Welcome to the world of machine learning, where computers learn from data and make predictions without explicit programming. At the heart of this technology lies the concept of a “model.”

## What is a Model

In traditional programming, we create functions/methods that receive inputs/parameters and return a result based on a formula. For example, imagine a Java method that applies the formula `y = 3x + 1`

.

```
public int formula(int x) {
return 3 * x + 1;
}
```

The above code would return the following data for `x`

and `y`

:

x | -1 | 0 | 1 | 2 | 3 | 4 |
---|---|---|---|---|---|---|

y | -2 | 1 | 4 | 7 | 10 | 13 |

Now, imagine that rather than the formula, you have lots of `x`

and `y`

values. You can create a machine learning model to discover the formula and predict new values.

As a real-life example, we can use the facial recognition that happens in the gallery of our phones. We have several inputs (photos) and outputs (people’s names) and the machine learning model is the formula that knows how to recognize people. As you give names to people in the photos, you’re feeding the model with data that is constantly retrained to better recognize those people.

## Python: The Language of Machine Learning

Python has become the de facto language for machine learning. Its vast ecosystem of libraries, including TensorFlow and Keras, makes it a powerhouse for building and training models. If you’re curious about stepping into the world of machine learning, Python is your trusty companion on this journey.

## Our Model

For simplicity, we’ll use the `x`

and `y`

data above to train a model that will know how to predict a `y`

value based on `x`

.

import tensorflow as tf import numpy as np from tensorflow import keras import os def build_model(): # Create a model that receives 1 input value and returns 1 output value model = tf.keras.Sequential([keras.layers.Dense(units=1, input_shape=[1])]) # Define the algorithms for learning. You don't need to worry about this for now model.compile(optimizer='sgd', loss='mean_squared_error') return model def train_model(model, xs, ys, epochs=500): # Train the model. Here we're saying the algorithm to try 500 random formulas to find the one that best matches # the input and output data. model.fit(xs, ys, epochs=epochs) def predict_with_model(model, input_data): # Predict using the trained model return model.predict([input_data]) def save_model(model, export_path): # Save the model tf.keras.models.save_model( model, export_path, overwrite=True, include_optimizer=True, save_format=None, signatures=None, options=None ) def main(): # Input data xs = np.array([-1.0, 0.0, 1.0, 2.0, 3.0, 4.0], dtype=float) ys = np.array([-2.0, 1.0, 4.0, 7.0, 10.0, 13.0], dtype=float) # Build the model model = build_model() # Train the model train_model(model, xs, ys) # Predict the value for x = 10. It will print a number very close to 31, like 30.9994 or something prediction = predict_with_model(model, 10.0) print(prediction) # Save the model model_dir = "./model" version = 1 export_path = os.path.join(model_dir, str(version)) print('export_path = {}\n'.format(export_path)) save_model(model, export_path) print('\nSaved model: ' + export_path) if __name__ == "__main__": main()

Run the above Python code to create, train, and test the model. It will create the model under the `./model`

directory.

## Serving the model

Once you created the model and have it under the `./model`

directory, you can serve it as a REST API. To do so, you can use the `tensorflow/serving`

container image:

```
podman run -p 8501:8501 \
--name=tf_serving \
--mount type=bind,source=./model,target=/models/model -e MODEL_NAME=model \
-t tensorflow/serving
```

## Consuming the model

Once your container is up and running, you can send a request to make an inference. Run the following command to infer the `y`

value for `x = 10`

:

```
curl -d '{"instances": [[10.0]]}' \
-H "Content-Type: application/json" \
-X POST http://localhost:8501/v1/models/model:predict
```

You should see a result similar to the following:

```
{
"predictions": [[30.9971237]
]
}
```

## That’s all Folks!

You’ve just created, trained, served, and consumed your first machine learning model. You can find the source code used in this post on GitHub. Feel free to ask any questions in the comments and stay tuned for more.