| activation | | default: "relu" |
| alpha | Strength of the L2 regularization term. The L2 regularization term
is divided by the sample size when added to the loss | default: 0.0001 |
| batch_size | Size of minibatches for stochastic optimizers
If the solver is 'lbfgs', the classifier will not use minibatch
When set to "auto", `batch_size=min(200, n_samples)`
learning_rate : {'constant', 'invscaling', 'adaptive'}, default='constant'
Learning rate schedule for weight updates
- 'constant' is a constant learning rate given by
'learning_rate_init'
- 'invscaling' gradually decreases the learning rate at each
time step 't' using an inverse scaling exponent of 'power_t'
effective_learning_rate = learning_rate_init / pow(t, power_t)
- 'adaptive' keeps the learning rate constant to
'learning_rate_init' as long as training loss keeps decreasing
Each time two consecutive epochs fail to decrease training loss by at
least tol, or fail to increase validation score by at least tol if
'early_stopping' is on, the current learning rate is divided by 5
Only used when ``solver='sgd'`` | default: "auto" |
| beta_1 | Exponential decay rate for estimates of first moment vector in adam,
should be in [0, 1). Only used when solver='adam' | default: 0.9 |
| beta_2 | Exponential decay rate for estimates of second moment vector in adam,
should be in [0, 1). Only used when solver='adam' | default: 0.999 |
| early_stopping | Whether to use early stopping to terminate training when validation
score is not improving. If set to true, it will automatically set
aside 10% of training data as validation and terminate training when
validation score is not improving by at least tol for
``n_iter_no_change`` consecutive epochs. The split is stratified,
except in a multilabel setting
If early stopping is False, then the training stops when the training
loss does not improve by more than tol for n_iter_no_change consecutive
passes over the training set
Only effective when solver='sgd' or 'adam' | default: false |
| epsilon | Value for numerical stability in adam. Only used when solver='adam' | default: 1e-08 |
| hidden_layer_sizes | The ith element represents the number of neurons in the ith
hidden layer
activation : {'identity', 'logistic', 'tanh', 'relu'}, default='relu'
Activation function for the hidden layer
- 'identity', no-op activation, useful to implement linear bottleneck,
returns f(x) = x
- 'logistic', the logistic sigmoid function,
returns f(x) = 1 / (1 + exp(-x))
- 'tanh', the hyperbolic tan function,
returns f(x) = tanh(x)
- 'relu', the rectified linear unit function,
returns f(x) = max(0, x)
solver : {'lbfgs', 'sgd', 'adam'}, default='adam'
The solver for weight optimization
- 'lbfgs' is an optimizer in the family of quasi-Newton methods
- 'sgd' refers to stochastic gradient descent
- 'adam' refers to a stochastic gradient-based optimizer proposed
by Kingma, Diederik, and Jimmy Ba
Note: The default solver 'adam' works pretty well on relatively
large datasets (with thousands of training samples or more) in terms of
both training t... | default: [100] |
| learning_rate | | default: "constant" |
| learning_rate_init | The initial learning rate used. It controls the step-size
in updating the weights. Only used when solver='sgd' or 'adam' | default: 0.001 |
| max_fun | Only used when solver='lbfgs'. Maximum number of loss function calls
The solver iterates until convergence (determined by 'tol'), number
of iterations reaches max_iter, or this number of loss function calls
Note that number of loss function calls will be greater than or equal
to the number of iterations for the `MLPClassifier`
.. versionadded:: 0.22 | default: 15000 |
| max_iter | Maximum number of iterations. The solver iterates until convergence
(determined by 'tol') or this number of iterations. For stochastic
solvers ('sgd', 'adam'), note that this determines the number of epochs
(how many times each data point will be used), not the number of
gradient steps | default: 200 |
| momentum | Momentum for gradient descent update. Should be between 0 and 1. Only
used when solver='sgd' | default: 0.9 |
| n_iter_no_change | Maximum number of epochs to not meet ``tol`` improvement
Only effective when solver='sgd' or 'adam'
.. versionadded:: 0.20 | default: 10 |
| nesterovs_momentum | Whether to use Nesterov's momentum. Only used when solver='sgd' and
momentum > 0 | default: true |
| power_t | The exponent for inverse scaling learning rate
It is used in updating effective learning rate when the learning_rate
is set to 'invscaling'. Only used when solver='sgd' | default: 0.5 |
| random_state | Determines random number generation for weights and bias
initialization, train-test split if early stopping is used, and batch
sampling when solver='sgd' or 'adam'
Pass an int for reproducible results across multiple function calls
See :term:`Glossary ` | default: null |
| shuffle | Whether to shuffle samples in each iteration. Only used when
solver='sgd' or 'adam' | default: true |
| solver | | default: "adam" |
| tol | Tolerance for the optimization. When the loss or score is not improving
by at least ``tol`` for ``n_iter_no_change`` consecutive iterations,
unless ``learning_rate`` is set to 'adaptive', convergence is
considered to be reached and training stops | default: 0.0001 |
| validation_fraction | The proportion of training data to set aside as validation set for
early stopping. Must be between 0 and 1
Only used if early_stopping is True | default: 0.1 |
| verbose | Whether to print progress messages to stdout | default: false |
| warm_start | When set to True, reuse the solution of the previous
call to fit as initialization, otherwise, just erase the
previous solution. See :term:`the Glossary ` | default: false |