tf.keras.metrics.TopKCategoricalAccuracy

TensorFlow 1 version View source on GitHub

Computes how often targets are in the top K predictions.

tf.keras.metrics.TopKCategoricalAccuracy(
    k=5, name='top_k_categorical_accuracy', dtype=None
)

Usage:

m = tf.keras.metrics.TopKCategoricalAccuracy(k=1) 
_ = m.update_state([[0, 0, 1], [0, 1, 0]], 
                   [[0.1, 0.9, 0.8], [0.05, 0.95, 0]]) 
m.result().numpy() 
0.5 
m.reset_states() 
_ = m.update_state([[0, 0, 1], [0, 1, 0]], 
                   [[0.1, 0.9, 0.8], [0.05, 0.95, 0]], 
                   sample_weight=[0.7, 0.3]) 
m.result().numpy() 
0.3 

Usage with tf.keras API:

model = tf.keras.Model(inputs, outputs)
model.compile('sgd', metrics=[tf.keras.metrics.TopKCategoricalAccuracy()])

Args:

  • k: (Optional) Number of top elements to look at for computing accuracy. Defaults to 5.
  • name: (Optional) string name of the metric instance.
  • dtype: (Optional) data type of the metric result.

Methods

reset_states

View source

reset_states()

Resets all of the metric state variables.

This function is called between epochs/steps, when a metric is evaluated during training.

result

View source

result()

Computes and returns the metric value tensor.

Result computation is an idempotent operation that simply calculates the metric value using the state variables.

update_state

View source

update_state(
    y_true, y_pred, sample_weight=None
)

Accumulates metric statistics.

y_true and y_pred should have the same shape.

Args:

  • y_true: Ground truth values. shape = [batch_size, d0, .. dN].
  • y_pred: The predicted values. shape = [batch_size, d0, .. dN].
  • sample_weight: Optional sample_weight acts as a coefficient for the metric. If a scalar is provided, then the metric is simply scaled by the given value. If sample_weight is a tensor of size [batch_size], then the metric for each sample of the batch is rescaled by the corresponding element in the sample_weight vector. If the shape of sample_weight is [batch_size, d0, .. dN-1] (or can be broadcasted to this shape), then each metric element of y_pred is scaled by the corresponding value of sample_weight. (Note on dN-1: all metric functions reduce by 1 dimension, usually the last axis (-1)).

Returns:

Update op.