diff --git a/doc/html/about.html b/doc/html/about.html index 8a6612f..d06ee21 100644 --- a/doc/html/about.html +++ b/doc/html/about.html @@ -1,43 +1,31 @@ - - - - - About - - - + +About + - -

About

-

ctatools are a set of ftools-like executables needed for the scientific analysis of Cherenkov Telescope Array data. ctatools are based on GammaLib, a versatile toolbox for the high-level analysis of astronomical gamma-ray data.

-
-

ctatools are implemented in C++ and are fully scriptable using the Python scripting language.

-
-

The ctatools development is led by the Insitut de Recherche en Astrophysique et Planétologie (IRAP), a mixed CNRS / Université Paul Sabatier laboratory in Toulouse, France.

-
- -
- - - +
+

Last updated by: Jürgen +Knödlseder 9 July +2011 +

+ \ No newline at end of file diff --git a/doc/html/documentation.html b/doc/html/documentation.html index 6cca745..0c821f2 100644 --- a/doc/html/documentation.html +++ b/doc/html/documentation.html @@ -2,7 +2,8 @@ Documentation - + +

Documentation


@@ -17,8 +18,8 @@ references
-

Last updated by: Jürgen Knödlseder 8 March +

Last updated by: Jürgen +Knödlseder 8 March 2011

-
\ No newline at end of file diff --git a/doc/html/download.html b/doc/html/download.html index 771c471..cf1ddbf 100644 --- a/doc/html/download.html +++ b/doc/html/download.html @@ -7,8 +7,8 @@

Download

-The latest ctatools release is ctatools-00-02-01 -(February 24, 2011).

+The latest ctatools release is ctatools-00-02-03 +(July 9, 2011).



Latest release

@@ -19,14 +19,36 @@ and gammalib versions.

ctatools -00-02-01 +gammalib +00-02-03 +00-04-09 + + + +
+
+

Older releases

+

At +this early stage of the project there is a strict link between ctatools +and gammalib versions.

+ + + + + + +
ctatools gammalib
00-02-01 00-04-07
-

-

+
+
+

Last updated by: Jürgen +Knödlseder 9 July +2011 +

\ No newline at end of file diff --git a/doc/html/home.html b/doc/html/home.html index ecd2791..88c7fa5 100644 --- a/doc/html/home.html +++ b/doc/html/home.html @@ -2,7 +2,8 @@ Home - + +

ctatools

ctatools @@ -32,7 +33,8 @@ license version 3.

Simulation of galactic plane scan, composed of 10 half-hour observations, spaced by -2° in Galactic longitude. A single point source with Crab spectrum was +2° in Galactic longitude. A single point source with Crab +spectrum was simulated at the Galactic centre. The top panel shows the model, the bottom panel the simulated data. @@ -40,4 +42,9 @@ bottom panel the simulated data.
- \ No newline at end of file +
+

Last updated by: Jürgen +Knödlseder 9 July +2011 +
+

\ No newline at end of file diff --git a/doc/html/installation.html b/doc/html/installation.html index deab98c..bdb3f94 100644 --- a/doc/html/installation.html +++ b/doc/html/installation.html @@ -1,47 +1,32 @@ +Installation - - - - - Installation - + -

Installation

-

Step 1: Install GammaLib

-

Step 2: Setup environment

-

Step 3: Install ctatools

-

Known Problems

-

Getting Help

-
-

Note: These installation instructions apply to -ctatools-00-01-00 or later. +ctatools-00-02-03 or later.

-
-

Step 1: Install GammaLib

-

ctatools depends on GammaLib and thus GammaLib needs to be installed on your system prior to installing ctatools. If you do not have GammaLib @@ -51,14 +36,10 @@ and follow the GammaLib installation instructions on http://gammalib.sourceforge.net/.
-
-

-

Step 2: Setup environment

-

Before using GammaLib (and ctatools use GammaLib) you have to setup some environment variables. @@ -72,65 +53,50 @@ or $HOME/.profile -

export GAMMALIB=/usr/local/gamma
- source $GAMMALIB/bin/gammalib-init.sh

-

If you use C shell or a variant then add the following to your .cshrc or .tcshrc script:

-

setenv GAMMALIB /usr/local/gamma
- source $GAMMALIB/bin/gammalib-init.csh

-
-
-

Step 3: Install ctatools

-

After downloading the ctatools tarball, save it in an appropriate location (for example /usr/local/gamma/src), and type

-

-> tar xvfz ctatools-00-01-00.tar.gz +> tar xvfz ctatools-00-02-03.tar.gz

-

Step in the created directory using

-

> cd ctatools

-

and build and install ctatools by typing

-

> ./configure
- > make
- +> make check
> make install

-

at the operating system prompt. The ./configure command customizes the Makefiles for the particular system, the make -command compiles the source files and builds the executables, and +command compiles the source files and builds the executables, the the make +check command performs a system test, and the make install command installs the executables in the bin directory. @@ -141,9 +107,7 @@ configuration script in the current directory is run and not some other system-wide configuration script. 

-
-

By default, the install directory is set to /usr/local/gamma. @@ -152,54 +116,58 @@ argument should be given, for example:

-

> ./configure --prefix=/usr/local

-

A full list of configuration options can be found using

-

> ./configure --help

-
-

Known Problems

- +

+Mac OS X +
The Python development package is not installed as default on Mac +OS X, and consequently, the Python.h header file is missing that is +needed to compile in the Python bindings. The configure script should +recognise this fact and adjust the build procedure accordingly, but you +will not be able to use ctatools from Python. So better install the +Python development package before installing ctatools.

It +was also reported that adding of export +MACOSX_DEPLOYMENT_TARGET=10.6 to the .bashrc file was necessary one +some Mac OS X 10.6 installations to make ctatools compile.
+
+

Solaris
- ctatools has been compiled successfully on Solaris 2.10 using the Sun Studio compiler. However, GammaLib symbols are not globally exported due to a strage behaviour of the Sun Studio compiler. This prevents for example GammaLib library from catching its own exceptions and from registering models. Consequently, many functionnalities will not work.

-
-

Using gcc (version 3.4.3), ctatools and GammaLib works correctly on Solaris 2.10, yet loading ctatools or GammaLib as a Python module fails.
-
-

-
-

Getting Help

-

Any questions, bug reports, or suggested enhancements related to ctatools should be submitted to knodlseder@cesr.fr.

- +
+
+

Last updated by: Jürgen +Knödlseder 9 July +2011 +

\ No newline at end of file diff --git a/doc/html/quickstart.html b/doc/html/quickstart.html index 9735a7d..cc87584 100644 --- a/doc/html/quickstart.html +++ b/doc/html/quickstart.html @@ -1,58 +1,35 @@ - - - - - Getting Started - - - + +Getting Started + - -

Getting started

-

First steps with ctatools

-

This page gives provides a step-by-step description of the CTA data analysis procedure implemented in ctatools. In this example we will simulate data for the Crab nebula, observed on-axis, as a single source in the CTA field of view.

-
-

The example consists of the following analysis steps:

-

Simulating CTA data

-

Binning CTA data

-

Fitting CTA data

-

Doing an unbinned analysis

-
-

And please read also:

-

Some final remarks

-

Getting Help

-
-
-

Simulating CTA data

-

CTA data are simulated by the executable ctobssim. To start the executable, type ctobssim @@ -62,35 +39,21 @@ work on a system that has been installed in the default directory > ctobssim
- Model [test/data/crab_alone.xml] /usr/local/gamma/share/models/crab.xml
- Output event data file [events.fits]
- Calibration database [test/irf] /usr/local/gamma/share/caldb/cta
- Instrument response function [kb_E_50h_v3]
- RA for ROI centre (degrees) (0-360) [83.63]
- Dec for ROI centre (degrees) (-90-90) [22.01]
- Radius of ROI (degrees) (0-180) [10.0]
- Start time (MET in s) (0) [0.0]
- End time (MET in s) (0) [1800.0]
- Lower energy limit (TeV) (0) [0.1]
- Upper energy limit (TeV) (0) [100.0]
-

-

Each line represents a query for one parameter. The line starts with a short description of the parameter, followed by the default parameter value @@ -98,9 +61,7 @@ proposed by ctobssim[ ]. If no parameter is entered (which is the case for the majority of parameters shown here), the default parameter will be used.

-
-

The CTA instrument properties (effective area, PSF width) are taken for the moment from Konrad Bernlöhrs sensitivity files which are @@ -108,9 +69,7 @@ stored in /usr/local/g To test another CTA configuration you may adapt the instrument response function name accordingly (see the final remarks).

-
-

Events are simulated based on the instrument properties and based on a source and background model. Only events that fall within the @@ -119,97 +78,68 @@ position in Right Ascension and Declination (in degrees), will be stored in the output event data file. The duration of the simulation is taken here to 30 minutes (or 1800 seconds). Events are simulated for energies between 0.1 and 100 TeV.

-
-

The source and background model is defined by the XML file /usr/local/gamma/share/models/crab.xml:

-

<?xml version="1.0" standalone="no"?>
- <source_library title="source library">
-   <source name="MAGIC Crab (Albert et al. 2008, ApJ, 674, 1037)" type="PointSource">
-     <spectrum type="PowerLaw">
-        <parameter name="Prefactor" scale="1e-16" value="5.7"  min="1e-07" max="1000.0" free="1"/>
-        <parameter name="Index"     scale="-1"    value="2.48" min="0.0"   max="+5.0"   free="1"/>
-        <parameter name="Scale"     scale="1e6"   value="0.3"  min="0.01"  max="1000.0" free="0"/>
-     </spectrum>
-     <spatialModel type="SkyDirFunction">
-       <parameter name="RA"  scale="1.0" value="83.6331" min="-360" max="360" free="0"/>
-       <parameter name="DEC" scale="1.0" value="22.0145" min="-90"  max="90"  free="0"/>
-     </spatialModel>
-   </source>
-   <source name="Background" type="RadialAcceptance" instrument="CTA">
-     <spectrum type="PowerLaw">
-        <parameter name="Prefactor" scale="1e-6" value="61.8" min="0.0"  max="1000.0" free="1"/>
-        <parameter name="Index"     scale="-1"   value="1.85" min="0.0"  max="+5.0"   free="1"/>
-        <parameter name="Scale"     scale="1e6"  value="1.0"  min="0.01" max="1000.0" free="0"/>
-     </spectrum>
-     <radialModel type="Gaussian">
-        <parameter name="Sigma" scale="1.0" value="3.0" min="0.01" max="10.0" free="1"/>
-     </radialModel>
-   </source>
- </source_library>

-

The model consists of a source library that contains 2 "sources": the Crab nebula and an instrumental background model.

-
-

The Crab nebula is modelled by a factorized sky model that has a spectral and a spatial component (tags <spectrum> @@ -236,22 +166,16 @@ The min, and free attributes are not relevant here for the simulations, but they will be important for the model fitting later.

-
-

The spectral intensity I(E) (in units of photons/cm2/s/MeV) of the power law is given by 

-

I(E) = Prefactor * (E/Scale)^Index

-

where the E and Scale are given in MeV.

-
-

The instrumental background of CTA is modelled by a factorized data model that has a spectral and a radial component (tags <spectrum> @@ -265,9 +189,7 @@ with offset angle squared, direction) which is modelled here by a Gaussian. The only parameter of the radial component is the width of the Gaussian Sigma, which is here set to 3 degrees squared.

-
-

ctobssim has a couple of hidden parameters, the most important one being certainly seed. @@ -277,11 +199,8 @@ generator, and changing this parameter will allow to generate statistically independent Monte Carlo samples of CTA event data. To use for example a seed value of 41 one should type:

-

> ctobssim seed=41
-

-

ctobssim will write 2 files in the working directory: events.fits @@ -295,64 +214,38 @@ that holds the events (one row per event), and a binary table named -
-

The second file produced by ctobssim is a human readable log file that contains information about the job execution. As example, the last lines from this file are shown here:

-

2011-01-31T23:50:39: +==================+
- 2011-01-31T23:50:39: | Simulate photons |
- 2011-01-31T23:50:39: +==================+
- 2011-01-31T23:50:39:  Simulated photons .........: 33943
- 2011-01-31T23:50:39:  Simulation area ...........: 3.2e+10 cm2
- 2011-01-31T23:50:39:  Simulation cone ...........: RA=83.63 deg, Dec=22.01deg, r=10 deg
- 2011-01-31T23:50:39:  Time interval .............: 0 s - 1800 s
- 2011-01-31T23:50:39:  Energy range ..............: 100 GeV - 100 TeV
- 2011-01-31T23:50:39:  Random number seed ........: 1
- 2011-01-31T23:50:39:
- 2011-01-31T23:50:39: +=================+
- 2011-01-31T23:50:39: | Simulate events |
- 2011-01-31T23:50:39: +=================+
- 2011-01-31T23:50:39:  MC source events ..........: 649
- 2011-01-31T23:50:39:  MC background events ......: 3407
- 2011-01-31T23:50:39:
- 2011-01-31T23:50:39: +==========================+
- 2011-01-31T23:50:39: | Save events in FITS file |
- 2011-01-31T23:50:39: +==========================+
- 2011-01-31T23:50:39:
- 2011-01-31T23:50:39: Application "ctobssim" terminated after consuming 14 seconds of CPU time.
-
-

-

Each line starts with the UTC time at which the line has been written. In this @@ -360,54 +253,34 @@ run, 33943 Crab photons have been thrown over an area of 3.2 square kilometres during a time interval of 1800 seconds. 649 of these photons have been registered by CTA as events. In the same time interval, 3407 background events have been registred by CTA.

-
-
-

Binning CTA data

-

As next analysis step the data are binned in a counts map using the executable ctbin. A counts map is a 3 dimensional data cube, spanned by Right Ascension (or Galactic longitude), Declination (or Galactic latitude), and the logarithm (base 10) of energy.

-
-

ctbin is executed by typing:

-

> ctbin
- Event data file name [test/data/crab_events.fits.gz] events.fits
- Output file name [cntmap.fits]
- Start value for first energy bin in TeV [0.1]
- Stop value for last energy bin in TeV [100.0]
- Number of energy bins [20]
- Projection method e.g. AIT|ARC|CAR|GLS|MER|NCP|SIN|STG|TAN [CAR]
- Coordinate system (CEL - celestial, GAL - galactic) (CEL|GAL) [CEL]
- First coordinate of image center in degrees (RA or galactic l) [83.63]
- Second coordinate of image center in degrees (DEC or galactic b) [22.01]
- Image scale (in degrees/pixel) [0.02]
- Size of the X axis in pixels [200]
- Size of the Y axis in pixels [200]

-

In this example we adjust the event data file name and accept all the remaining parameter defaults as they perfectly @@ -419,107 +292,73 @@ the cartesian projection is the only valid project available for the moment). The counts map has 200 x 200 spatial pixels of 0.02 x 0.02 degrees in size, hence it covers a total area of 4 x 4 degrees.

-
-

A set of 20 counts maps will be created, which are logarithmically spaced in energy, and which cover the energy range from 0.1 TeV to 100 TeV. In this example, the counts map will be saved as cntmap.fits in the working directory. -In addition to the counts map, that is stored as the primary image extension, the FITS +In addition to the counts map, that is stored as the primary image +extension, the FITS file also contains an extension named EBOUNDS that defines the energy boundaries that were used, and an extension GTI that defines the Good Time Intervals that have been used. The following -image shows the resulting FITS file. The EBOUNDS table has 20 rows, one for each energy bin, while the GTI table has jusr a single row, indicating the start and stop time of the simulated data.

+image shows the resulting FITS file. The EBOUNDS +table has 20 rows, one for each energy bin, while the GTI +table has jusr a single row, indicating the start and stop time of the +simulated data.


-
CTA counts map FITS file
-
-
-

An image of the first bin, covering the energy range 100 - 141 GeV, is shown below:

-
CTA counts map
-
-
-

For illustrating, the last few lines of the log file ctbin.log are shown below:

-

2011-02-01T09:28:05: +=========+
- 2011-02-01T09:28:05: | Binning |
- 2011-02-01T09:28:05: +=========+
- 2011-02-01T09:28:05:  Events in list ............: 4056
- 2011-02-01T09:28:05:  Events in map .............: 3683
- 2011-02-01T09:28:05:  Events outside map area ...: 373
- 2011-02-01T09:28:05:  Events outside energy bins : 0
- 2011-02-01T09:28:05:
- 2011-02-01T09:28:05: +============+
- 2011-02-01T09:28:05: | Counts map |
- 2011-02-01T09:28:05: +============+
- 2011-02-01T09:28:05: === GSkymap ===
- 2011-02-01T09:28:05:  Number of pixels ..........: 40000
- 2011-02-01T09:28:05:  Number of maps ............: 20
- 2011-02-01T09:28:05:  X axis dimension ..........: 200
- 2011-02-01T09:28:05:  Y axis dimension ..........: 200
- 2011-02-01T09:28:05: === GWcsCAR ===
- 2011-02-01T09:28:05:  Coordinate system .........: EQU
- 2011-02-01T09:28:05:  Reference coordinate ......: (83.63, 22.01) deg
- 2011-02-01T09:28:05:  Reference pixel ...........: (100.5, 100.5)
- 2011-02-01T09:28:05:  Increment at reference ....: (0.02, 0.02) deg
- 2011-02-01T09:28:05:  Coordinate of North Pole ..: (180, 0) deg
- 2011-02-01T09:28:05:  CD matrix .................: [0.02 0][0 0.02]
- 2011-02-01T09:28:05:  Inverse CD matrix .........: [50 -0][-0 50]
- 2011-02-01T09:28:05:  Coordinate of native pole .: (83.63, 112.01)
- 2011-02-01T09:28:05:
- 2011-02-01T09:28:05: Application "ctbin" terminated after consuming 10 seconds of CPU time.

-

From the 4056 events that have been simulated and stored in the events.fits file, 3683 lie within the map boundaries and are thus put into the @@ -527,14 +366,10 @@ resulting counts map. The counts map is stored in a cartesian projection in a World Coordinate System (WCS) compliant format.

-
-
-

Fitting CTA data

-

Now we are ready to fit the simulated data with a model. For simplicity we use in this example the same model that we used to simulate the data @@ -542,23 +377,15 @@ with ctobssim. Model fitting is done using the executable ctlike, and we do the fit by typing:

-

> ctlike
- Maximum likelihood method [BINNED]
- Calibration database [test/irf] /usr/local/gamma/share/caldb/cta
- Instrument response function [kb_E_50h_v3]
- Source model [test/data/crab.xml] /usr/local/gamma/share/models/crab.xml
- Source model output file [crab_results.xml]
- Counts map [test/data/crab_cntmap.fits.gz] cntmap.fits

-

Fitting of the data is done in BINNED mode, which means that the events have been binned into a counts map @@ -570,9 +397,7 @@ log-likelihood is computed directly by summing over all events. We will explore the UNBINNED mode later.

-
-

One of the parameters given to ctlike is a source model output file (we specified crab_results.xml @@ -582,79 +407,54 @@ addition, the statistical uncertainties are added for each fitted parameter using the attribute error. Below we show the XML result file that has been produced by the run:

-

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
- <source_library title="source library">
-   <source name="MAGIC Crab (Albert et al. 2008, ApJ, 674, 1037)" type="DiffuseSource">
-     <spectrum type="PowerLaw">
-       <parameter name="Prefactor" value="5.7765" error="0.243328" scale="1e-16" min="1e-07" max="1000" free="1" />
-       <parameter name="Index" value="2.49937" error="0.0330191" scale="-1" min="0" max="5" free="1" />
-       <parameter name="Scale" value="0.3" scale="1e+06" min="0.01" max="1000" free="0" />
-     </spectrum>
-     <spatialModel type="SkyDirFunction">
-       <parameter name="RA" value="83.6331" scale="1" min="-360" max="360" free="0" />
-       <parameter name="DEC" value="22.0145" scale="1" min="-90" max="90" free="0" />
-     </spatialModel>
-   </source>
-   <source name="Background" type="RadialAcceptance" instrument="CTA">
-     <spectrum type="PowerLaw">
-       <parameter name="Prefactor" value="61.7696" error="1.89829" scale="1e-06" min="0" max="1000" free="1" />
-       <parameter name="Index" value="1.87195" error="0.0166039" scale="-1" min="0" max="5" free="1" />
-       <parameter name="Scale" value="1" scale="1e+06" min="0.01" max="1000" free="0" />
-     </spectrum>
-     <radialModel type="Gaussian">
-       <parameter name="Sigma" value="3.00467" error="0.071261" scale="1" min="0.01" max="10" free="1" />
-     </radialModel>
-   </source>
- </source_library>

-

In this example, the Prefactor and Index @@ -663,147 +463,89 @@ of the spectral model for the Crab as well as the Sigma parameter of the radial acceptance model have been fitted (all parameters having the attribute free="1" -are fitted). One could -be tempted to try fitting also the location of the Crab point source, -yet this feature is not yet implemented. +are fitted).

-
-

To get more details about the model fitting one can inspect the log file. Below we show the last lines of the ctlike.log log file that has been produced by this run:

-

2011-02-01T09:53:17: +=================================+
- 2011-02-01T09:53:17: | Maximum likelihood optimisation |
- 2011-02-01T09:53:17: +=================================+
- 2011-02-01T09:53:20:  Initial iteration: func=18092.1, Lambda=0.001
- 2011-02-01T09:53:24:  Iteration 1: func=18090, Lambda=0.0001, delta=2.08792
- 2011-02-01T09:53:27:  Iteration 2: func=18090, Lambda=1e-05, delta=0.0021398
- 2011-02-01T09:53:30:  Iteration 3: func=18090, Lambda=1e-06, delta=4.80215e-06
- 2011-02-01T09:53:34:  Iteration 4: func=18090, Lambda=1e-07, delta=1.7495e-08
- 2011-02-01T09:53:37:
- 2011-02-01T09:53:37: +=========================================+
- 2011-02-01T09:53:37: | Maximum likelihood optimisation results |
- 2011-02-01T09:53:37: +=========================================+
- 2011-02-01T09:53:37: === GOptimizerLM ===
- 2011-02-01T09:53:37:  Optimized function value ..: 18090
- 2011-02-01T09:53:37:  Absolute precision ........: 1e-06
- 2011-02-01T09:53:37:  Optimization status .......: converged
- 2011-02-01T09:53:37:  Number of parameters ......: 11
- 2011-02-01T09:53:37:  Number of free parameters .: 5
- 2011-02-01T09:53:37:  Number of iterations ......: 4
- 2011-02-01T09:53:37:  Lambda ....................: 1e-07
- 2011-02-01T09:53:37:  Maximum log likelihood ....: -18090
- 2011-02-01T09:53:37:  Npred .....................: 3683
- 2011-02-01T09:53:37: === GModels ===
- 2011-02-01T09:53:37:  Number of models ..........: 2
- 2011-02-01T09:53:37:  Number of parameters ......: 11
- 2011-02-01T09:53:37: === GModelPointSource ===
- 2011-02-01T09:53:37:  Name ......................: MAGIC Crab (Albert et al. 2008, ApJ, 674, 1037)
- 2011-02-01T09:53:37:  Instruments ...............: all
- 2011-02-01T09:53:37:  Number of parameters ......: 6
- 2011-02-01T09:53:37:  Number of spatial par's ...: 2
- 2011-02-01T09:53:37:   RA .......................: 83.6331 [-360,360] deg (fixed,scale=1)
- 2011-02-01T09:53:37:   DEC ......................: 22.0145 [-90,90] deg (fixed,scale=1)
- 2011-02-01T09:53:37:  Number of spectral par's ..: 3
- 2011-02-01T09:53:37:   Prefactor ................: 5.7765e-16 +/- 2.43328e-17 [1e-23,1e-13] ph/cm2/s/MeV (free,scale=1e-16)
- 2011-02-01T09:53:37:   Index ....................: -2.49937 +/- 0.0330191 [-0,-5]  (free,scale=-1)
- 2011-02-01T09:53:37:   PivotEnergy ..............: 300000 [10000,1e+09] MeV (fixed,scale=1e+06)
- 2011-02-01T09:53:37:  Number of temporal par's ..: 1
- 2011-02-01T09:53:37:   Constant .................: 1 (relative value) (fixed,scale=1)
- 2011-02-01T09:53:37: === GCTAModelRadialAcceptance ===
- 2011-02-01T09:53:37:  Name ......................: Background
- 2011-02-01T09:53:37:  Instruments ...............: CTA
- 2011-02-01T09:53:37:  Model type ................: "Gaussian" * "PowerLaw" * "Constant"
- 2011-02-01T09:53:37:  Number of parameters ......: 5
- 2011-02-01T09:53:37:  Number of radial par's ....: 1
- 2011-02-01T09:53:37:   Sigma ....................: 3.00467 +/- 0.071261 [0.01,10] deg2 (free,scale=1)
- 2011-02-01T09:53:37:  Number of spectral par's ..: 3
- 2011-02-01T09:53:37:   Prefactor ................: 6.17696e-05 +/- 1.89829e-06 [0,0.001] ph/cm2/s/MeV (free,scale=1e-06)
- 2011-02-01T09:53:37:   Index ....................: -1.87195 +/- 0.0166039 [-0,-5]  (free,scale=-1)
- 2011-02-01T09:53:37:   PivotEnergy ..............: 1e+06 [10000,1e+09] MeV (fixed,scale=1e+06)
- 2011-02-01T09:53:37:  Number of temporal par's ..: 1
- 2011-02-01T09:53:37:   Constant .................: 1 (relative value) (fixed,scale=1)
- 2011-02-01T09:53:37:
- 2011-02-01T09:53:37: Application "ctlike" terminated after consuming 41 seconds of CPU time.

-

The maximum likelihood optimizer required 4 iterations to converge. This is pretty fast, but recall that we used the same model file for the @@ -816,14 +558,10 @@ will see that the optimizer requires a couple of more iterations, but it should converge to the same solution (provided that the initial values are not too far of the best fitting values). 

-
-
-

Doing an unbinned analysis

-

As gamma-ray events are rare, the counts maps generated by ctbin will in general be sparse, having many empty pixels, in @@ -832,9 +570,7 @@ of working directly on the event list without binning the events in a counts map. We will see the benefit of such an analysis later once we re-run ctlike in unbinned mode.

-
-

For unbinned analysis we have first to define the data space region over which the analysis is done. This is similiar to the ctbin @@ -849,9 +585,7 @@ range is covered, and what time interval is spanned by the data. All this is done by the executable ctselect, which replaces the ctbin step in an unbinned analysis.

-
-

ctselect performs an event selection by choosing only events within a given @@ -863,31 +597,19 @@ called an acceptance cone. The following example shows how ctselect is invoked on the simulated test data:

-

> ctselect
- Input event data file [test/data/crab_events.fits.gz] events.fits
- Output event data file [selected_events.fits]
- RA for ROI centre (degrees) (0-360) [83.63]
- Dec for ROI centre (degrees) (-90-90) [22.01]
- Radius of ROI (degrees) (0-180) [3.0]
- Start time (MET in s) (0) [0.0]
- End time (MET in s) (0) [1800.0]
- Lower energy limit (TeV) (0) [0.1]
- Upper energy limit (TeV) (0) [100.0]
-

-

ctselect takes the input event list events.fits, performs an event selection, and writes the selected event into the @@ -901,66 +623,44 @@ by respecting the same syntax that has been implemented for Fermi-LAT. The following image is a screen dump of the data selection keywords that have been written to the EVENTS header in the file selected_events.fits:

-
-

 Data selection keywords

-
-

It is important for unbinned analysis that these data selection keywords exist. If they don't exist, ctlike will not execute in unbinned mode.

-
-

Below we show also for completeness the last few lines of the ctselect.log file. It gives information about the specific data selection that has been performed.

-

2011-02-01T19:58:34: +=================+
- 2011-02-01T19:58:34: | Event selection |
- 2011-02-01T19:58:34: +=================+
- 2011-02-01T19:58:34:  Time range ................: 0-1800
- 2011-02-01T19:58:34:  Energy range ..............: 0.1-100 TeV
- 2011-02-01T19:58:34:  Acceptance cone centre ....: RA=83.63, DEC=22.01 deg
- 2011-02-01T19:58:34:  Acceptance cone radius ....: 3 deg
- 2011-02-01T19:58:34:  cfitsio selection .........: TIME >= 0 && TIME <= 1800 && ENERGY >= 0.1 && ENERGY <= 100 && ANGSEP(83.63,
- 22.01,RA,DEC) <= 3
- 2011-02-01T19:58:34:  FITS filename .............: events.fits[EVENTS][TIME >= 0 && TIME <= 1800 && ENERGY >= 0.1 && ENERGY <=
- 100 && ANGSEP(83.63,22.01,RA,DEC) <= 3]
- 2011-02-01T19:58:34:
- 2011-02-01T19:58:34: Application "ctselect" terminated after consuming 10 seconds of CPU time.
-  
-

-

Now that the event selection has been performed, ctlike can be run in unbinned mode. To do this, you have to type UNBINNED @@ -972,24 +672,16 @@ that has been produced by ctlike in unbinned mode, type the following:

-

> ctlike
- Maximum likelihood method [BINNED] UNBINNED
- Calibration database [test/irf] /usr/local/gamma/share/caldb/cta
- Instrument response function [kb_E_50h_v3]
- Source model [test/data/crab.xml] /usr/local/gamma/share/models/crab.xml
- Source model output file [crab_results.xml]
- Event data file name [test/data/crab_events.fits.gz] selected_events.fits

-

You will recognise that ctlike runs much faster in unbinned mode compared to binned mode. This is @@ -1006,9 +698,7 @@ short event lists, unbinned mode is faster. Unbinned Below you see the corresponding output from the ctlike.log file. The fitted parameters are essentially identical to the ones found @@ -1018,151 +708,91 @@ different event sample that has been used for the analysis: while binned likelihood works on rectangular counts maps, unbinned likelihood works on circular event selection regions. It is thus not possible to select exactly the same events for both analyses!

-

2011-02-02T14:32:54: +=================================+
- 2011-02-02T14:32:54: | Maximum likelihood optimisation |
- 2011-02-02T14:32:54: +=================================+
- 2011-02-02T14:32:54:  Initial iteration: func=33730.9, Lambda=0.001
- 2011-02-02T14:32:54:  Iteration 1: func=33728.3, Lambda=0.0001, delta=2.56377
- 2011-02-02T14:32:54:  Iteration 2: func=33728.3, Lambda=1e-05, delta=0.00443209
- 2011-02-02T14:32:54:  Iteration 3: func=33728.3, Lambda=1e-06, delta=5.81336e-06
- 2011-02-02T14:32:54:  Iteration 4: func=33728.3, Lambda=1e-07, delta=1.31549e-08
- 2011-02-02T14:32:54:
- 2011-02-02T14:32:54: +=========================================+
- 2011-02-02T14:32:54: | Maximum likelihood optimisation results |
- 2011-02-02T14:32:54: +=========================================+
- 2011-02-02T14:32:54: === GOptimizerLM ===
- 2011-02-02T14:32:54:  Optimized function value ..: 33728.3
- 2011-02-02T14:32:54:  Absolute precision ........: 1e-06
- 2011-02-02T14:32:54:  Optimization status .......: converged
- 2011-02-02T14:32:54:  Number of parameters ......: 11
- 2011-02-02T14:32:54:  Number of free parameters .: 5
- 2011-02-02T14:32:54:  Number of iterations ......: 4
- 2011-02-02T14:32:54:  Lambda ....................: 1e-07
- 2011-02-02T14:32:54:  Maximum log likelihood ....: -33728.3
- 2011-02-02T14:32:54:  Npred .....................: 4048
- 2011-02-02T14:32:54: === GModels ===
- 2011-02-02T14:32:54:  Number of models ..........: 2
- 2011-02-02T14:32:54:  Number of parameters ......: 11
- 2011-02-02T14:32:54: === GModelPointSource ===
- 2011-02-02T14:32:54:  Name ......................: MAGIC Crab (Albert et al. 2008, ApJ, 674, 1037)
- 2011-02-02T14:32:54:  Instruments ...............: all
- 2011-02-02T14:32:54:  Number of parameters ......: 6
- 2011-02-02T14:32:54:  Number of spatial par's ...: 2
- 2011-02-02T14:32:54:   RA .......................: 83.6331 [-360,360] deg (fixed,scale=1)
- 2011-02-02T14:32:54:   DEC ......................: 22.0145 [-90,90] deg (fixed,scale=1)
- 2011-02-02T14:32:54:  Number of spectral par's ..: 3
- 2011-02-02T14:32:54:   Prefactor ................: 5.83432e-16 +/- 2.44527e-17 [1e-23,1e-13] ph/cm2/s/MeV (free,scale=1e-16)
- 2011-02-02T14:32:54:   Index ....................: -2.50725 +/- 0.0328297 [-0,-5]  (free,scale=-1)
- 2011-02-02T14:32:54:   PivotEnergy ..............: 300000 [10000,1e+09] MeV (fixed,scale=1e+06)
- 2011-02-02T14:32:54:  Number of temporal par's ..: 1
- 2011-02-02T14:32:54:   Constant .................: 1 (relative value) (fixed,scale=1)
- 2011-02-02T14:32:54: === GCTAModelRadialAcceptance ===
- 2011-02-02T14:32:54:  Name ......................: Background
- 2011-02-02T14:32:54:  Instruments ...............: CTA
- 2011-02-02T14:32:54:  Model type ................: "Gaussian" * "PowerLaw" * "Constant"
- 2011-02-02T14:32:54:  Number of parameters ......: 5
- 2011-02-02T14:32:54:  Number of radial par's ....: 1
- 2011-02-02T14:32:54:   Sigma ....................: 3.03472 +/- 0.0398509 [0.01,10] deg2 (free,scale=1)
- 2011-02-02T14:32:54:  Number of spectral par's ..: 3
- 2011-02-02T14:32:54:   Prefactor ................: 6.18897e-05 +/- 1.74306e-06 [0,0.001] ph/cm2/s/MeV (free,scale=1e-06)
- 2011-02-02T14:32:54:   Index ....................: -1.86369 +/- 0.0156024 [-0,-5]  (free,scale=-1)
- 2011-02-02T14:32:54:   PivotEnergy ..............: 1e+06 [10000,1e+09] MeV (fixed,scale=1e+06)
- 2011-02-02T14:32:54:  Number of temporal par's ..: 1
- 2011-02-02T14:32:54:   Constant .................: 1 (relative value) (fixed,scale=1)
- 2011-02-02T14:32:54:
- 2011-02-02T14:32:54: Application "ctlike" terminated after consuming 2 seconds of CPU time.
-

-
-
-

Some -final remarks

- +final remarks (updated for ctatools-00-02-03)

First you should notice that ctatools are in the prototyping phase. If GammaLib and ctatools are installed on your system you should be able to run the above example without any problems, and you can do even much more.

-
-

You may specify longer integration times for the simulation and for the analysis, you can have several point sources in the @@ -1176,66 +806,52 @@ generator, hence you cannot simulate events for spectral laws different from power laws for the moment. You may try, however, fitting the sources with other spectral laws, yet I have not tried this, and I cannot guarantee that it works.

-
-

There is also only one radial acceptance model defined so far, and you should use the model definition that is given in the example.

-
- -

Also, -don't fiddle around with -other projections and coordinate systems in -ctbin. -The cartesian projection is the only one that so far is -implemented, and galactic coordinates have not been tested so far.

- +

So far, there are four projection types supported: AZP, CAR, STG, and TAN. You can use them in Galactic (GAL) or celestial (CEL) coordinates.


-

The instrument response function that has been implemented so far in GammaLib (yes, it is in GammaLib, not in ctatools) is very simple. It -just reads Konrad's effective area files to get an effective area that is so far -independent of offset angle. ctobssim +just reads Konrad's effective area files to get the onaxis effective +area. It is assumed that the effective area varies with offset angle, +and a Gaussian as function of offset angle squared has been implemented +for the functional form of this variation. By default, the sigma of this Gaussian is fixed to 3 deg2. +This value can not be modified using the ctatools, but it can be +altered using the Python interface. In any case, this treatment of the +offset angle dependence is only preliminary and will be changed as soon as a format has been defined for the CTA response functions.

ctobssim and ctlike query for the name of the instrument response function file, and you may specify different -response files if you like. To see what is available, type (adjust the +response files if you want to study the impact of array configuration on the results. To see what is available, type (adjust the path corresponding to your installation directory):

-

> ls /usr/local/gamma/share/caldb/cta
- kb_A_50h_v3.dat         kb_D_50h_v3.dat         kb_G_50h_v3.dat         kb_J_50h_v3.dat         kb_NB_50h_v3.dat
- kb_B_50h_v3.dat         kb_E_50h_v3.dat         kb_H_50h_v3.dat         kb_K_50h_v3.dat
- kb_C_50h_v3.dat         kb_F_50h_v3.dat         kb_I_50h_v3.dat         kb_NA_50h_v3.dat
-

-

The point spread function (PSF) definition is also read from these files. So far, the PSF is a simple Gaussian. The energy dependent Gaussian width is defined by the r68 parameter in Konrad's response files.

-
-

Lifetime is assumed to be 100%. I'm not sure whether lifetime is folded in the @@ -1243,37 +859,33 @@ effective areas of Konrad's response files, if not, a corresponding correction should be applied to all source fluxes obtained with the ctatools.

-
-

Finally, if you want to have the log file also dumped to the screen as the executable runs, add debug=yes on the command line, e.g.

-

> ctlike debug=yes

-

And now: enjoy playing with ctatools.

-
-
-

Getting Help

-

Any questions, bug reports, or suggested enhancements related to ctatools and GammaLib should be submitted to knodlseder@cesr.fr .

- - - +
+
+

Last updated by: Jürgen +Knödlseder 9 July +2011 +

+ \ No newline at end of file