script/tutorial/57_EmbeddingCPython.js

@@ -0,0 +1,98 @@
+/////////////////////////////////////////////////////////////////////////////////////////////////// 
+// Embedding CPython with JEP: USe of numpy, pandas and matpplotlib in the same process.
+// Requires cpython.py to be put in the scripts folder, or else in the python path.
+/////////////////////////////////////////////////////////////////////////////////////////////////// 
+
+//Requirements to the use of JEP:
+// 1- PYTHONHOME is set to the python interpreter home folder.	
+// 2- jep*.so is in LD_LIBRARY_PATH (e.g. in extensions folder )
+// 3- jep*.jar is in the CLASS_PATH (e.g. in extensions folder )
+//JEP works with python 2 and 3.
+
+run("jeputils")
+
+//In order to use matplotlib we must set Tk backend before importing plt
+eval_jep("import matplotlib")
+eval_jep("matplotlib.use('TkAgg')")
+    
+
+//Evaluating statements
+eval_jep("import sys")
+eval_jep("import numpy as np")
+eval_jep("a = np.array((100, 100), )")
+eval_jep("print (a)")
+
+eval_jep("\
+def stderr(str):     \n\
+    if sys.version_info < (3,0) :\n\
+        exec(\"print >> sys.stderr, '\" + str + \"'\") \n\
+    else: \n\
+        exec(\"print ('\" + str + \"', file=sys.stderr)\") \n\
+")
+
+eval_jep("stderr('Testing stderr')")
+
+
+//Accessing a numpy array
+a=get_jep("a")
+print (a.getData()
+)
+print (a.getDimensions()
+)
+
+
+//Setting numpy array with scan data
+steps = [3,4]
+dims = [steps[0]+1 , steps[1]+1 ]
+r = ascan([m1,m2], [ai1], [0.0,0.0], [0.2,0.2], steps)
+data = r.getReadable(0)
+a = new_numpy_array(data, dims,'d')
+print (to_array(a.getDimensions()))
+print (to_array(a.getData()))
+plot( Convert.reshape(a.getData(),a.getDimensions()),null, null, null, "Scan Data")
+
+
+//Calling a module function
+b = call_jep("numpy", "transpose", [a,])
+print (to_array(b.getDimensions()))
+print (to_array(b.getData()))
+plot( Convert.reshape(b.getData(),b.getDimensions()),null, null, null, title="Transposed")
+
+
+
+
+//More calculations calling numpy
+a = call_jep("numpy", "ones", [[400,200],'d'])
+for (var i=0; i<100; i++){
+    b = call_jep("numpy", "ones", [[400,200],'d'])
+    a = call_jep("numpy", "add", [a,b])
+    s = call_jep("numpy", "sum", [a,])
+    print (a.getData()[0] + " " +  s
+)
+    sleep(0.001)
+}    
+
+//Calling a local function
+data = [1,2,3,4,5,6,7,8,9,0]
+dims = [2,5] 
+array = new_numpy_array(data, dims,'d') //Auxiliary function to create numpy arrays from lists or java arrays.
+ret = call_jep("cpython", "calc", [array,])
+print (ret.getDimensions() + " - " + ret.getData()
+)
+
+
+//Testing pandas
+ret = call_jep("cpython", "test_pandas")
+
+
+//Testing tkinter
+ret = call_jep("cpython", "test_tkinter")
+
+
+//Testing matplotlib
+ret = call_jep("cpython", "test_matplotlib", [0.1, 4, 0.4])
+
+
+//Running a modole
+run_jep("cpython")
+