Hide matplotlib to make buildbot builds passing (arch, yaketty)

Examples/python/fitting/ex01_SampleParametersIntro/SampleParametersIntro.py

@@ -9,7 +9,7 @@ fitting; it serves as a gentle introduction to other fitting examples.
 from __future__ import print_function
 import bornagain as ba
 from bornagain import deg, angstrom, nm
-from matplotlib import pyplot as plt
+
 
 def get_sample():
     """
@@ -110,6 +110,7 @@ def plot(results):
     Draw results of several simulations on canvas
     """
 
+    from matplotlib import pyplot as plt
     plt.figure(figsize=(12.80, 10.24))
 
     for nplot, hist in results.items():

Examples/python/simulation/ex01_BasicParticles/AllFormFactorsAvailable.py

@@ -4,7 +4,6 @@ All formfactors available in BornAgain in the Born Approximation
 import numpy
 import bornagain as ba
 from bornagain import deg, angstrom
-import matplotlib
 from matplotlib import pyplot as plt
 
 phi_min, phi_max = -2.0, 2.0

Examples/python/simulation/ex05_BeamAndDetector/SpecularSimulation.py

@@ -77,7 +77,6 @@ def plot(simulation):
     """
     Plots results for several selected layers
     """
-    import matplotlib
     from matplotlib import pyplot as plt
     fig = plt.figure(figsize=(12.80, 10.24))