.ckpt file is often a checkpoint file related to machine learning models, particularly those trained using TensorFlow, a popular open-source machine learning library developed by Google.
In the context of TensorFlow, a checkpoint file (
.ckpt) is used to save the weights of a trained model or the state of a training process, so you can resume from where you left off or use the learned weights later for prediction, fine-tuning, etc. This is particularly useful for training deep learning models, which can take a long time to train. If, for any reason, the training process is interrupted, having a checkpoint can save you from starting over.
A TensorFlow checkpoint can consist of several files:
.ckpt.index: This file contains metadata about which weights are stored where. With the help of this file, TensorFlow knows which tensors are stored in which shard.
.ckpt.data-00000-of-00001: This file contains the values of weights, biases, and other variables. In distributed training, there might be multiple
checkpoint: This is a meta file which keeps the record of latest checkpoint files saved.
To restore or load a model from a checkpoint in TensorFlow, you would typically use the
tf.train.Saver classes, depending on the TensorFlow version.
When working with TensorFlow models, it’s also common to see models saved in the
SavedModel format (with a
.pb extension or in a directory structure) which not only contains the model’s weights but also its computation graph, allowing for easy deployment in various environments.