added custom value-to-color mapper

src/cristallina/plot.py

@@ -2,6 +2,7 @@ import re
 from collections import defaultdict
 
 import matplotlib
+import matplotlib as mpl
 from matplotlib import pyplot as plt
 
 import warnings
@@ -13,7 +14,7 @@ import numpy as np
 from tqdm import tqdm
 from matplotlib import patches
 from pathlib import Path
-import matplotlib as mpl
+
 from sfdata import SFDataFiles, sfdatafile, SFScanInfo
 import jungfrau_utils as ju
 
@@ -298,4 +299,9 @@ def line_plot_with_colorbar(xs,ys,colors, cmap=plt.cm.viridis,
         ax.set_ylabel(ylabel)
         
     # add colorbar
-    fig.colorbar(s_m,ax=ax,ticks=colors,label=cbar_label,alpha=alpha)
+    fig.colorbar(s_m,ax=ax,ticks=colors,label=cbar_label,alpha=alpha)
+
+
+def get_normalized_colormap(vmin, vmax, cmap=mpl.cm.viridis):
+    norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)
+    return lambda x: cmap(norm(x))