small improvements

knodlseder
1 parent 8bcf40c9
Showing 1 changed file with 65 additions and 775 deletions
scripts/obsutils.py
 # ==========================================================================
 # This script provides a number of functions that are useful for handling
-# CTA data.
+# CTA observations.
 #
 # Copyright (C) 2011 Jurgen Knodlseder
 #
@@ -20,7 +20,7 @@
 # ==========================================================================
 from ctatools import *
 from gammalib import *
-from math import *
+#from math import *
 #import os
 #import glob
 #import sys
@@ -32,7 +32,7 @@ from math import *
 # ===================== #
 # Simulate observations #
 # ===================== #
-def sim_obs(obs, log=False, seed=0, nbins=0, binsz=0.05, npix=200):
+def sim(obs, log=False, debug=True, seed=0, nbins=0, binsz=0.05, npix=200):
 	"""
 	Simulate events for all observations in the container.
@@ -40,6 +40,7 @@ def sim_obs(obs, log=False, seed=0, nbins=0, binsz=0.05, npix=200):
 	 obs   - Observation container
 	Keywords:
 	 log   - Create log file(s)
+	 debug - Create screen dump
 	 seed  - Seed value for simulations (default: 0)
 	 nbins - Number of energy bins (default: 0=unbinned)
 	 binsz - Pixel size for binned simulation (deg/pixel)
@@ -52,6 +53,10 @@ def sim_obs(obs, log=False, seed=0, nbins=0, binsz=0.05, npix=200):
 	# Optionally open the log file
 	if log:
 		sim.logFileOpen()
+
+	# Optionally switch-on debugging model
+	if debug:
+		sim["debug"].boolean(True)
 	# Run ctobssim application. This will loop over all observations in the
 	# container and simulation the events for each observation. Note that
@@ -92,6 +97,10 @@ def sim_obs(obs, log=False, seed=0, nbins=0, binsz=0.05, npix=200):
 		if log:
 			bin.logFileOpen()
+		# Optionally switch-on debugging model
+		if debug:
+			bin["debug"].boolean(True)
+
 		# Run ctbin application. This will loop over all observations in
 		# the container and bin the events in counts maps
 		bin.run()
@@ -115,14 +124,15 @@ def sim_obs(obs, log=False, seed=0, nbins=0, binsz=0.05, npix=200):
 # ================ #
 # Fit observations #
 # ================ #
-def fit_obs(obs, log=False):
+def fit(obs, log=False, debug=False):
 	"""
 	Perform maximum likelihood fitting of observations in the container.
 	Parameters:
-	 obs - Observation container
+	 obs   - Observation container
 	Keywords:
-	 log - Create log file(s)
+	 log   - Create log file(s)
+	 debug - Create screen dump
 	"""
 	# Allocate ctlike application
 	like = ctlike(obs)
@@ -130,6 +140,9 @@ def fit_obs(obs, log=False):
 	# Optionally open the log file
 	if log:
 		like.logFileOpen()
+	
+	# Optionally switch-on debugging model
+	if debug:
 		like["debug"].boolean(True)
 	# Run ctlike application.
@@ -142,25 +155,27 @@ def fit_obs(obs, log=False):
 # ================= #
 # Create counts map #
 # ================= #
-def make_counts_map(obs, proj="TAN", coord="GAL", xval=0.0, yval=0.0, \
-                         nxpix=600, nypix=200, pixsize=0.05, \
-						 outname="survey_cntmap.fits"):
+def cntmap(obs, proj="TAN", coord="GAL", xval=0.0, yval=0.0, \
+           binsz=0.05, nxpix=200, nypix=200, \
+		   outname="cntmap.fits"):
 	"""
 	Creates a counts map by combining the events of all observations.
 	The counts map will be a summed map over all energies.
 	Parameters:
-	 obs - Observation container
+	 obs     - Observation container
 	Keywords:
-	 xval    - Reference longitude value [deg]
-	 yval    - Reference latitude value [deg]
-	 nxpix   - Number of pixels in longitude axis
-	 nypix   - Number of pixels in latitude axis
-	 pixsize - Pixel size [deg]
-	 outname - Counts map FITS filename
+	 proj    - Projection type (e.g. TAN, CAR, STG, ...) (default: TAN)
+	 coord   - Coordinate type (GAL, CEL) (default: GAL)
+	 xval    - Reference longitude value [deg] (default: 0.0)
+	 yval    - Reference latitude value [deg] (default: 0.0)
+	 binsz   - Pixel size [deg/pixel] (default: 0.05)
+	 nxpix   - Number of pixels in X direction (default: 200)
+	 nypix   - Number of pixels in Y direction (default: 200)
+	 outname - Counts map FITS filename (default: cntmap.fits)
 	"""
 	# Allocate counts map
-	cntmap = GSkymap(proj, coord, xval, yval, -pixsize, pixsize, nxpix, nypix, 1)
+	map = GSkymap(proj, coord, xval, yval, -binsz, binsz, nxpix, nypix, 1)
 	# Fill all observations
 	for run in obs:
@@ -173,43 +188,45 @@ def make_counts_map(obs, proj=&quot;TAN&quot;, coord=&quot;GAL&quot;, xval=0.0, yval=0.0, \
 			# Determine sky pixel
 			skydir = event.dir().skydir()
-			pixel  = cntmap.dir2pix(skydir)
+			pixel  = map.dir2pix(skydir)
 			# Set pixel
-			cntmap[pixel] += 1.0
+			map[pixel] += 1.0
 	# Save sky map. The clobber flag is set to True, so any existing FITS
 	# file will be overwritten.
-	cntmap.save(outname, True)
+	map.save(outname, True)
 	# Return counts map
-	return cntmap
+	return map
 # ================ #
 # Create model map #
 # ================ #
-def make_model_map(obs, eref=0.1, proj="TAN", coord="GAL", xval=0.0, yval=0.0, \
-						nxpix=600, nypix=200, pixsize=0.05, \
-						outname="survey_modmap.fits"):
+def modmap(obs, eref=0.1, proj="TAN", coord="GAL", xval=0.0, yval=0.0, \
+           binsz=0.05, nxpix=200, nypix=200, \
+           outname="modmap.fits"):
 	"""
 	Make model map for a given reference energy by combining all observations.
 	The model map will be evaluated for a given reference energy 'eref' and will
 	be given in units of [counts/(sr MeV s)].
 	Parameters:
-	 obs - Observation container
+	 obs     - Observation container
 	Keywords:
-	 eref    - Reference energy for which model is created [TeV]
-	 xval    - Reference longitude value [deg]
-	 yval    - Reference latitude value [deg]
-	 nxpix   - Number of pixels in longitude axis
-	 nypix   - Number of pixels in latitude axis
-	 pixsize - Pixel size [deg]
-	 outname - Counts map FITS filename
+	 eref    - Reference energy for which model is created [TeV] (default: 0.1)
+	 proj    - Projection type (e.g. TAN, CAR, STG, ...) (default: TAN)
+	 coord   - Coordinate type (GAL, CEL) (default: GAL)
+	 xval    - Reference longitude value [deg] (default: 0.0)
+	 yval    - Reference latitude value [deg] (default: 0.0)
+	 binsz   - Pixel size [deg/pixel] (default: 0.05)
+	 nxpix   - Number of pixels in X direction (default: 200)
+	 nypix   - Number of pixels in Y direction (default: 200)
+	 outname - Model map FITS filename (default: modmap.fits)
 	"""
 	# Allocate model map
-	modmap = GSkymap(proj, coord, xval, yval, -pixsize, pixsize, nxpix, nypix, 1)
+	map = GSkymap(proj, coord, xval, yval, -binsz, binsz, nxpix, nypix, 1)
 	# Set reference energy, time and direction. The time is not initialised and is
 	# in fact not used (as the IRF is assumed to be time independent for now).
@@ -220,10 +237,10 @@ def make_model_map(obs, eref=0.1, proj=&quot;TAN&quot;, coord=&quot;GAL&quot;, xval=0.0, yval=0.0, \
 	energy.TeV(eref)
 	# Loop over all map pixels
-	for pixel in range(modmap.npix()):
+	for pixel in range(map.npix()):
 		# Get sky direction
-		skydir = modmap.pix2dir(pixel)
+		skydir = map.pix2dir(pixel)
 		instdir.skydir(skydir)
 		# Create event atom for map pixel
@@ -240,21 +257,21 @@ def make_model_map(obs, eref=0.1, proj=&quot;TAN&quot;, coord=&quot;GAL&quot;, xval=0.0, yval=0.0, \
 			value += obs.models().eval(atom, run)
 		# Set map value
-		modmap[pixel] = value
+		map[pixel] = value
 	# Save sky map
-	modmap.save(outname, True)
+	map.save(outname, True)
 	# Return model map
-	return modmap
+	return map
 # ======================= #
 # Set one CTA observation #
 # ======================= #
-def set_one_obs(pntdir, tstart=0.0, duration=1800.0, \
-                emin=0.1, emax=100.0, rad=5.0, \
-                irf="kb_E_50h_v3", caldb="/usr/local/gamma/share/caldb/cta"):
+def set(pntdir, tstart=0.0, duration=1800.0, \
+        emin=0.1, emax=100.0, rad=5.0, \
+        irf="kb_E_50h_v3", caldb="$GAMMALIB/share/caldb/cta"):
 	"""
 	Returns a single CTA observation. By looping over this function we can
 	add CTA observations to the observation container.
@@ -262,13 +279,13 @@ def set_one_obs(pntdir, tstart=0.0, duration=1800.0, \
 	Parameters:
 	 pntdir   - Pointing direction
 	Keywords:
-	 tstart   - Start time [seconds]
-	 duration - Duration of observation [seconds]
-	 emin     - Minimum event energy [TeV]
-	 emax     - Maximum event energy [TeV]
-	 rad      - ROI radius used for analysis [deg]
-	 irf      - Instrument response function
-	 caldb    - Calibration database path
+	 tstart   - Start time [seconds] (default: 0.0)
+	 duration - Duration of observation [seconds] (default: 1800.0)
+	 emin     - Minimum event energy [TeV] (default: 0.1)
+	 emax     - Maximum event energy [TeV] (default: 100.0)
+	 rad      - ROI radius used for analysis [deg] (default: 5.0)
+	 irf      - Instrument response function (default: kb_E_50h_v3)
+	 caldb    - Calibration database path (default: $GAMMALIB/share/caldb/cta)
 	"""
 	# Allocate CTA observation
 	obs = GCTAObservation()
@@ -310,733 +327,6 @@ def set_one_obs(pntdir, tstart=0.0, duration=1800.0, \
 	# Set instrument response
 	obs.response(irf, caldb)
-	#print obs
 	# Return observation
 	return obs
-
-
-# ================== #
-# Setup source model #
-# ================== #
-def add_source_model(models, source):
-	"""
-	This function adds one source model to the observations container.
-
-	Parameters:
-	 obs    - Observations container
-	 source - Source to be added to container
-	"""
-	# Append source to model container
-	models.append(source)
-	
-	# Return model container
-	return models
-
-
-# ======================================== #
-# Add CTA background model to observations #
-# ======================================== #
-def add_background_model(models):
-	"""
-	Add standard CTA background model to observations container.
-	We use a simple power law here, scaled to Konrad's E configuration
-	performance table.
-
-	Parameters:
-	 obs - Observation container
-	"""
-	# Define background model
-	bgd_radial   = GCTAModelRadialGauss(3.0)
-	bgd_spectrum = GModelSpectralPlaw(61.8, -1.85)
-	bgd_spectrum["Prefactor"].scale(1.0e-6)
-	bgd_spectrum["PivotEnergy"].value(1.0)
-	bgd_spectrum["PivotEnergy"].scale(1.0e6)
-	bgd_model = GCTAModelRadialAcceptance(bgd_radial, bgd_spectrum)
-	bgd_model.name("Background")
-	bgd_model.instruments("CTA")
-	
-	# Add background model to container
-	models.append(bgd_model)
-	
-	# Return model container
-	return models
-
-
-# ==================== #
-# Set Crab-like source #
-# ==================== #
-def crab_like(name, l, b, flux=1.0, type="point", sigma=1.0, radius=1.0, width=0.1, \
-              fitpos=True):
-	"""
-	Returns a single source with Crab-like spectrum. The source flux
-	can be scaled in Crab units.
-
-	Parameters:
-	 name   - Unique source name
-	 l      - Galactic longitude of source location [deg]
-	 b      - Galactic latitude of source location [deg]
-	Keywords:
-	 flux   - Source flux in Crab units
-	 type   - Source type ("point", "gauss", "disk", "shell")
-	 sigma  - Gaussian sigma (for type="gauss")
-	 radius - Disk or shell inner radius [deg] (for type="disk" and type="shell")
-	 width  - Shell width [deg] (for type="shell")
-	 fitpos - Specifies if position should be fitted or not
-	"""
-	# Set source location
-	location = GSkyDir()
-	location.lb_deg(l, b)
-	
-	# Set source spectrum
-	spectrum = crab_spec(flux=flux)
-
-	# Set source
-	if type == "point":
-		spatial = GModelSpatialPtsrc(location)
-		if fitpos:
-			spatial[0].free()
-			spatial[1].free()
-		source  = GModelPointSource(spatial, spectrum)
-	elif type == "gauss":
-		radial = GModelRadialGauss(location, sigma)
-		if fitpos:
-			radial[0].free()
-			radial[1].free()
-		source = GModelExtendedSource(radial, spectrum)
-	elif type == "disk":
-		radial = GModelRadialDisk(location, radius)
-		if fitpos:
-			radial[0].free()
-			radial[1].free()
-		source = GModelExtendedSource(radial, spectrum)
-	elif type == "shell":
-		radial = GModelRadialShell(location, radius, width)
-		if fitpos:
-			radial[0].free()
-			radial[1].free()
-		source = GModelExtendedSource(radial, spectrum)
-	else:
-		print "ERROR: Unknown source type '"+type+"'."
-		return None
-	
-	# Set source name
-	source.name(name)
-	
-	# Return source
-	return source
-
-
-# ================= #
-# Set Crab spectrum #
-# ================= #
-def crab_spec(flux=1.0):
-	"""
-	Set Crab spectrum based on MAGIC observations
-	(Albert et al. 2008, ApJ, 674, 1037)
-
-	Keywords:
-	 flux - Source flux in Crab units
-	"""
-	# Set parameters
-	spectrum = GModelSpectralPlaw(flux, -2.48)
-	spectrum["Prefactor"].scale(5.7e-16)
-	spectrum["PivotEnergy"].value(0.3)
-	spectrum["PivotEnergy"].scale(1.0e6)
-	
-	# Return spectrum
-	return spectrum
-
-
-# ========================= #
-# Set any point-like source #
-# ========================= #
-def any_pointlike(name, l, b, flux=1.0, index=-2.48, fitpos=True, fitidx=True):
-	"""
-	Returns a single point-source with power-law spectrum.
-	The source flux can be scaled in Crab units.
-
-	Parameters:
-	 name   - Unique source name
-	 l      - Galactic longitude of source location [deg]
-	 b      - Galactic latitude of source location [deg]
-	Keywords:
-	 flux   - Source flux in Crab units
-	 fitpos - Specifies if position should be fitted or not
-	 fitidx - Specifies if index should be fitted or not
-	"""
-	# Set source location
-	location = GSkyDir()
-	location.lb_deg(l, b)
-	
-	
-	# Set source spatial model
-	spatial = GModelSpatialPtsrc(location)
-	
-	# Set source spectral model
-	spectrum = GModelSpectralPlaw(flux, index)
-	spectrum["Prefactor"].scale(5.7e-16)
-	spectrum["PivotEnergy"].value(0.3)
-	spectrum["PivotEnergy"].scale(1.0e6)
-	
-	# Set fit properties
-	if fitpos:
-		spatial[0].free()
-		spatial[1].free()
-	else:
-		spatial[0].fix()
-		spatial[1].fix()
-	
-	if fitidx:
-		spectrum["Index"].free()
-	else:
-		spectrum["Index"].fix()	
-
-	# Assign spatial and spectral models to source object
-	source  = GModelPointSource(spatial, spectrum)
-	
-	# Set source name
-	source.name(name)
-	
-	# Return source
-	return source
-
-
-# =============================== #
-# Setup single observation survey #
-# =============================== #
-def survey_single(caldb, irf, lpnt=0.0, bpnt=0.0):
-	"""
-	This is an example of how to create a pointing strategy. Here, we
-	only have a single CTA pointing, so this is a very basic pointing
-	strategy.
-
-	Parameters:
-	 caldb - Calibration database
-	 irf   - Response function
-	 lpnt  - Galactic longitude of pointing [deg]
-	 bpnt  - Galactic latitude of pointing [deg]
-	"""
-	# Allocate observation container
-	obs = GObservations()
-	
-	# Set single pointing at galactic centre
-	pntdir = GSkyDir()
-	pntdir.lb_deg(lpnt, bpnt)
-	run = set_one_obs(pntdir, caldb=caldb, irf=irf)
-	obs.append(run)
-	
-	# Return observation container
-	return obs
-
-
-# =========================== #
-# Setup Galactic plane survey #
-# =========================== #
-def survey_gplane(caldb, irf, bpnt=0.0, lrange=10, lstep=2):
-	"""
-	Creates a single observation survey for test purposes.
-	
-	Keywords:
-	 bpnt   - Latitude value for scan [deg]
-	 lrange - Longitude range (integer deg)
-	 lstep  - Longitude step size (integer deg)
-	"""
-	# Allocate observation container
-	obs = GObservations()
-	
-	# Loop over longitudes
-	for l in range(-lrange,lrange+lstep,lstep):
-		
-		# Set pointing
-		pntdir = GSkyDir()
-		pntdir.lb_deg(l, bpnt)
-		run = set_one_obs(pntdir, caldb=caldb, irf=irf)
-		obs.append(run)
-	
-	# Return observation container
-	return obs
-
-
-# =========================== #
-# Setup Galactic plane survey #
-# =========================== #
-def survey_square(caldb, irf, lrange=2.0, lstep=2.0, duration=1800.0, \
-                  emin=0.1, emax=100.0):
-	"""
-	Creates a single observation survey over a square grid.
-	For the moment, the grid is centred on (l,b)=(0,0)
-	
-	Arguments:
-	 lrange - Longitude/latitude range (float deg)
-	 lstep  - Longitude/latitude step size (float deg)
-	 duration/emin/emax - See set_one_obs function
-	"""
-	# Allocate observation container
-	obs = GObservations()
-	
-	# Compute number of points along each axis
-	num_pnt= int(round(2.0*lrange/lstep)+1.0)
-	
-	# Loop over longitudes and latitudes
-	for i in range(0,num_pnt):
-		for j in range(0,num_pnt):
-		
-			# Set pointing
-			l= -lrange+i*lstep
-			b= -lrange+j*lstep
-			pntdir = GSkyDir()
-			pntdir.lb_deg(l, b)
-			run = set_one_obs(pntdir, caldb=caldb, irf=irf, duration=duration, \
-			                  emin=emin, emax=emax)
-			obs.append(run)
-	
-	# Return observation container
-	return obs
-
-
-# =========================== #
-# Setup Galactic plane survey #
-# =========================== #
-def survey_galplane(caldb, irf, lmin=-2.0, lstep=2.0, nstep=3, duration=1800.0, \
-                    emin=0.1, emax=100.0):
-	"""
-	Creates a single observation survey along the galactic plane
-	
-	Arguments:
-	 lmin   - Starting longitude(float deg)
-	 lstep  - Longitude step size (float deg)
-	 nstep  - Number of steps/pointings
-	 duration/emin/emax - See set_one_obs function
-	"""
-	# Allocate observation container
-	obs = GObservations()
-		
-	# Loop over longitudes
-	for i in range(0,nstep):
-		
-		# Set pointing
-		l= lmin+i*lstep
-		b= 0.0
-		pntdir = GSkyDir()
-		pntdir.lb_deg(l, b)
-		run = set_one_obs(pntdir, caldb=caldb, irf=irf, duration=duration, \
-		                  emin=emin, emax=emax)
-		obs.append(run)
-	
-	# Return observation container
-	return obs
-
-# ===================================== #
-# Setup set of point source Crab models #
-# ===================================== #
-def add_point_sources(obs):
-	"""
-	Add point-source model made of Crab-like sources.
-	"""
-	# Add point-source Crabs
-	obs = add_source_model(obs, crab_like("Crab", 0.0, 0.0))
-	obs = add_source_model(obs, crab_like("Crab 1deg off", 1.0, 0.0))
-	obs = add_source_model(obs, crab_like("Crab 2deg off", 2.0, 0.0))
-	obs = add_source_model(obs, crab_like("Crab 3deg off", 3.0, 0.0))
-	obs = add_source_model(obs, crab_like("Crab 4deg off", 4.0, 0.0))
-	obs = add_source_model(obs, crab_like("Crab 5deg off", 5.0, 0.0))
-	
-	# Return
-	return obs
-
-
-# ================= #
-# Setup disk models #
-# ================= #
-def add_disk_sources(obs):
-	"""
-	Add disk-source model made of Crab-like sources.
-	"""
-	# Add disk Crabs
-	obs = add_source_model(obs, crab_like("Disk 0deg off",  0.0, 0.0, type="disk", radius=0.3))
-	obs = add_source_model(obs, crab_like("Disk 1deg off", -1.0, 0.0, type="disk", radius=0.3))
-	obs = add_source_model(obs, crab_like("Disk 2deg off", -2.0, 0.0, type="disk", radius=0.3))
-	obs = add_source_model(obs, crab_like("Disk 3deg off", -3.0, 0.0, type="disk", radius=0.3))
-	#obs = add_source_model(obs, crab_like("Disk 4deg off", -4.0, 0.0, type="disk", radius=0.3))
-	#obs = add_source_model(obs, crab_like("Disk 5deg off", -5.0, 0.0, type="disk", radius=0.3))
-	
-	# Return
-	return obs
-
-
-# ================== #
-# Setup Gauss models #
-# ================== #
-def add_gauss_sources(obs):
-	"""
-	Add Gauss-source model made of Crab-like sources.
-	"""
-	# Add Gauss Crabs
-	obs = add_source_model(obs, crab_like("Gauss 0deg off",  0.0, 0.0, type="gauss", sigma=0.3))
-	obs = add_source_model(obs, crab_like("Gauss 1deg off", -1.0, 0.0, type="gauss", sigma=0.3))
-	obs = add_source_model(obs, crab_like("Gauss 2deg off", -2.0, 0.0, type="gauss", sigma=0.3))
-	obs = add_source_model(obs, crab_like("Gauss 3deg off", -3.0, 0.0, type="gauss", sigma=0.3))
-	#obs = add_source_model(obs, crab_like("Gauss 4deg off", -4.0, 0.0, type="gauss", sigma=0.3))
-	#obs = add_source_model(obs, crab_like("Gauss 5deg off", -5.0, 0.0, type="gauss", sigma=0.3))
-
-	# Return
-	return obs
-
-
-# ================== #
-# Setup Shell models #
-# ================== #
-def add_shell_sources(obs):
-	"""
-	Add shell-source model made of Crab-like sources.
-	"""
-	# Add Shell Crabs
-	obs = add_source_model(obs, crab_like("Shell 0deg off",  0.0, 0.0, type="shell", radius=0.3, width=0.1))
-	obs = add_source_model(obs, crab_like("Shell 1deg off", -1.0, 0.0, type="shell", radius=0.3, width=0.1))
-	obs = add_source_model(obs, crab_like("Shell 2deg off", -2.0, 0.0, type="shell", radius=0.3, width=0.1))
-	#obs = add_source_model(obs, crab_like("Shell 3deg off", -3.0, 0.0, type="shell", radius=0.3, width=0.1))
-	#obs = add_source_model(obs, crab_like("Shell 4deg off", -4.0, 0.0, type="shell", radius=0.3, width=0.1))
-	#obs = add_source_model(obs, crab_like("Shell 5deg off", -5.0, 0.0, type="shell", radius=0.3, width=0.1))
-	
-	# Return
-	return obs
-
-
-# ==================== #
-# Setup big disk model #
-# ==================== #
-def add_big_disk_source(obs):
-	"""
-	Add big disk-source model.
-	"""
-	# Add one big offset disk Crab
-	obs = add_source_model(obs, crab_like("Big Disk", 1.0, 1.0, type="disk", radius=1.0))
-	
-	# Return
-	return obs
-
-
-# ===================== #
-# Setup big Gauss model #
-# ===================== #
-def add_big_gauss_source(obs):
-	"""
-	Add big gauss-source model.
-	"""
-	# Add one big offset Gauss Crab
-	obs = add_source_model(obs, crab_like("Big Gauss", -1.0, 1.0, type="gauss", sigma=1.0))
-	
-	# Return
-	return obs
-
-
-# ===================== #
-# Setup big shell model #
-# ===================== #
-def add_big_shell_source(obs):
-	"""
-	Add big shell-source model.
-	"""
-	# Add one big offset Shell Crab
-	obs = add_source_model(obs, crab_like("Big Shell", -1.0, -1.0, type="shell", radius=1.0, width=0.1))
-	
-	# Return
-	return obs
-
-
-# ================================================= #
-# Setup set of point source for the survey analysis #
-# ================================================= #
-def add_survey_sources(obs):
-	"""
-	Add point-source model made of Crab-like sources.
-	"""
-	# Add point-source Crabs
-	obs = add_source_model(obs, crab_like("Source 1", 0.0, 0.0, flux=0.1, type="point"))
-	obs = add_source_model(obs, crab_like("Source 2", 1.0, 0.0, flux=0.2, type="point"))
-	obs = add_source_model(obs, crab_like("Source 3", -1.0, 0.0, flux=0.5, type="point"))
-	obs = add_source_model(obs, crab_like("Source 4", 0.0, 1.0, flux=1.0, type="point"))
-	obs = add_source_model(obs, crab_like("Source 5", 0.0, -1.0, flux=2.0, type="point"))
-	obs = add_source_model(obs, crab_like("Source 6", 0.0, 4.0, flux=5.0, type="point"))
-	
-	# Return
-	return obs
-
-
-# ================================================= #
-# Setup set of point source for the survey analysis #
-# ================================================= #
-def add_random_sources(model):
-	"""
-	Add point-sources uniformly distributed over the sky, with a parameterised distribution in flux.
-	
-	Arguments
-	- model: a source model container to hold the source model over the loop
-	
-	Notes
-	- Contrary to other add_source functions, this one works on a model container and not on an observation container
-	- This is because we need to reuse the same random source model in a loop over pointing strategies 
-	"""
-	# Define source population characteristics
-	flux_min=0.001
-	flux_max=10.0
-	flux_index=-2.0
-	field=4.0
-	l_min=0.0-0.5*field
-	b_min=0.0-0.5*field
-	num_sources=4
-	
-	# Loop over sources to be generated
-	for i in range(0,num_sources):
-	
-		# Get random flux
-		flux=math.log10(flux_min)+(math.log10(flux_max)-math.log10(flux_min))*random.random()
-		flux=math.pow(10.0,flux)
-	
-		# Get random longitude/latitude
-		l=l_min+field*random.random()
-		b=b_min+field*random.random()
-	
-		# Add point-source Crabs
-		sourcename="Source "+str(i)
-		model.append(crab_like(sourcename, l, b, flux=flux, type="point"))
-	
-	# Return
-	return model
-
-
-# ================================================= #
-# Setup a test point source for the survey analysis #
-# ================================================= #
-def add_test_sources(models, l=0.0, b=0.0, flux=1.0, index=-2.5):
-	"""
-	Add a test point-source with specified position, flux, and spectral index
-	
-	Arguments
-	- l: longitude
-	- b: latitude
-	- flux: flux in Crab units
-	- index: spectral index
-	"""
-	
-	# Set source name
-	sourcename="Test"
-	
-	# Add it to container
-	models = add_source_model(models, any_pointlike(sourcename, l, b, \
-	                          flux=flux, index=index, fitpos=False, fitidx=False))
-	
-	# Return
-	return models
-
-
-#==============================#
-# Modified routine entry point #
-#==============================#
-if __name__ == '__main__':
-	"""
-	CTA survey simulation and analysis script.
-	
-	Notes:
-	- Based on the initial script
-	- Added functions: survey_square, add_survey_sources, add_random_sources
-	- Added import: math, random
-	
-	"""
-	# Set job parameters
-	irf          = "kb_E_50h_v3"     # IRF
-	survey_time  = 50.0*3600.0       # Total survey time
-	pnt_step     = 1.0               # Spacing between pointings
-	pnt_mintime  = 3600.0            # Minimum duration of a pointing
-	pnt_fov      = 1.0               # Typical FoV size (useful to know where to probe sensitivity)
-	pnt_maxnum   = 1                 # Maximum number of pointings
-	emin         = 0.1               # minimum energy (TeV)
-	emax         = 100.0             # maximum energy (TeV)
-	#emin         = 1.0               # minimum energy (TeV)
-	#emax         = 5.0               # maximum energy (TeV)
-	nbins        = 20                # number of logarithmic energy bins
-	test_thres   = 25.0              # Reference TS
-	index        = -3.0              # Spectral index
-	
-	# Initialise response database
-	caldb = "/usr/local/gamma/share/caldb/cta"	
-	
-	# Initialise flags
-	need_help = False
-	
-	# Test for command line arguments
-	if (len(sys.argv) > 1):
-		surveyrange= float(sys.argv[1])
-		
-	if (len(sys.argv) > 2):
-		surveystep= float(sys.argv[2])
-		
-	if (len(sys.argv) > 3):
-		irf=sys.argv[3]			
-
-	# Print help if needed and exit
-	if need_help:
-		print "Usage: example_survey.py [OPTIONS]"
-		print "      galscan  Simulate Galactic plane scan"
-		print "      extended Simulate also extended sources"
-		print "     -h        Display this usage message"
-		sys.exit()
-	
-	# Dump header
-	print "***********************"
-	print "* Simulate CTA survey *"
-	print "***********************"
-	
-	# Remove any existing result files
-	list = [glob.glob("*.fits"), glob.glob("*.log"), glob.glob("*.xml")]
-	for files in list:
-		for file in files:
-			os.remove(file)
-	
-	# Set number of observations
-	first        = True
-	results_file = 'sensitivity.dat'
-	for i in range(1,pnt_maxnum+1):
-	
-		# Initialise models
-		bkg_model  = GModels()
-		full_model = GModels()
-
-		# Setup models
-		bkg_model  = add_background_model(bkg_model)
-		full_model = add_background_model(full_model)
-		full_model = add_test_sources(full_model, 0.0, 0.0, flux=1.0, index=index)
-
-		# Compute duration of pointings and starting longitude
-		pnt_duration = survey_time/float(i)
-		pnt_lmin     = 0.0-float(i-1)*pnt_step/2.0
-
-		# Setup observations for survey 
-		survey = survey_galplane(caldb, irf, lmin=pnt_lmin, lstep=pnt_step, \
-							     nstep=i, duration=pnt_duration, \
-							     emin=emin, emax=emax)
-		
-		print ""
-		print "Simulating an array of "+str(i)+" observations along the plane"
-	
-		# Look for smallest flux for detection
-		test_num   = 0
-		test_max   = 50
-		test_flux  = 0.001
-		
-		# Loop
-		flux_value = []
-		while True:
-		
-			# Update test counter
-			test_num = test_num + 1
-			
-			# Set test flux
-			full_model[1]['Prefactor'].value(test_flux)
-			survey.models(full_model)
-			
-			# Simulate events
-			obs = sim_obs(survey, nbins=nbins, seed=test_num)
-		
-			# Determine number of events in simulation
-			nevents = 0.0
-			for x in obs:
-				nevents += x.events().number()
-
-			# Fit background only
-			obs.models(bkg_model)
-			like = fit_obs(obs,log=False)
-			
-			# Store results
-			LogL_bgm  = like.opt().value()
-			Pre_bgm   = like.obs().models()[0]['Prefactor'].value()
-			ePre_bgm  = like.obs().models()[0]['Prefactor'].error()
-			Inx_bgm   = like.obs().models()[0]['Index'].value()
-			eInx_bgm  = like.obs().models()[0]['Index'].error()
-			npred_bgm = like.obs().npred()
-
-			# Fit background and test source
-			obs.models(full_model)
-			like = fit_obs(obs,log=False)
-
-			# Store results
-			LogL_all  = like.opt().value()
-			test_ts   = 2.0*(LogL_bgm-LogL_all)
-			Pre_all   = like.obs().models()[0]['Prefactor'].value()
-			ePre_all  = like.obs().models()[0]['Prefactor'].error()
-			Inx_all   = like.obs().models()[0]['Index'].value()
-			eInx_all  = like.obs().models()[0]['Index'].error()
-			SPre_all  = like.obs().models()[1]['Prefactor'].value()
-			eSPre_all = like.obs().models()[1]['Prefactor'].error()
-			SInx_all  = like.obs().models()[1]['Index'].value()
-			eSInx_all = like.obs().models()[1]['Index'].error()
-			npred_all = like.obs().npred()
-			if test_ts > 0:
-				flux = math.sqrt(test_thres/test_ts)*SPre_all
-			else:
-				flux = 0.0
-			flux_value.append(flux)
-			
-			# Compute sliding average
-			flux = 0.0
-			num  = 0.0
-			for k in range(3):
-				inx = test_num - k - 1
-				if inx >= 0:
-					flux += flux_value[inx]
-					num  += 1.0
-			flux /= num
-			
-			# Print results
-			print "TS=%9.2f %8.5f lnL(BGD)=%8.1f lnL(ALL)=%8.1f #%5d" \
-			      "  BGD: #%8.2f %5.2f+/-%4.2f %5.2f+/-%5.3f" \
-			      "  ALL: #%8.2f %5.2f+/-%4.2f %5.2f+/-%5.3f" \
-				  "  %8.5f+/-%7.5f %5.2f+/-%5.3f  Flux=%8.5f" % \
-				  (test_ts, test_flux, LogL_bgm, LogL_all, nevents, \
-				   npred_bgm, Pre_bgm, ePre_bgm, Inx_bgm, eInx_bgm, \
-				   npred_all, Pre_all, ePre_all, Inx_all, eInx_all, \
-				   SPre_all, eSPre_all, SInx_all, eSInx_all, \
-				   flux)
-
-			# Compare average flux to last average
-			if test_num > 3:
-				ratio = flux/test_flux
-				if ratio >= 0.99 and ratio <= 1.01:
-					print "Converged ("+str(ratio)+")"
-					break
-			
-			# Use average for next iteration
-			test_flux = flux
-			
-			# Exit loop if number of trials exhausted
-			if (test_num >= test_max):
-				print "Test ended after "+str(test_max)+" iterations."				
-				break
-
-		# Print results
-		print "Sensitivity of "+str(i)+" observations: "+str(flux*1000.0)+" mCrab"
-		
-		# Write to CSV file
-		result                 = {}
-		colnames               = ['emin', 'emax', 'observations', 'sensitivity']
-		result['emin']         = emin
-		result['emax']         = emax
-		result['observations'] = i
-		result['sensitivity']  = flux
-		if first:
-			f      = open(results_file, 'w')
-			writer = csv.DictWriter(f, colnames)
-			writer.writerow(dict((_,_) for _ in colnames))
-			first = False
-		else:
-			f = open(results_file, 'a')
-		writer = csv.DictWriter(f, colnames)
-		writer.writerow(result)
-		f.close()
-		
-		# Delete some objects
-		del obs
-		del like
-
-