fix: remove finite check from transform matrix and update transform method

Author: tlambert03

src/ndv/models/_array_display_model.py

@@ -218,8 +218,6 @@ def transform(self, matrix: np.ndarray) -> None:
         ary = np.asarray(matrix)
         if ary.shape != (4, 4):
             raise ValueError("Transform matrix must be 4x4.")
-        if not np.all(np.isfinite(ary)):
-            raise ValueError("Transform matrix must be finite.")
         # Decompose the matrix into scale and translation
         # Note: this assumes a proper affine transformation matrix
         self.scale = tuple(np.sqrt(np.sum(ary[:3, i] ** 2)) for i in range(3))[::-1]

src/ndv/views/_vispy/_array_canvas.py

@@ -99,7 +99,7 @@ def set_colormap(self, cmap: _cmap.Colormap) -> None:
         self._visual.cmap = cmap.to_vispy()
 
     def transform(self) -> np.ndarray:
-        return self._visual.transform  # type: ignore [no-any-return]
+        return self._visual.transform.matrix  # type: ignore [no-any-return]
 
     def set_transform(self, transform: np.ndarray) -> None:
         self._visual.transform = MatrixTransform(transform.T)

src/ndv/views/bases/_graphics/_canvas_elements.py

@@ -64,6 +64,8 @@ def colormap(self) -> _cmap.Colormap: ...
     @abstractmethod
     def set_colormap(self, cmap: _cmap.Colormap) -> None: ...
     @abstractmethod
+    def transform(self) -> np.ndarray: ...
+    @abstractmethod
     def set_transform(self, transform: np.ndarray) -> None: ...
 
     # -- LutView methods -- #

tests/test_controller.py

@@ -7,6 +7,7 @@
 from unittest.mock import MagicMock, Mock, patch
 
 import numpy as np
+import numpy.testing as npt
 import pytest
 
 from ndv._types import (
@@ -411,3 +412,17 @@ def assert_rgb_magic_works(rgb_data: np.ndarray) -> None:
 
     rgba_data = np.ones((1, 2, 3, 4, 4), dtype=np.uint8)
     assert_rgb_magic_works(rgba_data)
+
+
+@pytest.mark.usefixtures("any_app")
+def test_scale() -> None:
+    data = np.empty((8, 64, 64))
+    viewer = ArrayViewer(data, scale=(3, 1, 1))
+    viewer._request_data()
+    viewer._request_data()
+    viewer._request_data()
+    assert viewer.display_model.scale == (3, 1, 1)
+    handles = viewer._lut_controllers[None].handles
+    viewer._join()
+    tform = handles[0].transform()
+    npt.assert_array_equal(tform, np.diag((1.0, 1, 3, 1)))