From 8ea573062af6e12061a52ac355acfc4915cc51c5 Mon Sep 17 00:00:00 2001
From: Martin Weinelt <hexa@darmstadt.ccc.de>
Date: Sat, 24 Jan 2026 03:18:46 +0100
Subject: [PATCH] python3Packages.filterpy: fix numpy 2.4 compat

---
 .../python-modules/filterpy/default.nix       |  2 +
 .../filterpy/numpy-2.4-compat.patch           | 69 +++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 pkgs/development/python-modules/filterpy/numpy-2.4-compat.patch

diff --git a/pkgs/development/python-modules/filterpy/default.nix b/pkgs/development/python-modules/filterpy/default.nix
index 11c103e5a040..110d3b136b0d 100644
--- a/pkgs/development/python-modules/filterpy/default.nix
+++ b/pkgs/development/python-modules/filterpy/default.nix
@@ -24,6 +24,8 @@ buildPythonPackage {
     hash = "sha256-KuuVu0tqrmQuNKYmDmdy+TU6BnnhDxh4G8n9BGzjGag=";
   };
 
+  patches = [ ./numpy-2.4-compat.patch ];
+
   build-system = [ setuptools ];
 
   dependencies = [
diff --git a/pkgs/development/python-modules/filterpy/numpy-2.4-compat.patch b/pkgs/development/python-modules/filterpy/numpy-2.4-compat.patch
new file mode 100644
index 000000000000..ab0969e54735
--- /dev/null
+++ b/pkgs/development/python-modules/filterpy/numpy-2.4-compat.patch
@@ -0,0 +1,69 @@
+diff --git a/filterpy/kalman/EKF.py b/filterpy/kalman/EKF.py
+index 5e83aec..06e9c42 100644
+--- a/filterpy/kalman/EKF.py
++++ b/filterpy/kalman/EKF.py
+@@ -406,7 +406,8 @@ class ExtendedKalmanFilter(object):
+         mahalanobis : float
+         """
+         if self._mahalanobis is None:
+-            self._mahalanobis = sqrt(float(dot(dot(self.y.T, self.SI), self.y)))
++            d2 = self.y.T @ self.SI @ self.y
++            self._mahalanobis = sqrt(np.asarray(d2).item())
+         return self._mahalanobis
+ 
+     def __repr__(self):
+diff --git a/filterpy/kalman/fading_memory.py b/filterpy/kalman/fading_memory.py
+index 36c9dcc..2c4d582 100644
+--- a/filterpy/kalman/fading_memory.py
++++ b/filterpy/kalman/fading_memory.py
+@@ -438,7 +438,7 @@ class FadingKalmanFilter(object):
+         mahalanobis : float
+         """
+         if self._mahalanobis is None:
+-            self._mahalanobis = sqrt(float(dot(dot(self.y.T, self.SI), self.y)))
++            self._mahalanobis = sqrt((self.y.T @ self.SI @ self.y).item())
+         return self._mahalanobis
+ 
+     def __repr__(self):
+diff --git a/filterpy/kalman/kalman_filter.py b/filterpy/kalman/kalman_filter.py
+index 994b596..0f72d85 100644
+--- a/filterpy/kalman/kalman_filter.py
++++ b/filterpy/kalman/kalman_filter.py
+@@ -1235,7 +1235,8 @@ class KalmanFilter(object):
+         mahalanobis : float
+         """
+         if self._mahalanobis is None:
+-            self._mahalanobis = sqrt(float(dot(dot(self.y.T, self.SI), self.y)))
++            d2 = dot(dot(self.y.T, self.SI), self.y)
++            self._mahalanobis = sqrt(np.asarray(d2).item())
+         return self._mahalanobis
+ 
+     @property
+diff --git a/filterpy/kalman/tests/test_imm.py b/filterpy/kalman/tests/test_imm.py
+index aa71fc2..ec2fdc1 100644
+--- a/filterpy/kalman/tests/test_imm.py
++++ b/filterpy/kalman/tests/test_imm.py
+@@ -176,8 +176,8 @@ def test_imm():
+ 
+     zs = np.zeros((N, 2))
+     for i in range(len(zs)):
+-        zs[i, 0] = simxs[i, 0] + randn()*r
+-        zs[i, 1] = simxs[i, 2] + randn()*r
++        zs[i, 0] = simxs[i, 0, 0] + randn()*r
++        zs[i, 1] = simxs[i, 2, 0] + randn()*r
+ 
+     '''
+     try:
+diff --git a/filterpy/leastsq/least_squares.py b/filterpy/leastsq/least_squares.py
+index 2610b14..6c5eb8f 100644
+--- a/filterpy/leastsq/least_squares.py
++++ b/filterpy/leastsq/least_squares.py
+@@ -129,7 +129,7 @@ class LeastSquaresFilter(object):
+ 
+         if self._order == 0:
+             K[0] = 1. / n
+-            y = z - x
++            y = z - x[0]
+             x[0] += K[0] * y
+ 
+         elif self._order == 1: