Calculate a percentage from the confusion matrix in TensorFlow.

tf_percent_confusion_metric.py

import tensorflow as tf

from tensorflow.python.ops.metrics_impl import _streaming_confusion_matrix


# almost the same as
def confusion_matrix(labels, predictions, num_classes, weights=None):
    total_cm, update_op = _streaming_confusion_matrix(
        labels, predictions, num_classes, weights=weights)

    def get_percentage(cm):
        row_sums = tf.reduce_sum(tf.to_float(cm), axis=1)

        # If the value of the denominator is 0, set it to 1 to avoid
        # zero division.
        denominator = tf.where(
            tf.greater(row_sums, 0), row_sums,
            tf.ones_like(row_sums))

        return tf.div(tf.to_float(cm), tf.reshape(denominator, (-1, 1)))

    percent_cm = get_percentage(total_cm)
    return percent_cm, update_op