foolbox.utils
¶
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foolbox.utils.
softmax
(logits)[source]¶ Transforms predictions into probability values.
Parameters: - logits : array_like
The logits predicted by the model.
Returns: - numpy.ndarray
Probability values corresponding to the logits.
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foolbox.utils.
crossentropy
(label, logits)[source]¶ Calculates the cross-entropy.
Parameters: - logits : array_like
The logits predicted by the model.
- label : int
The label describing the target distribution.
Returns: - float
The cross-entropy between softmax(logits) and onehot(label).
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foolbox.utils.
batch_crossentropy
(label, logits)[source]¶ Calculates the cross-entropy for a batch of logits.
Parameters: - logits : array_like
The logits predicted by the model for a batch of inputs.
- label : int
The label describing the target distribution.
Returns: - np.ndarray
The cross-entropy between softmax(logits[i]) and onehot(label) for all i.
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foolbox.utils.
binarize
(x, values, threshold=None, included_in='upper')[source]¶ Binarizes the values of x.
Parameters: - values : tuple of two floats
The lower and upper value to which the inputs are mapped.
- threshold : float
The threshold; defaults to (values[0] + values[1]) / 2 if None.
- included_in : str
Whether the threshold value itself belongs to the lower or upper interval.
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foolbox.utils.
imagenet_example
(shape=(224, 224), data_format='channels_last', bounds=(0, 255))[source]¶ Returns an example image and its imagenet class label.
Parameters: - shape : list of integers
The shape of the returned image.
- data_format : str
“channels_first” or “channels_last”
- bounds : tuple
smallest and largest allowed pixel value
Returns: - image : array_like
The example image.
- label : int
The imagenet label associated with the image.
- NOTE: This function is deprecated and will be removed in the future.
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foolbox.utils.
samples
(dataset='imagenet', index=0, batchsize=1, shape=(224, 224), data_format='channels_last', bounds=(0, 255))[source]¶ Returns a batch of example images and the corresponding labels
Parameters: - dataset : string
The data set to load (options: imagenet, mnist, cifar10, cifar100, fashionMNIST)
- index : int
For each data set 20 example images exist. The returned batch contains the images with index [index, index + 1, index + 2, …]
- batchsize : int
Size of batch.
- shape : list of integers
The shape of the returned image (only relevant for Imagenet).
- data_format : str
“channels_first” or “channels_last”
- bounds : tuple
smallest and largest allowed pixel value
Returns: - images : array_like
The batch of example images
- labels : array of int
The labels associated with the images.
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foolbox.utils.
onehot_like
(a, index, value=1)[source]¶ Creates an array like a, with all values set to 0 except one.
Parameters: - a : array_like
The returned one-hot array will have the same shape and dtype as this array
- index : int
The index that should be set to value
- value : single value compatible with a.dtype
The value to set at the given index
Returns: - numpy.ndarray
One-hot array with the given value at the given location and zeros everywhere else.