In handwritten digit recognition problem using logistic regression, what changes needed to add another class...












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In handwritten digit recognition problem using logistic regression, normal implementation would forcibly classify even a picture of dog or cat as a digit. To eliminate this, what changes are needed to add another class i.e. "Not a Digit" to already existing 10 classes (0 to 9) ?










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    In handwritten digit recognition problem using logistic regression, normal implementation would forcibly classify even a picture of dog or cat as a digit. To eliminate this, what changes are needed to add another class i.e. "Not a Digit" to already existing 10 classes (0 to 9) ?










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      In handwritten digit recognition problem using logistic regression, normal implementation would forcibly classify even a picture of dog or cat as a digit. To eliminate this, what changes are needed to add another class i.e. "Not a Digit" to already existing 10 classes (0 to 9) ?










      share|improve this question









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      In handwritten digit recognition problem using logistic regression, normal implementation would forcibly classify even a picture of dog or cat as a digit. To eliminate this, what changes are needed to add another class i.e. "Not a Digit" to already existing 10 classes (0 to 9) ?







      scikit-learn logistic-regression multiclass-classification image-recognition multilabel-classification






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      asked Nov 16 '18 at 6:20









      Deependra Singh Deependra Singh

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          Logistic regression is normally used to perform binary classification, which answers a yes or no question, e.g.:




          1. Is this an 8 or not?

          2. Will it rain today or not?


          Perhaps I have misunderstood your explanation, but it sounds like you are trying to perform multi-class classification, i.e. to classify an image as one of a certain number of options. So a single image must contain (be classified as) a number from the list: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].



          Usually, to add an extra class to a model that already does this, you would need to adjust the final output of the model to predict a one-hot vector that is simply one element longer!



          In the specific case of the Scikit-Learn LogosticRegression class, it seems as though you don't need to specify anything - the class will automatically use a multinomial model and relevant optimiser as soon as it sees that data is not binary (i.e. a yes-no model as explained above).



          Have a look at this official tutorial, which should a multinomial model trained on a dataset with a target variable that has a total of 20 classes. The number of features (n_classes is equal to 20) is not passed to the model at all, it is inferred.






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            $begingroup$

            Logistic regression is normally used to perform binary classification, which answers a yes or no question, e.g.:




            1. Is this an 8 or not?

            2. Will it rain today or not?


            Perhaps I have misunderstood your explanation, but it sounds like you are trying to perform multi-class classification, i.e. to classify an image as one of a certain number of options. So a single image must contain (be classified as) a number from the list: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].



            Usually, to add an extra class to a model that already does this, you would need to adjust the final output of the model to predict a one-hot vector that is simply one element longer!



            In the specific case of the Scikit-Learn LogosticRegression class, it seems as though you don't need to specify anything - the class will automatically use a multinomial model and relevant optimiser as soon as it sees that data is not binary (i.e. a yes-no model as explained above).



            Have a look at this official tutorial, which should a multinomial model trained on a dataset with a target variable that has a total of 20 classes. The number of features (n_classes is equal to 20) is not passed to the model at all, it is inferred.






            share|improve this answer









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              0












              $begingroup$

              Logistic regression is normally used to perform binary classification, which answers a yes or no question, e.g.:




              1. Is this an 8 or not?

              2. Will it rain today or not?


              Perhaps I have misunderstood your explanation, but it sounds like you are trying to perform multi-class classification, i.e. to classify an image as one of a certain number of options. So a single image must contain (be classified as) a number from the list: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].



              Usually, to add an extra class to a model that already does this, you would need to adjust the final output of the model to predict a one-hot vector that is simply one element longer!



              In the specific case of the Scikit-Learn LogosticRegression class, it seems as though you don't need to specify anything - the class will automatically use a multinomial model and relevant optimiser as soon as it sees that data is not binary (i.e. a yes-no model as explained above).



              Have a look at this official tutorial, which should a multinomial model trained on a dataset with a target variable that has a total of 20 classes. The number of features (n_classes is equal to 20) is not passed to the model at all, it is inferred.






              share|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                Logistic regression is normally used to perform binary classification, which answers a yes or no question, e.g.:




                1. Is this an 8 or not?

                2. Will it rain today or not?


                Perhaps I have misunderstood your explanation, but it sounds like you are trying to perform multi-class classification, i.e. to classify an image as one of a certain number of options. So a single image must contain (be classified as) a number from the list: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].



                Usually, to add an extra class to a model that already does this, you would need to adjust the final output of the model to predict a one-hot vector that is simply one element longer!



                In the specific case of the Scikit-Learn LogosticRegression class, it seems as though you don't need to specify anything - the class will automatically use a multinomial model and relevant optimiser as soon as it sees that data is not binary (i.e. a yes-no model as explained above).



                Have a look at this official tutorial, which should a multinomial model trained on a dataset with a target variable that has a total of 20 classes. The number of features (n_classes is equal to 20) is not passed to the model at all, it is inferred.






                share|improve this answer









                $endgroup$



                Logistic regression is normally used to perform binary classification, which answers a yes or no question, e.g.:




                1. Is this an 8 or not?

                2. Will it rain today or not?


                Perhaps I have misunderstood your explanation, but it sounds like you are trying to perform multi-class classification, i.e. to classify an image as one of a certain number of options. So a single image must contain (be classified as) a number from the list: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].



                Usually, to add an extra class to a model that already does this, you would need to adjust the final output of the model to predict a one-hot vector that is simply one element longer!



                In the specific case of the Scikit-Learn LogosticRegression class, it seems as though you don't need to specify anything - the class will automatically use a multinomial model and relevant optimiser as soon as it sees that data is not binary (i.e. a yes-no model as explained above).



                Have a look at this official tutorial, which should a multinomial model trained on a dataset with a target variable that has a total of 20 classes. The number of features (n_classes is equal to 20) is not passed to the model at all, it is inferred.







                share|improve this answer












                share|improve this answer



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                answered Nov 16 '18 at 8:57









                n1k31t4n1k31t4

                6,5312421




                6,5312421






























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