metric_binary_accuracy {keras} | R Documentation

## Model performance metrics

### Description

Model performance metrics

### Usage

    metric_binary_accuracy(y_true, y_pred)

    metric_binary_crossentropy(y_true, y_pred)

    metric_categorical_accuracy(y_true, y_pred)

    metric_categorical_crossentropy(y_true, y_pred)

    metric_cosine_proximity(y_true, y_pred)

    metric_hinge(y_true, y_pred)

    metric_kullback_leibler_divergence(y_true, y_pred)

    metric_mean_absolute_error(y_true, y_pred)

    metric_mean_absolute_percentage_error(y_true, y_pred)

    metric_mean_squared_error(y_true, y_pred)

    metric_mean_squared_logarithmic_error(y_true, y_pred)

    metric_poisson(y_true, y_pred)

    metric_sparse_categorical_crossentropy(y_true, y_pred)

    metric_squared_hinge(y_true, y_pred)

    metric_top_k_categorical_accuracy(y_true, y_pred, k = 5)

    metric_sparse_top_k_categorical_accuracy(y_true, y_pred, k = 5)

    custom_metric(name, metric_fn)

### Arguments

`y_true` | True labels (tensor)
`y_pred` | Predictions (tensor of the same shape as y_true).
`k` | An integer, number of top elements to consider.
`name` | Name of custom metric
`metric_fn` | Custom metric function

### Custom Metrics

You can provide an arbitrary R function as a custom metric. Note that the `y_true` and `y_pred` parameters are tensors, so computations on them should use backend tensor functions.

Use the `custom_metric()` function to define a custom metric. Note that a name ('mean_pred') is provided for the custom metric function: this name is used within training progress output. See below for an example.

If you want to save and load a model with custom metrics, you should also specify the metric in the call the `load_model_hdf5()`. For example: `load_model_hdf5("my_model.h5", c('mean_pred' = metric_mean_pred))`.

Alternatively, you can wrap all of your code in a call to `with_custom_object_scope()` which will allow you to refer to the metric by name just like you do with built in keras metrics.

Documentation on the available backend tensor functions can be found at https://keras.rstudio.com/articles/backend.html#backend-functions.

### Metrics with Parameters

To use metrics with parameters (e.g. `metric_top_k_categorical_accurary()`) you should create a custom metric that wraps the call with the parameter. See below for an example.

### Note

Metric functions are to be supplied in the `metrics` parameter of the `compile.keras.engine.training.Model()` function.

### Examples

    ## Not run:

    # create metric using backend tensor functions
    metric_mean_pred <- custom_metric("mean_pred", function(y_true, y_pred) {
      k_mean(y_pred)
    })

    model %>% compile(
      optimizer = optimizer_rmsprop(),
      loss = loss_binary_crossentropy,
      metrics = c('accuracy', metric_mean_pred)
    )

    # create custom metric to wrap metric with parameter
    metric_top_3_categorical_accuracy <-
      custom_metric("top_3_categorical_accuracy", function(y_true, y_pred) {
        metric_top_k_categorical_accuracy(y_true, y_pred, k = 3)
      })

    model %>% compile(
      loss = 'categorical_crossentropy',
      optimizer = optimizer_rmsprop(),
      metrics = metric_top_3_categorical_accuracy
    )

    ## End(Not run)

[Package keras version 2.2.4 Index]