diff options
Diffstat (limited to 'tensorflow/docs_src/performance/datasets_performance.md')
| -rw-r--r-- | tensorflow/docs_src/performance/datasets_performance.md | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/tensorflow/docs_src/performance/datasets_performance.md b/tensorflow/docs_src/performance/datasets_performance.md index 46b43b7673..5d9e4ba392 100644 --- a/tensorflow/docs_src/performance/datasets_performance.md +++ b/tensorflow/docs_src/performance/datasets_performance.md @@ -38,9 +38,9 @@ the heavy lifting of training your model. In addition, viewing input pipelines as an ETL process provides structure that facilitates the application of performance optimizations. -When using the @{tf.estimator.Estimator} API, the first two phases (Extract and +When using the `tf.estimator.Estimator` API, the first two phases (Extract and Transform) are captured in the `input_fn` passed to -@{tf.estimator.Estimator.train}. In code, this might look like the following +`tf.estimator.Estimator.train`. In code, this might look like the following (naive, sequential) implementation: ``` @@ -99,7 +99,7 @@ With pipelining, idle time diminishes significantly:  The `tf.data` API provides a software pipelining mechanism through the -@{tf.data.Dataset.prefetch} transformation, which can be used to decouple the +`tf.data.Dataset.prefetch` transformation, which can be used to decouple the time data is produced from the time it is consumed. In particular, the transformation uses a background thread and an internal buffer to prefetch elements from the input dataset ahead of the time they are requested. Thus, to @@ -130,7 +130,7 @@ The preceding recommendation is simply the most common application. ### Parallelize Data Transformation When preparing a batch, input elements may need to be pre-processed. To this -end, the `tf.data` API offers the @{tf.data.Dataset.map} transformation, which +end, the `tf.data` API offers the `tf.data.Dataset.map` transformation, which applies a user-defined function (for example, `parse_fn` from the running example) to each element of the input dataset. Because input elements are independent of one another, the pre-processing can be parallelized across @@ -164,7 +164,7 @@ dataset = dataset.map(map_func=parse_fn, num_parallel_calls=FLAGS.num_parallel_c Furthermore, if your batch size is in the hundreds or thousands, your pipeline will likely additionally benefit from parallelizing the batch creation. To this -end, the `tf.data` API provides the @{tf.contrib.data.map_and_batch} +end, the `tf.data` API provides the `tf.contrib.data.map_and_batch` transformation, which effectively "fuses" the map and batch transformations. To apply this change to our running example, change: @@ -205,7 +205,7 @@ is stored locally or remotely, but can be worse in the remote case if data is not prefetched effectively. To mitigate the impact of the various data extraction overheads, the `tf.data` -API offers the @{tf.contrib.data.parallel_interleave} transformation. Use this +API offers the `tf.contrib.data.parallel_interleave` transformation. Use this transformation to parallelize the execution of and interleave the contents of other datasets (such as data file readers). The number of datasets to overlap can be specified by the `cycle_length` argument. @@ -232,7 +232,7 @@ dataset = files.apply(tf.contrib.data.parallel_interleave( The throughput of remote storage systems can vary over time due to load or network events. To account for this variance, the `parallel_interleave` transformation can optionally use prefetching. (See -@{tf.contrib.data.parallel_interleave} for details). +`tf.contrib.data.parallel_interleave` for details). By default, the `parallel_interleave` transformation provides a deterministic ordering of elements to aid reproducibility. As an alternative to prefetching @@ -261,7 +261,7 @@ function (that is, have it operate over a batch of inputs at once) and apply the ### Map and Cache -The @{tf.data.Dataset.cache} transformation can cache a dataset, either in +The `tf.data.Dataset.cache` transformation can cache a dataset, either in memory or on local storage. If the user-defined function passed into the `map` transformation is expensive, apply the cache transformation after the map transformation as long as the resulting dataset can still fit into memory or @@ -281,9 +281,9 @@ performance (for example, to enable fusing of the map and batch transformations) ### Repeat and Shuffle -The @{tf.data.Dataset.repeat} transformation repeats the input data a finite (or +The `tf.data.Dataset.repeat` transformation repeats the input data a finite (or infinite) number of times; each repetition of the data is typically referred to -as an _epoch_. The @{tf.data.Dataset.shuffle} transformation randomizes the +as an _epoch_. The `tf.data.Dataset.shuffle` transformation randomizes the order of the dataset's examples. If the `repeat` transformation is applied before the `shuffle` transformation, @@ -296,7 +296,7 @@ internal state of the `shuffle` transformation. In other words, the former (`shuffle` before `repeat`) provides stronger ordering guarantees. When possible, we recommend using the fused -@{tf.contrib.data.shuffle_and_repeat} transformation, which combines the best of +`tf.contrib.data.shuffle_and_repeat` transformation, which combines the best of both worlds (good performance and strong ordering guarantees). Otherwise, we recommend shuffling before repeating. |