Introduced test for random number generation

Author: giadarol

examples/radiation/000_test_rng.py renamed to examples/radiation/000_random_generation.py

@@ -6,8 +6,8 @@
 from pathlib import Path
 
 ctx = xo.ContextCpu()
-ctx = xo.ContextCupy()
-ctx = xo.ContextPyopencl()
+#ctx = xo.ContextCupy()
+#ctx = xo.ContextPyopencl()
 
 part = xt.Particles(_context=ctx, p0c=6.5e12, x=[1,2,3])
 part._init_random_number_generator()
@@ -34,6 +34,7 @@ class TestElement(xt.BeamElement):
 
 telem.track(part)
 
+# Use turn-by-turn monitor to acquire some statistics
 
 tracker = xt.Tracker(_buffer=telem._buffer,
         sequence=xl.Line(elements=[telem],

tests/test_random_gen.py

@@ -0,0 +1,56 @@
+import numpy as np
+
+import xobjects as xo
+import xtrack as xt
+import xline as xl
+from pathlib import Path
+def test_random_generation():
+    for ctx in xo.context.get_test_contexts():
+        print(f'{ctx}')
+
+        part = xt.Particles(_context=ctx, p0c=6.5e12, x=[1,2,3])
+        part._init_random_number_generator()
+
+        class TestElement(xt.BeamElement):
+             _xofields={
+                'dummy': xo.Float64,
+                }
+        TestElement.XoStruct.extra_sources = [
+            xt._pkg_root.joinpath(
+                'random_number_generator/rng_src/base_rng.h'),
+            xt._pkg_root.joinpath(
+                'random_number_generator/rng_src/local_particle_rng.h'),
+            ]
+        TestElement.XoStruct.extra_sources.append('''
+        /*gpufun*/
+        void TestElement_track_local_particle(
+                  TestElementData el, LocalParticle* part0){
+            //start_per_particle_block (part0->part)
+                double rr = LocalParticle_generate_random_double(part);
+                LocalParticle_set_x(part, rr);
+            //end_per_particle_block
+        }
+        ''')
+
+        telem = TestElement(_context=ctx)
+
+        telem.track(part)
+
+        # Use turn-by turin monitor to acquire some statistics
+
+        tracker = xt.Tracker(_buffer=telem._buffer,
+                sequence=xl.Line(elements=[telem],
+                    element_names='test_element'),
+                    save_source_as='source.c')
+
+        tracker.track(part, num_turns=1e6, turn_by_turn_monitor=True)
+
+        import matplotlib.pyplot as plt
+        plt.close('all')
+        for i_part in range(part._capacity):
+            x = tracker.record_last_track.x[i_part, :]
+            assert np.all(x>0)
+            assert np.all(x<1)
+            hstgm, bin_edges = np.histogram(x,  bins=50, range=(0, 1), density=True)
+            assert np.allclose(hstgm, 1, rtol=1e-10, atol=0.03)
+