Adding lkat test

examples/lkat_optimisation.py

+"""
+This example is a new feature regarding the use of Finesse as a shared library rather than 
+as an executable. It is still very experimental! The shared library is accessed using
+multiprocessing, which spawns an entire new process to run Finesse in. To use this requires
+firstly generating pylibkat.py, which involves generating a ctypes wrapper using 
+https://code.google.com/p/ctypesgen/. The command I use to generate the wrapper is:
+
+    /Users/ddb/svn/ctypesgen-read-only/ctypesgen.py -o pylibkat.py ./kat.h 
+
+You then also need to build libkat.so shared library from the python_shared branch of Finesse.
+Once the above is done the following script may or may not work...
+"""
+
+import ctypes
+import pylibkat
+import scipy
+from scipy.optimize import minimize
+import pylab
+import time
+import numpy as np
+from multiprocessing import Process, Manager, Value
+import pykat
+
+def callback(lkat, maxphi):
+    """
+    This callback will be run in a completly different process to that which this
+    script started. So we can't simply pass values back and forth. The callback
+    arguments are:
+        lkat - The handle to the finesse instance
+        maxphi - a shared object between this and the main process, see multiprocessing.Value
+    """
+    print "Entering callback..."
+    
+    # first we need to get a handle on the internals of Finesse
+    inter = pylibkat.interferometer.in_dll(lkat, "inter")
+    
+    m1 = inter.mirror_list[0]
+    m2 = inter.mirror_list[1]
+
+    circ = inter.output_data_list[0]
+    
+    def Fmin(x):
+        # change any variables we are interested in
+        m1.phi = x[0]
+        # now step the simulation forward
+        lkat._pykat_step()
+        # return our cost function
+        return -1 * circ.re       
+
+    minimize(Fmin, [maxphi.value], method='Nelder-Mead')
+
+    maxphi.value = m1.phi
+    
+    print "Process: Maximum power =", circ.re
+    print "Process: Mirror tuning =", m1.phi
+
+
+cmd = """
+l l1 1 0 n1
+s s1 1 n1 n2
+m m1 0.99 0.01 0 n2 n3
+s s2 100 n3 n4
+m m2 0.99 0.01 0 n4 n5
+pd circ n3
+
+noxaxis
+maxtem 2
+
+attr m1 Rc -1000
+attr m2 Rc 1000 
+cav c1 m1 n3 m2 n4
+"""
+
+kat = pykat.finesse.kat()
+
+kat.parseCommands(cmd)
+
+maxphi = Value('d', 100)
+
+p = kat.getProcess(callback, maxphi=maxphi)
+p.start()
+p.join()
+
+print "Host:    Received maximum phi =", maxphi.value

pykat/finesse.py

@@ -35,7 +35,7 @@ import warnings
 import re
 
 import itertools
-
+import ctypes
 import collections
 from collections import namedtuple, OrderedDict
 
@@ -52,10 +52,34 @@ import pykat.exceptions as pkex
 from PyQt4.QtCore import QCoreApplication
 from PyQt4.QtGui import QApplication
 
+from multiprocessing import Process, Manager
+
 NO_GUI = False
 NO_BLOCK = "NO_BLOCK"
 pykat_web = "www.gwoptics.org/pykat"
 
+def f__lkat_process(callback, cmd, kwargs):
+    """
+    """
+    lkat = ctypes.PyDLL("libkat.so.0")
+
+    try:
+        lkat._pykat_preInit() # must always be called, sets up
+                        # exception handling and such no simulation
+                        # specifc code here
+
+        # reads in the kat.ini and setups up other parts
+        lkat._pykat_init()
+        lkat._pykat_setup(cmd)
+    
+        callback(lkat, **kwargs)
+    
+    except Exception as ex: 
+        print "Exception caught in python: ", ex.message
+    finally:
+        # This should always be called no matter what
+        lkat._pykat_finish(0)
+        
 class katRun(object):
     def __init__(self):
         self.runDateTime = datetime.datetime.now()
@@ -576,7 +600,16 @@ class kat(object):
 
         except pkex.BasePyKatException as ex:
             print ex
+
             
+    def getProcess(self, callback, **kwargs):
+        """
+        """
+        
+        cmd = "\n".join(self.generateKatScript())
+        
+        return Process(target=f__lkat_process, args=(callback, cmd, kwargs))
+           
     def run(self, printout=0, printerr=0, save_output=False, save_kat=False,kat_name=None) :
         """ 
         Runs the current simulation setup that has been built thus far.