A tabulated spectrum. More...
Public Member Functions | |
| EGS_TabulatedSpectrum (int N, const EGS_Float *x, const EGS_Float *f, int Type=1, const char *fname=0) | |
| Construct a tabulated spectrum from the energies x and the probabilities f. More... | |
| EGS_Float | maxEnergy () const |
| EGS_Float | expectedAverage () const |
 Public Member Functions inherited from EGS_BaseSpectrum | |
| EGS_BaseSpectrum () | |
| Constructor. More... | |
| virtual | ~EGS_BaseSpectrum () |
| Destructor. Does nothing. | |
| const string & | getType () const |
| Get the spectrum type. More... | |
| EGS_Float | sampleEnergy (EGS_RandomGenerator *rndm) |
| Sample a particle energy. More... | |
| virtual bool | storeState (ostream &data_out) const |
| Store the state of the spectrum object into the stream data_out. More... | |
| virtual bool | setState (istream &data_in) |
| Set the state of the spectrum object from the data in the stream data_in. More... | |
| virtual bool | addState (istream &data_in) |
| Add to the state of this object the data from the stream data_in. More... | |
| virtual void | resetCounter () |
| Reset the state of this spectrum object. More... | |
| void | getSampledAverage (EGS_Float &e, EGS_Float &de) const |
| Get the average sampled energy and its statistical uncertainty. More... | |
| void | reportAverageEnergy () const |
| Report the average energy (expected and actually sampled). More... | |
Protected Member Functions | |
| void | setType (int Type, const char *fname) |
| EGS_Float | sample (EGS_RandomGenerator *rndm) |
Protected Attributes | |
| EGS_AliasTable * | table |
| The alias table object used to sample energies. | |
| Protected Attributes inherited from EGS_BaseSpectrum | |
| EGS_I64 | count |
| Number of times the sampleEnergy() method was called. | |
| double | sum_E |
| Sum of energies sampled so far. | |
| double | sum_E2 |
| Sum of energies squared sampled so far. | |
| string | type |
| A short string describing the spectrum that must be set by derived classes. | |
Additional Inherited Members | |
| Static Public Member Functions inherited from EGS_BaseSpectrum | |
| static EGS_BaseSpectrum * | createSpectrum (EGS_Input *inp) |
| Create and return a pointer to a spectrum object from the information pointed to by inp. More... | |
Detailed Description
A tabulated spectrum.
A tabulated spectrum can be used to simulate any type of energy distribution. Three different types of a tabulated spectrum are available:
- A line spectrum, i.e. the spectrum consists of a series of discrete energies
with probabilities 
. This type of spectrum is useful for instance for the simulation of some radioactive sources. - A histogram spectrum. In this case the spectrum consists of a series of energy bins
with probabilities , where the distribution within a bin is uniform. This is the type of spectrum implemented by ensrc.mortranand used in the standard set of EGSnrc mortran user codes. - An 'interpolated' spectrum. This is similar to a histogram spectrum, however, the probabilities are considered to be at the bin edges and a linear interpolation is used between the bin edges. As a result, an interpolated spectrum with
bins requires 
energies and probabilities, whereas a histogram spectrum with bins requires energies but probabilities.
Internally the tabulated spectrum object uses an alias table object to sample energies efficiently.
There are two ways for defining a tabulated spectrum by specifying the name of a file containing a spectrum definition, or inline. In the former case the keys needed to define a spectrum are
:start spectrum:
type = tabulated spectrum
spectrum file = the name of a spectrum file
:stop spectrum:
The syntax of the spectrum file is the same as for the standard set of EGSnrc user codes (see the example spectra distributed with the system in $HEN_HOUSE/spectra), except that now the mode of the file can also be 2 (line spectrum) or 3 (interpolated spectrum). A spectrum is defined inline as follows:
:start spectrum:
type = tabulated spectrum
energies = list of discrete energies or bin edges
probabilities = list of probabilities
spectrum type = 0 or 1 or 2 or 3
:stop spectrum:
where the meaning of the spectrum type is the same as the mode of a spectrum file.
Definition at line 383 of file egs_spectra.cpp.
Constructor & Destructor Documentation
| EGS_TabulatedSpectrum::EGS_TabulatedSpectrum | ( | int | N, |
| const EGS_Float * | x, | ||
| const EGS_Float * | f, | ||
| int | Type = 1, |
||
| const char * | fname = 0 |
||
| ) |
Construct a tabulated spectrum from the energies x and the probabilities f.
The interpretation of x and f depends on the spectrum type specified by Type. For Type=0,1 it is considered to be a histogram spectrum with N-1 bins defined by the N edge energies x. (the difference between a Type=0 and a Type=1 spectrum is that in the one case the probabilities f are considered to be counts per bin whereas in the latter case they are counts per MeV). For Type=2 the spectrum is considered to be a line spectrum with N discrete energies and probabilities given by x and f. For Type=3 the spectrum is considered to be an interpolated spectrum.
Definition at line 401 of file egs_spectra.cpp.
The documentation for this class was generated from the following file:
- /home/rwtownson/EGSnrc/HEN_HOUSE/egs++/egs_spectra.cpp
