ramjet.analysis.roc_calculator¶

Classes¶

class RocCalculator[source]¶

A class to calculate receiver operating characteristic (ROC) curves.

true_positive_rates :np.ndarray¶

Calculates the true positive rates for the accumulated confusion matrix counts for each threshold.

Returns:	The true positive rates for each threshold.

false_positive_rates :np.ndarray¶

Calculates the false positive rates for the accumulated confusion matrix counts for each threshold.

Returns:	The false positive rates for each threshold.

__init__(self)[source]¶

Initialize self. See help(type(self)) for accurate signature.

static threshold_predictions(probability_predictions: np.ndarray, thresholds: np.ndarray)[source]¶

From a 1D array of probability predictions, calculates a 2D array of binary predictions with each row corresponding to the predictions given one of the passed probability thresholds.

Parameters:	probability_predictions – The array of predicted probabilities for the binary labels. thresholds – The thresholds to generate binary labels on from the probabilities.
Returns:	The array containing the binary labels for each threshold.

static calculate_confusion_matrix_counts(label: np.ndarray, predictions: np.ndarray)[source]¶

Calculates the confusion matrix counts for a 1D set of true binary labels a 2D array of predictions, where each row corresponds to a prediction to compare.

Parameters:	label – A 1D binary array label. predictions – A 2D array of predictions, each row of which is to be compared to the label.
Returns:	The confusion matrix values for each row of the predictions.

accumulate_confusion_matrix_counts(self, label: np.ndarray, prediction: np.ndarray)[source]¶

Calculates the confusion matrix counts for a given label and probability prediction pair, and adds those counts to the totals.

Parameters:	label – The 1D array binary label. prediction – The 1D probability array prediction.

generate_roc_plot(self, output_path: Union[str, Path] = 'roc_curve.svg', title: str = None)[source]¶

Generates a ROC curve plot from the confusion matrix totals which have been accumulated.

Parameters:	output_path – The path to save the plot image file to. title – The title to add to the plot.