Two intertwined spirals - the ultimate quantum ML challenge
Samples
300
Features
2 (X, Y coordinates)
Classes
2 (Binary)
Difficulty
Hard
The Spirals dataset is one of the most challenging binary classification problems. Two intertwined spirals rotate around a common center with different angular velocities. This dataset severely tests the expressiveness of any machine learning model and is an excellent testbed for demonstrating quantum advantage in learning complex, highly non-linear patterns.

where n = feature dimension
where:
Each spiral can be parameterized in polar coordinates as a curve where the distance from origin increases with angle.
Spiral parameterization:
Cartesian conversion:
Epochs Recommended
500-1000 (significantly more than simpler datasets)
Learning Rate
0.01 - 0.05 (may require careful tuning)
Convergence Time
Slower than other datasets - barren plateaus possible