Merge pull request #2468 from EdgarGF93/fakedata_background

Fakedata background

Author: kif

src/pyFAI/calibrant.py

@@ -667,13 +667,14 @@ def get_peaks(self, unit: str="2th_deg"):
 
         return values * scale
 
-    def fake_calibration_image(self, ai, shape=None, Imax=1.0,
-                               U=0, V=0, W=0.0001) -> numpy.ndarray:
+    def fake_calibration_image(self, ai, shape=None, Imax=1.0, Imin=0.0,
+                               U=0, V=0, W=0.0001,
+                               ) -> numpy.ndarray:
         """
         Generates a fake calibration image from an azimuthal integrator.
-
         :param ai: azimuthal integrator
         :param Imax: maximum intensity of rings
+        :param Imin: minimum intensity of the signal (background)
         :param U, V, W: width of the peak from Caglioti's law (FWHM^2 = Utan(th)^2 + Vtan(th) + W)
         """
         if shape is None:
@@ -709,8 +710,11 @@ def fake_calibration_image(self, ai, shape=None, Imax=1.0,
                 break
             else:
                 signal += Imax * numpy.exp(-(tth_1d - t) ** 2 / (2.0 * sigma2))
+        signal = (Imax - Imin) * signal + Imin
+
         res = ai.calcfrom1d(tth_1d, signal, shape=shape, mask=ai.mask,
                             dim1_unit='2th_rad', correctSolidAngle=True)
+
         return res
 
     def __getnewargs_ex__(self):