Improve default interpolation performance

colour-science · May 9, 2023 · 009700b · 009700b
1 parent b75f3e1
commit 009700b
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Showing 2 changed files with 14 additions and 33 deletions.
diff --git a/colour/algebra/interpolation.py b/colour/algebra/interpolation.py
@@ -1222,38 +1222,18 @@ def _evaluate(self, x: NDArrayFloat) -> NDArrayFloat:
             X = sdiv(x - self._xp[i], self._xp[i + 1] - self._xp[i])
 
         r = self._yp
+        r_stacked = np.transpose(
+            as_float_array(
+                [r[i - 2], r[i - 1], r[i], r[i + 1], r[i + 2], r[i + 3]]
+            )
+        )
 
         a0p = r[i]
-        a1p = (
-            2 * r[i - 2] - 16 * r[i - 1] + 16 * r[i + 1] - 2 * r[i + 2]
-        ) / 24
-        a2p = (
-            -r[i - 2] + 16 * r[i - 1] - 30 * r[i] + 16 * r[i + 1] - r[i + 2]
-        ) / 24
-        a3p = (
-            -9 * r[i - 2]
-            + 39 * r[i - 1]
-            - 70 * r[i]
-            + 66 * r[i + 1]
-            - 33 * r[i + 2]
-            + 7 * r[i + 3]
-        ) / 24
-        a4p = (
-            13 * r[i - 2]
-            - 64 * r[i - 1]
-            + 126 * r[i]
-            - 124 * r[i + 1]
-            + 61 * r[i + 2]
-            - 12 * r[i + 3]
-        ) / 24
-        a5p = (
-            -5 * r[i - 2]
-            + 25 * r[i - 1]
-            - 50 * r[i]
-            + 50 * r[i + 1]
-            - 25 * r[i + 2]
-            + 5 * r[i + 3]
-        ) / 24
+        a1p = np.sum(r_stacked * [2, -16, 0, 16, -2, 0] / 24, axis=1)
+        a2p = np.sum(r_stacked * [-1, 16, -30, 16, -1, 0] / 24, axis=1)
+        a3p = np.sum(r_stacked * [-9, 39, -70, 66, -33, 7] / 24, axis=1)
+        a4p = np.sum(r_stacked * [13, -64, 126, -124, +61, -12] / 24, axis=1)
+        a5p = np.sum(r_stacked * [-5, 25, -50, 50, -25, 5] / 24, axis=1)
 
         y = (
             a0p

diff --git a/colour/colorimetry/generation.py b/colour/colorimetry/generation.py
@@ -33,6 +33,7 @@
 """
 
 from __future__ import annotations
+from colour.algebra.interpolation import LinearInterpolator
 
 import numpy as np
 
@@ -123,7 +124,7 @@ def sd_constant(
     100.0
     """
 
-    settings = {"name": f"{k} Constant"}
+    settings = {"name": f"{k} Constant", "interpolator": LinearInterpolator}
     settings.update(kwargs)
 
     values = full(len(shape.wavelengths), k)
@@ -256,7 +257,7 @@ def msds_constant(
     ['a', 'b', 'c']
     """
 
-    settings = {"name": f"{k} Constant"}
+    settings = {"name": f"{k} Constant", "interpolator": LinearInterpolator}
     settings.update(kwargs)
 
     wavelengths = shape.wavelengths
@@ -755,7 +756,7 @@ def sd_multi_leds_Ohno2005(
 
     sd = sd_zeros(shape)
 
-    for (peak_wavelength, fwhm_s, peak_power_ratio) in zip(
+    for peak_wavelength, fwhm_s, peak_power_ratio in zip(
         peak_wavelengths, fwhm, peak_power_ratios
     ):
         sd += (