From 28fce491d087cb52fe0eb9bb98142c6d17bd200f Mon Sep 17 00:00:00 2001
From: David Rotermund <54365609+davrot@users.noreply.github.com>
Date: Tue, 19 Dec 2023 14:58:00 +0100
Subject: [PATCH] Create README.md

Signed-off-by: David Rotermund <54365609+davrot@users.noreply.github.com>
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 scikit-learn/pca/README.md | 42 ++++++++++++++++++++++++++++++++++++++
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+# PCA
+{:.no_toc}
+
+<nav markdown="1" class="toc-class">
+* TOC
+{:toc}
+</nav>
+
+## The goal
+
+
+Questions to [David Rotermund](mailto:davrot@uni-bremen.de)
+
+```python
+import numpy as np
+import matplotlib.pyplot as plt
+
+rng = np.random.default_rng(1)
+
+a_x = rng.normal(0.0, 1.0, size=(5000))[:, np.newaxis]
+a_y = rng.normal(0.0, 1.0, size=(5000))[:, np.newaxis] ** 3
+data_a = np.concatenate((a_x, a_y), axis=1)
+
+b_x = rng.normal(0.0, 1.0, size=(5000))[:, np.newaxis] ** 3
+b_y = rng.normal(0.0, 1.0, size=(5000))[:, np.newaxis]
+data_b = np.concatenate((b_x, b_y), axis=1)
+
+data = np.concatenate((data_a, data_b), axis=0)
+
+angle = -0.3
+
+roation_matrix = np.array(
+    [[np.cos(angle), -np.sin(angle)], [np.sin(angle), np.cos(angle)]]
+)
+data_r = data @ roation_matrix
+
+plt.plot(data[:, 0], data[:, 1], "b.")
+plt.plot(data_r[:, 0], data_r[:, 1], "r.")
+```
+
+![image0](image0.png)
+