new script and save cmaps with caps

Author: vld-codra

colormaps/matplotlib_cmaps.py

@@ -0,0 +1,138 @@
+import os
+from typing import Callable
+
+import matplotlib.colors as pltc
+import matplotlib.pyplot as plt
+import numpy as np
+
+from plotpy.mathutils.colormap import (
+    DEFAULT_COLORMAPS,
+    DEFAULT_COLORMAPS_PATH,
+    EditableColormap,
+    save_colormaps,
+)
+
+
+def rgb_colors_to_hex_list(colors: list[tuple[int, int, int]]):
+    return [(i / len(colors), pltc.to_hex(color)) for i, color in enumerate(colors)]
+
+
+def _interpolate(val, vmin, vmax):
+    """Interpolate a color component between to values as provided
+    by matplotlib colormaps
+    """
+    interp = (val - vmin[0]) / (vmax[0] - vmin[0])
+    return (1 - interp) * vmin[1] + interp * vmax[2]
+
+
+def std_segmented_cmap_to_hex_list(cmdata: dict[str, list[tuple[float, float, float]]]):
+    """Setup a CustomQwtLinearColorMap according to
+    matplotlib's data
+    """
+    colors: list[tuple[float, str]] = []
+    red = np.array(cmdata["red"])
+    green = np.array(cmdata["green"])
+    blue = np.array(cmdata["blue"])
+    indices = sorted(set(red[:, 0]) | set(green[:, 0]) | set(blue[:, 0]))
+    for i in indices:
+        idxr = red[:, 0].searchsorted(i)
+        idxg = green[:, 0].searchsorted(i)
+        idxb = blue[:, 0].searchsorted(i)
+        compr = _interpolate(i, red[idxr - 1], red[idxr])
+        compg = _interpolate(i, green[idxg - 1], green[idxg])
+        compb = _interpolate(i, blue[idxb - 1], blue[idxb])
+        colors.append((i, pltc.to_hex((compr, compg, compb))))
+    return colors
+
+
+InterpFuncT = Callable[[np.ndarray], np.ndarray]
+
+
+def func_segmented_cmap_to_hex_list(
+    n: int,
+    cmap: pltc.LinearSegmentedColormap,
+):
+    colors = []
+    arr = np.linspace(0, 1, n, dtype=float)
+    colors = [(i, pltc.to_hex(rgba)) for i, rgba in zip(arr, cmap(arr))]
+    return colors
+
+
+def interp_to_descrete_cmap(cmap: EditableColormap) -> EditableColormap:
+    raw_cmap: tuple[tuple[float, str], ...] = cmap.to_tuples()
+    new_raw_cmap: list[tuple[float, str]] = [raw_cmap[0]]
+    n = len(raw_cmap)
+    coeff = (n - 1) / n
+    for i, (pos, color) in enumerate(raw_cmap[1:]):
+        prev_pos, prev_color = raw_cmap[i]
+        curr_pos, curr_color = pos, color
+        new_pos = curr_pos * coeff
+        print(curr_pos, new_pos, coeff)
+        new_raw_cmap.append((new_pos, prev_color))
+        new_raw_cmap.append((new_pos, curr_color))
+    new_raw_cmap.append(raw_cmap[-1])
+
+    return EditableColormap.from_iterable(new_raw_cmap, name=cmap.name)
+
+
+def main():
+
+    new_cmaps: dict[str, list[tuple[float, str]]] = {}
+
+    cmaps_with_colors = [
+        "magma",
+        "viridis",
+        "inferno",
+        "plasma",
+        "cividis",
+    ]
+
+    descrete_cmaps = [
+        "Pastel1",
+        "Pastel2",
+        "Paired",
+        "Accent",
+        "Dark2",
+        "Set1",
+        "Set2",
+        "Set3",
+    ]
+
+    cmaps_with_colors.extend(descrete_cmaps)
+
+    for cm_name in cmaps_with_colors:
+        cmap = plt.get_cmap(cm_name)
+        new_cmaps[cm_name] = rgb_colors_to_hex_list(cmap.colors)
+
+    for cm_name in descrete_cmaps:
+        cmap = EditableColormap.from_iterable(new_cmaps[cm_name], name=cm_name)
+        new_cmaps[cm_name] = list(interp_to_descrete_cmap(cmap).to_tuples())
+
+    segmented_cmaps = [
+        "coolwarm",
+        "bwr",
+        "seismic",
+    ]
+
+    for cm_name in segmented_cmaps:
+        cmap = plt.get_cmap(cm_name)
+        new_cmaps[cm_name] = std_segmented_cmap_to_hex_list(cmap._segmentdata)
+
+    n = 128
+    interp_cmaps = ["gnuplot2", "CMRmap", "rainbow", "turbo", "afmhot"]
+
+    for cm_name in interp_cmaps:
+        cmap = plt.get_cmap(cm_name)
+        new_cmaps[cm_name] = func_segmented_cmap_to_hex_list(n, cmap)
+
+    for name, raw_cm in new_cmaps.items():
+        DEFAULT_COLORMAPS[name.lower()] = EditableColormap.from_iterable(
+            raw_cm, name=name
+        )
+
+    json_file = os.path.join(os.path.dirname(__file__), "new_colormaps.json")
+    save_colormaps(json_file, DEFAULT_COLORMAPS_PATH)
+
+
+if __name__ == "__main__":
+    main()

plotpy/mathutils/colormap.py

@@ -159,7 +159,7 @@ def save_colormaps(json_filename: str, colormaps: CmapDictType):
         json_filename: json file name/path in which to save the colormaps
         colormaps: Dictionnary of colormpas names -> CustomQwtLinearColormap
     """
-    raw_colormaps = {name: cmap.to_tuples() for name, cmap in colormaps.items()}
+    raw_colormaps = {cmap.name: cmap.to_tuples() for cmap in colormaps.values()}
     json_abs_path = CONF.get_path(json_filename)
     with open(json_abs_path, "w", encoding="utf-8") as f:
         json.dump(raw_colormaps, f, indent=4)