tf.metrics.accuracy
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Calculates how often predictions
matches labels
.
tf.metrics.accuracy(
labels, predictions, weights=None, metrics_collections=None,
updates_collections=None, name=None
)
The accuracy
function creates two local variables, total
and
count
that are used to compute the frequency with which predictions
matches labels
. This frequency is ultimately returned as accuracy
: an
idempotent operation that simply divides total
by count
.
For estimation of the metric over a stream of data, the function creates an
update_op
operation that updates these variables and returns the accuracy
.
Internally, an is_correct
operation computes a Tensor
with elements 1.0
where the corresponding elements of predictions
and labels
match and 0.0
otherwise. Then update_op
increments total
with the reduced sum of the
product of weights
and is_correct
, and it increments count
with the
reduced sum of weights
.
If weights
is None
, weights default to 1. Use weights of 0 to mask values.
Args |
labels
|
The ground truth values, a Tensor whose shape matches
predictions .
|
predictions
|
The predicted values, a Tensor of any shape.
|
weights
|
Optional Tensor whose rank is either 0, or the same rank as
labels , and must be broadcastable to labels (i.e., all dimensions must
be either 1 , or the same as the corresponding labels dimension).
|
metrics_collections
|
An optional list of collections that accuracy should
be added to.
|
updates_collections
|
An optional list of collections that update_op should
be added to.
|
name
|
An optional variable_scope name.
|
Returns |
accuracy
|
A Tensor representing the accuracy, the value of total divided
by count .
|
update_op
|
An operation that increments the total and count variables
appropriately and whose value matches accuracy .
|
Raises |
ValueError
|
If predictions and labels have mismatched shapes, or if
weights is not None and its shape doesn't match predictions , or if
either metrics_collections or updates_collections are not a list or
tuple.
|
RuntimeError
|
If eager execution is enabled.
|
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Last updated 2020-10-01 UTC.
[null,null,["Last updated 2020-10-01 UTC."],[],[],null,["# tf.metrics.accuracy\n\n\u003cbr /\u003e\n\n|--------------------------------------------------------------------------------------------------------------------------------|\n| [View source on GitHub](https://github.com/tensorflow/tensorflow/blob/v1.15.0/tensorflow/python/ops/metrics_impl.py#L396-L458) |\n\nCalculates how often `predictions` matches `labels`.\n\n#### View aliases\n\n\n**Compat aliases for migration**\n\nSee\n[Migration guide](https://www.tensorflow.org/guide/migrate) for\nmore details.\n\n[`tf.compat.v1.metrics.accuracy`](/api_docs/python/tf/compat/v1/metrics/accuracy)\n\n\u003cbr /\u003e\n\n tf.metrics.accuracy(\n labels, predictions, weights=None, metrics_collections=None,\n updates_collections=None, name=None\n )\n\nThe `accuracy` function creates two local variables, `total` and\n`count` that are used to compute the frequency with which `predictions`\nmatches `labels`. This frequency is ultimately returned as `accuracy`: an\nidempotent operation that simply divides `total` by `count`.\n\nFor estimation of the metric over a stream of data, the function creates an\n`update_op` operation that updates these variables and returns the `accuracy`.\nInternally, an `is_correct` operation computes a `Tensor` with elements 1.0\nwhere the corresponding elements of `predictions` and `labels` match and 0.0\notherwise. Then `update_op` increments `total` with the reduced sum of the\nproduct of `weights` and `is_correct`, and it increments `count` with the\nreduced sum of `weights`.\n\nIf `weights` is `None`, weights default to 1. Use weights of 0 to mask values.\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Args ---- ||\n|-----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `labels` | The ground truth values, a `Tensor` whose shape matches `predictions`. |\n| `predictions` | The predicted values, a `Tensor` of any shape. |\n| `weights` | Optional `Tensor` whose rank is either 0, or the same rank as `labels`, and must be broadcastable to `labels` (i.e., all dimensions must be either `1`, or the same as the corresponding `labels` dimension). |\n| `metrics_collections` | An optional list of collections that `accuracy` should be added to. |\n| `updates_collections` | An optional list of collections that `update_op` should be added to. |\n| `name` | An optional variable_scope name. |\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Returns ------- ||\n|-------------|------------------------------------------------------------------------------------------------------------------|\n| `accuracy` | A `Tensor` representing the accuracy, the value of `total` divided by `count`. |\n| `update_op` | An operation that increments the `total` and `count` variables appropriately and whose value matches `accuracy`. |\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\n| Raises ------ ||\n|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `ValueError` | If `predictions` and `labels` have mismatched shapes, or if `weights` is not `None` and its shape doesn't match `predictions`, or if either `metrics_collections` or `updates_collections` are not a list or tuple. |\n| `RuntimeError` | If eager execution is enabled. |\n\n\u003cbr /\u003e"]]