of your prediction. Your pred variable contains [ 1 2 1 3 .... ] but to use log_loss it should contain something like [[ 0.1, 0.8, 0.1] [ 0.0, 0.79 , 0.21] .... ]. to obtain these probabilities use the function predict_proba:



        pred = model.predict_proba(x_test)
        eval = log_loss(y_true,pred)





        share|improve this answer






























          6














          It's simple, you are using the prediction and not the probability of your prediction. Your pred variable contains [ 1 2 1 3 .... ] but to use log_loss it should contain something like [[ 0.1, 0.8, 0.1] [ 0.0, 0.79 , 0.21] .... ]. to obtain these probabilities use the function predict_proba:



          pred = model.predict_proba(x_test)
          eval = log_loss(y_true,pred)





          share|improve this answer




























            6












            6








            6







            It's simple, you are using the prediction and not the probability of your prediction. Your pred variable contains [ 1 2 1 3 .... ] but to use log_loss it should contain something like [[ 0.1, 0.8, 0.1] [ 0.0, 0.79 , 0.21] .... ]. to obtain these probabilities use the function predict_proba:



            pred = model.predict_proba(x_test)
            eval = log_loss(y_true,pred)





            share|improve this answer















            It's simple, you are using the prediction and not the probability of your prediction. Your pred variable contains [ 1 2 1 3 .... ] but to use log_loss it should contain something like [[ 0.1, 0.8, 0.1] [ 0.0, 0.79 , 0.21] .... ]. to obtain these probabilities use the function predict_proba:



            pred = model.predict_proba(x_test)
            eval = log_loss(y_true,pred)






            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited Nov 21 '18 at 9:44

























            answered Mar 22 '17 at 13:37









            deltasciencedeltascience

            1,49222652




            1,49222652

























                1














                Inside the log_loss method, true array is fit and transformed by a LabelBinarizer which changes its dimensions. So, the check that true and pred have similar dimensions doesn't mean that log_loss method will work because true's dimensions change. If you just have binary classes, I suggest you use this log_loss cost function else for multiple classes, this method doesn't work.






                share|improve this answer




























                  1














                  Inside the log_loss method, true array is fit and transformed by a LabelBinarizer which changes its dimensions. So, the check that true and pred have similar dimensions doesn't mean that log_loss method will work because true's dimensions change. If you just have binary classes, I suggest you use this log_loss cost function else for multiple classes, this method doesn't work.






                  share|improve this answer


























                    1












                    1








                    1







                    Inside the log_loss method, true array is fit and transformed by a LabelBinarizer which changes its dimensions. So, the check that true and pred have similar dimensions doesn't mean that log_loss method will work because true's dimensions change. If you just have binary classes, I suggest you use this log_loss cost function else for multiple classes, this method doesn't work.






                    share|improve this answer













                    Inside the log_loss method, true array is fit and transformed by a LabelBinarizer which changes its dimensions. So, the check that true and pred have similar dimensions doesn't mean that log_loss method will work because true's dimensions change. If you just have binary classes, I suggest you use this log_loss cost function else for multiple classes, this method doesn't work.







                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered Jun 29 '16 at 8:01









                    Hima VarshaHima Varsha

                    226111




                    226111























                        1














                        From the log_loss documentation:




                        y_pred : array-like of float, shape = (n_samples, n_classes) or (n_samples,)



                        Predicted probabilities, as returned by a classifier’s predict_proba method. If y_pred.shape = (n_samples,) the probabilities provided are assumed to be that of the positive class. The labels in y_pred are assumed to be ordered alphabetically, as done by preprocessing.LabelBinarizer.




                        You need to pass probabilities not the prediction labels.






                        share|improve this answer




























                          1














                          From the log_loss documentation:




                          y_pred : array-like of float, shape = (n_samples, n_classes) or (n_samples,)



                          Predicted probabilities, as returned by a classifier’s predict_proba method. If y_pred.shape = (n_samples,) the probabilities provided are assumed to be that of the positive class. The labels in y_pred are assumed to be ordered alphabetically, as done by preprocessing.LabelBinarizer.




                          You need to pass probabilities not the prediction labels.






                          share|improve this answer


























                            1












                            1








                            1







                            From the log_loss documentation:




                            y_pred : array-like of float, shape = (n_samples, n_classes) or (n_samples,)



                            Predicted probabilities, as returned by a classifier’s predict_proba method. If y_pred.shape = (n_samples,) the probabilities provided are assumed to be that of the positive class. The labels in y_pred are assumed to be ordered alphabetically, as done by preprocessing.LabelBinarizer.




                            You need to pass probabilities not the prediction labels.






                            share|improve this answer













                            From the log_loss documentation:




                            y_pred : array-like of float, shape = (n_samples, n_classes) or (n_samples,)



                            Predicted probabilities, as returned by a classifier’s predict_proba method. If y_pred.shape = (n_samples,) the probabilities provided are assumed to be that of the positive class. The labels in y_pred are assumed to be ordered alphabetically, as done by preprocessing.LabelBinarizer.




                            You need to pass probabilities not the prediction labels.







                            share|improve this answer












                            share|improve this answer



                            share|improve this answer










                            answered Mar 22 '17 at 7:37









                            ug2409ug2409

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