Mapping
Transform each individual observation in a dataset through mapping.
We'll cover the following...
Chapter Goals:
- Learn how to map a function onto each observation of a dataset
- Implement a function that creates a dataset of serialized protocol buffers and parses each observation
A. Mapping function
After initially creating a dataset from NumPy arrays or files, we oftentimes want to apply changes to make the dataset observations more useful. For example, we might create a dataset from heights measured in inches, but we want to train a model on the heights in centimeters. We can convert each observation to the desired format by using the map
function.
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import numpy as npimport tensorflow as tfdata = np.array([65.2, 70. ])d1 = tf.data.Dataset.from_tensor_slices(data)d2 = d1.map(lambda x:x * 2.54)print(d2)
In the example above, d1
is a dataset containing the height values from data
, measured in inches. We ...