studentscolab/iris_keras

Iris MLP Classifier (Keras / TensorFlow)

This repository contains a simple multiclass classifier for the classic Iris dataset, implemented as a small MLP (Multi-Layer Perceptron) in TensorFlow / Keras.
The model predicts one of three classes based on four numerical features.

Task

Tabular multiclass classification
Given the 4 iris measurements, predict the class:

• 0 → setosa
• 1 → versicolor
• 2 → virginica

Dataset

Iris dataset (from sklearn.datasets.load_iris)

Input features (4)

The model expects 4 float features in this exact order:

1. sepal length (cm)
2. sepal width (cm)
3. petal length (cm)
4. petal width (cm)

Target (3 classes)

• integer labels y ∈ {0,1,2}
• no one-hot encoding required (training uses sparse_categorical_crossentropy)

---

Model architecture

A small feed-forward network with built-in feature normalization:

Why Normalization layer?

The tf.keras.layers.Normalization layer learns feature-wise mean and variance from the training set via adapt(...).
This makes inference easier and safer: the same scaling used during training is embedded inside the saved model.

---

Training configuration

• Optimizer: Adam (learning_rate=1e-3)
• Loss: sparse_categorical_crossentropy
• Metric: accuracy
• Train/test split: 80/20 (stratify=y, random_state=42)
• Validation split (from train): 20% (validation_split=0.2)
• Epochs: 100
• Batch size: 16
• Reproducibility:
  • tf.random.set_seed(42)
  • np.random.seed(42)

Note: Exact accuracy may vary slightly across environments due to numerical differences and nondeterminism in some TF ops.

---

Example: training script (reference)

The model was trained using the following core logic (simplified):

normalizer = tf.keras.layers.Normalization(axis=-1)
normalizer.adapt(X_train.to_numpy())

model = tf.keras.Sequential([
    tf.keras.Input(shape=(4,)),
    normalizer,
    tf.keras.layers.Dense(16, activation="relu"),
    tf.keras.layers.Dense(16, activation="relu"),
    tf.keras.layers.Dense(3, activation="softmax"),
])

model.compile(
    optimizer=tf.keras.optimizers.Adam(learning_rate=1e-3),
    loss="sparse_categorical_crossentropy",
    metrics=["accuracy"]
)

model.fit(
    X_train.to_numpy(), y_train.to_numpy(),
    validation_split=0.2,
    epochs=100,
    batch_size=16,
    verbose=0
)

Example

import numpy as np
import pandas as pd
import tensorflow as tf
from huggingface_hub import hf_hub_download

filename = "iris_mlp.keras"
repo_id = "studentscolab/iris_keras"

model_path = hf_hub_download(repo_id=repo_id, filename=filename)

model = tf.keras.models.load_model(model_path)

x_new = pd.DataFrame([{
    "sepal length (cm)": 5.1,
    "sepal width (cm)": 3.5,
    "petal length (cm)": 1.4,
    "petal width (cm)": 0.2,
}])

proba = model.predict(x_new.to_numpy(), verbose=0)[0]  # shape: (3,)
pred  = int(np.argmax(proba))

print("Probabilities:", proba)
print("Predicted class:", pred)