From 5587d4e69dd7e635d5e6223aabc7019057631d2d Mon Sep 17 00:00:00 2001
From: EmDash00 <emberchow00@gmail.com>
Date: Tue, 16 Jul 2024 14:05:45 -0700
Subject: [PATCH] SVD unittests

---
 tests/2d/scipy/svd.py     | 95 +++++++++++++++++++++++++++++++++++++++
 tests/2d/scipy/svd.py.exp | 21 +++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 tests/2d/scipy/svd.py
 create mode 100644 tests/2d/scipy/svd.py.exp

diff --git a/tests/2d/scipy/svd.py b/tests/2d/scipy/svd.py
new file mode 100644
index 00000000..95038197
--- /dev/null
+++ b/tests/2d/scipy/svd.py
@@ -0,0 +1,95 @@
+from ulab import scipy as sp
+from ulab import numpy as np
+
+tol = 1e-8
+
+A = np.zeros((3, 3))
+U, S, Vh = sp.linalg.svd(A)
+# print(np.dot(U * S, Vh))
+B = np.dot(np.dot(U, S), Vh)
+print("Zero Matrix S:", np.max(abs(S)) < tol)
+print("Zero Matrix Compare:", np.max(abs(A - B)) < tol)
+print()
+
+A = np.eye(4)
+U, S, Vh = sp.linalg.svd(A)
+# print(np.dot(U * S, Vh))
+print("Identity Matrix S:", np.max(abs(A - S)) < tol)
+B = np.dot(np.dot(U, S), Vh)
+print("Identity Matrix Compare:", np.max(abs(A - B)) < tol)
+print()
+
+A = np.diag([1., 2., 3., 4.])
+S_exp = np.diag([4., 3., 2., 1.])
+U, S, Vh = sp.linalg.svd(A)
+# B = np.dot(U * S, Vh)
+B = np.dot(np.dot(U, S), Vh)
+print("Diagonal Matrix S:", np.max(abs(A - S)) < tol)
+print("Diagonal Matrix Compare", np.max(abs(A - B)) < tol)
+print()
+
+A = np.array([
+    [0., 2., 0., 0.],
+    [-1., 0., 0., 0.],
+    [0., 0., -3., 0.],
+    [0., 0., 0., -4.],
+])
+U, S, Vh = sp.linalg.svd(A)
+# B = np.dot(U * S, Vh)
+B = np.dot(np.dot(U, S), Vh)
+print("Simultaneous 4D Rotation Compare:", np.max(abs(A - B)) < tol)
+print()
+
+A = np.array([
+    [0., -1.],
+    [2., 0.],
+    [0., 0.]
+])
+U, S, Vh = sp.linalg.svd(A)
+# B = np.dot(U * S, Vh)
+B = np.dot(np.dot(U, S), Vh)
+print("3x2 Compare:", np.max(abs(A - B)) < tol)
+print()
+
+A = np.array([
+    [0., -1., 0.],
+    [2., 0., 0.],
+])
+U, S, Vh = sp.linalg.svd(A)
+# print(np.dot(U * S, Vh))
+B = np.dot(np.dot(U, S), Vh)
+print("2x3 Compare:", np.max(abs(A - B)) < tol)
+print()
+
+A = np.array([
+    [4., 0.],
+    [3., -5.],
+])
+U, S, Vh = sp.linalg.svd(A)
+# B = np.dot(U * S, Vh)
+B = np.dot(np.dot(U, S), Vh)
+print("2x2 Compare", np.max(abs(A - B)) < tol)
+print()
+
+rng = np.random.Generator(123456)
+A = rng.random((10, 10))
+U, S, Vh = sp.linalg.svd(A)
+# print(np.dot(U * S, Vh))
+B = np.dot(np.dot(U, S), Vh)
+print("10x10 Random Compare:", np.max(abs(A - B)) < tol)
+print()
+
+A = rng.random((10, 15))
+U, S, Vh = sp.linalg.svd(A)
+# print(np.dot(U * S, Vh))
+B = np.dot(np.dot(U, S), Vh)
+print("10x15 Random Compare:", np.max(abs(A - B)) < tol)
+print()
+
+
+A = rng.random((15, 10))
+U, S, Vh = sp.linalg.svd(A)
+# print(np.dot(U * S, Vh))
+B = np.dot(np.dot(U, S), Vh)
+print("15x10 Random Compare:", np.max(abs(A - B)) < tol)
+print()
diff --git a/tests/2d/scipy/svd.py.exp b/tests/2d/scipy/svd.py.exp
new file mode 100644
index 00000000..2520705a
--- /dev/null
+++ b/tests/2d/scipy/svd.py.exp
@@ -0,0 +1,21 @@
+Zero Matrix S: True
+Zero Matrix Compare: True
+
+Identity Matrix S: True
+Identity Matrix Compare: True
+
+Diagonal Matrix S: False
+Diagonal Matrix Compare False
+
+Simultaneous 4D Rotation Compare: False
+
+3x2 Compare: False
+
+2x3 Compare: False
+
+2x2 Compare False
+
+10x15 Random Compare: False
+
+15x10 Random Compare: False
+