Reference documentation for deal.II version 8.1.0
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MultipleParameterLoop Class Reference

#include <parameter_handler.h>

Inheritance diagram for MultipleParameterLoop:
[legend]

Classes

class  Entry
 
class  UserClass
 

Public Member Functions

 MultipleParameterLoop ()
 
virtual ~MultipleParameterLoop ()
 
virtual bool read_input (std::istream &input, const std::string &filename="input file")
 
virtual bool read_input (const std::string &FileName, const bool optional=false, const bool write_stripped_file=false)
 
virtual bool read_input_from_string (const char *s)
 
void loop (UserClass &uc)
 
std::size_t memory_consumption () const
 
- Public Member Functions inherited from ParameterHandler
 ParameterHandler ()
 
virtual ~ParameterHandler ()
 
virtual bool read_input_from_xml (std::istream &input)
 
void clear ()
 
void declare_entry (const std::string &entry, const std::string &default_value, const Patterns::PatternBase &pattern=Patterns::Anything(), const std::string &documentation=std::string())
 
void enter_subsection (const std::string &subsection)
 
bool leave_subsection ()
 
std::string get (const std::string &entry_string) const
 
long int get_integer (const std::string &entry_string) const
 
double get_double (const std::string &entry_name) const
 
bool get_bool (const std::string &entry_name) const
 
void set (const std::string &entry_name, const std::string &new_value)
 
void set (const std::string &entry_name, const char *new_value)
 
void set (const std::string &entry_name, const long int &new_value)
 
void set (const std::string &entry_name, const double &new_value)
 
void set (const std::string &entry_name, const bool &new_value)
 
std::ostream & print_parameters (std::ostream &out, const OutputStyle style)
 
void print_parameters_section (std::ostream &out, const OutputStyle style, const unsigned int indent_level)
 
void log_parameters (LogStream &out)
 
void log_parameters_section (LogStream &out)
 
std::size_t memory_consumption () const
 
template<class Archive >
void save (Archive &ar, const unsigned int version) const
 
template<class Archive >
void load (Archive &ar, const unsigned int version)
 
bool operator== (const ParameterHandler &prm2) const
 
 DeclException1 (ExcEntryAlreadyExists, std::string,<< "The following entry already exists: "<< arg1)
 
 DeclException2 (ExcValueDoesNotMatchPattern, std::string, std::string,<< "The string <"<< arg1<< "> does not match the given pattern <"<< arg2<< ">")
 
 DeclException0 (ExcAlreadyAtTopLevel)
 
 DeclException1 (ExcEntryUndeclared, std::string,<< "You can't ask for entry <"<< arg1<< "> you have not yet declared")
 
 DeclException1 (ExcConversionError, std::string,<< "Error when trying to convert the following string: "<< arg1)
 
- Public Member Functions inherited from Subscriptor
 Subscriptor ()
 
 Subscriptor (const Subscriptor &)
 
virtual ~Subscriptor ()
 
Subscriptoroperator= (const Subscriptor &)
 
void subscribe (const char *identifier=0) const
 
void unsubscribe (const char *identifier=0) const
 
unsigned int n_subscriptions () const
 
void list_subscribers () const
 
 DeclException3 (ExcInUse, int, char *, std::string &,<< "Object of class "<< arg2<< " is still used by "<< arg1<< " other objects.\n"<< "(Additional information: "<< arg3<< ")\n"<< "Note the entry in the Frequently Asked Questions of "<< "deal.II (linked to from http://www.dealii.org/) for "<< "more information on what this error means.")
 
 DeclException2 (ExcNoSubscriber, char *, char *,<< "No subscriber with identifier \""<< arg2<< "\" did subscribe to this object of class "<< arg1)
 
template<class Archive >
void serialize (Archive &ar, const unsigned int version)
 

Private Member Functions

void init_branches ()
 
void init_branches_current_section ()
 
void fill_entry_values (const unsigned int run_no)
 

Private Attributes

std::vector< Entrymultiple_choices
 
unsigned int n_branches
 

Additional Inherited Members

- Public Types inherited from ParameterHandler
enum  OutputStyle {
  Text = 1, LaTeX = 2, Description = 3, XML = 4,
  JSON = 5, ShortText = 193
}
 

Detailed Description

The class MultipleParameterLoop offers an easy possibility to test several parameter sets during one run of the program. For this it uses the ParameterHandler class to read in data in a standardized form, searches for variant entry values and performs a loop over all combinations of parameters.

Variant entry values are given like this:

*     set Time step size = { 0.1 | 0.2 | 0.3 }
*   

The loop will then perform three runs of the program, one for each value of Time step size, while all other parameters are as specified or with their default value. If there are several variant entry values in the input, a loop is performed for each combination of variant values:

*     set Time step size = { 0.1 | 0.2 }
*     set Solver         = { CG  | GMRES }
*   

will result in four runs of the programs, with time step 0.1 and 0.2 for each of the two solvers.

In addition to variant entries, this class also supports array entries that look like this:

*     set Output file = ofile.{{ 1 | 2 | 3 | 4 }}
*   

This indicates that if there are variant entries producing a total of four different runs, then we will write their results to the files ofile.1, ofile.2, ofile.3 and ofile.4, respectively. Array entries do not generate multiple runs of the main loop themselves, but if there are variant entries, then in the nth run of the main loop, also the nth value of an array is returned.

Since the different variants are constructed in the order of declaration, not in the order in which the variant entries appear in the input file, it may be difficult to guess the mapping between the different variants and the appropriate entry in an array. You will have to check the order of declaration, or use only one variant entry.

It is guaranteed that only selections which match the regular expression (pattern) given upon declaration of an entry are given back to the program. If a variant value does not match the regular expression, the default value is stored and an error is issued. Before the first run of the loop, all possible values are checked for their conformance, so that the error is issued at the very beginning of the program.

<h3>Usage</h3>

The usage of this class is similar to the ParameterHandler class.
First the entries and subsections have to be declared, then a loop is
performed in which the different parameter sets are set, a new
instance of a user class is created which is then called. Taking the
classes of the example for the ParameterHandler class, the extended
program would look like this:
class HelperClass : public MultipleParameterLoop::UserClass {
public:
HelperClass ();
virtual void create_new (const unsigned int run_no);
virtual void declare_parameters (ParameterHandler &prm);
virtual void run (ParameterHandler &prm);
private:
Problem *p;
};
HelperClass::HelperClass () : p(0) {}
void HelperClass::create_new (const unsigned int run_no) {
if (p) delete p;
p = new Problem;
}
void HelperClass::declare_parameters (ParameterHandler &prm) {
// entries of the problem class
// note: must be static member!
Problem::declare_parameters (prm);
}
void HelperClass::run (ParameterHandler &prm) {
p->get_parameters (prm);
p->do_useful_work ();
}
void main () {
HelperClass h;
h.declare_parameters (prm);
prm.read_input ("prmtest.prm");
prm.loop (h);
}

As can be seen, first a new helper class has to be set up. This must contain a virtual constructor for a problem class. You can also derive your problem class from MultipleParameterLoop::UserClass and let create_new clear all member variables. If you have access to all inherited member variables in some way this is the recommended procedure. A third possibility is to use multiple inheritance and derive a helper class from both the MultipleParameterLoop::UserClass and the problem class. In any case, create_new has to provide a clean problem object which is the problem in the second and third possibility.

The derived class also has to provide for member functions which declare the entries and which run the program. Running the program includes getting the parameters out of the ParameterHandler object.

After defining an object of this helper class and an object of the MultipleParameterLoop class, the entries have to be declared in the same way as for the ParameterHandler class. Then the input has to be read. Finally the loop is called. This executes the following steps:

for (each combination)
{
UserObject.create_new (run_no);
// set parameters for this run
UserObject.run (*this);
}

UserObject is the parameter to the loop function. create_new is given the number of the run (starting from one) to enable naming output files differently for each run.

<h3>Syntax for variant and array entry values</h3>

Variant values are specified like <tt>prefix{ v1 | v2 | v3 | ... }postfix</tt>. Whitespace
to the right of the opening brace <tt>{</tt> is ignored as well as to the left of the
closing brace <tt>}</tt> while whitespace on the respectively other side is not ignored.
Whitespace around the mid symbols <tt>|</tt> is also ignored. The empty selection
<tt>prefix{ v1 | }postfix</tt> is also allowed and produces the strings <tt>prefixv1postfix</tt> and
<tt>prefixpostfix</tt>.

The syntax for array values is equal, apart from the double braces:
<tt>prefix{{ v1 | v2 | v3 }}postfix</tt>.


<h3>Worked example</h3>

Given the above extensions to the example program for the
ParameterHandler and the following input file
*     set Equation 1 = Poisson
*     set Equation 2 = Navier-Stokes
*     set Output file= results.{{ 1 | 2 | 3 | 4 | 5 | 6 }}
*
*     subsection Equation 1
*       set Matrix type = Sparse
*       subsection Linear solver
*         set Solver                       = CG
*         set Maximum number of iterations = { 10 | 20 | 30 }
*       end
*     end
*
*     subsection Equation 2
*       set Matrix type = Full
*       subsection Linear solver
*         set Solver                       = { BiCGStab | GMRES }
*         set Maximum number of iterations = 100
*       end
*     end
*   

this is the output:

*     LinEq: Method=CG, MaxIterations=10
*     LinEq: Method=BiCGStab, MaxIterations=100
*     Problem: outfile=results.1
*              eq1=Poisson, eq2=Navier-Stokes
*              Matrix1=Sparse, Matrix2=Full
*     LinEq: Method=CG, MaxIterations=20
*     LinEq: Method=BiCGStab, MaxIterations=100
*     Problem: outfile=results.2
*              eq1=Poisson, eq2=Navier-Stokes
*              Matrix1=Sparse, Matrix2=Full
*     LinEq: Method=CG, MaxIterations=30
*     LinEq: Method=BiCGStab, MaxIterations=100
*     Problem: outfile=results.3
*              eq1=Poisson, eq2=Navier-Stokes
*              Matrix1=Sparse, Matrix2=Full
*     LinEq: Method=CG, MaxIterations=10
*     LinEq: Method=GMRES, MaxIterations=100
*     Problem: outfile=results.4
*              eq1=Poisson, eq2=Navier-Stokes
*              Matrix1=Sparse, Matrix2=Full
*     LinEq: Method=CG, MaxIterations=20
*     LinEq: Method=GMRES, MaxIterations=100
*     Problem: outfile=results.5
*              eq1=Poisson, eq2=Navier-Stokes
*              Matrix1=Sparse, Matrix2=Full
*     LinEq: Method=CG, MaxIterations=30
*     LinEq: Method=GMRES, MaxIterations=100
*     Problem: outfile=results.6
*              eq1=Poisson, eq2=Navier-Stokes
*              Matrix1=Sparse, Matrix2=Full
*   

Since create_new gets the number of the run it would also be possible to output the number of the run.

@author Wolfgang Bangerth, October 1997, 2010

Definition at line 2202 of file parameter_handler.h.

Constructor & Destructor Documentation

MultipleParameterLoop::MultipleParameterLoop ( )

Constructor

virtual MultipleParameterLoop::~MultipleParameterLoop ( )
virtual

Destructor. Declare this only to have a virtual destructor, which is safer as we have virtual functions. It actually does nothing spectacular.

Member Function Documentation

virtual bool MultipleParameterLoop::read_input ( std::istream &  input,
const std::string &  filename = "input file" 
)
virtual

Read input from a stream until the stream returns the eof condition or error. The second argument can be used to denote the name of the file (if that's what the input stream represents) we are reading from; this is only used when creating output for error messages.

Return whether the read was successful.

Reimplemented from ParameterHandler.

virtual bool MultipleParameterLoop::read_input ( const std::string &  FileName,
const bool  optional = false,
const bool  write_stripped_file = false 
)
virtual

Read input from a file the name of which is given. The PathSearch class "PARAMETERS" is used to find the file.

Return whether the read was successful.

Unless optional is true, this function will automatically generate the requested file with default values if the file did not exist. This file will not contain additional comments if write_stripped_file is true.

Reimplemented from ParameterHandler.

virtual bool MultipleParameterLoop::read_input_from_string ( const char *  s)
virtual

Read input from a string in memory. The lines in memory have to be separated by \n characters.

Reimplemented from ParameterHandler.

void MultipleParameterLoop::loop ( UserClass uc)

run the central loop.

std::size_t MultipleParameterLoop::memory_consumption ( ) const

Determine an estimate for the memory consumption (in bytes) of this object.

void MultipleParameterLoop::init_branches ( )
private

Initialize the different branches, i.e. construct the combinations.

void MultipleParameterLoop::init_branches_current_section ( )
private

Traverse the section currently set by enter_subsection()/leave_subsection() and see which of the entries are variante/array entries. Then fill the multiple_choices variable using this information.

void MultipleParameterLoop::fill_entry_values ( const unsigned int  run_no)
private

Transfer the entry values for one run to the entry tree.

Member Data Documentation

std::vector<Entry> MultipleParameterLoop::multiple_choices
private

List of variant entry values.

Definition at line 2364 of file parameter_handler.h.

unsigned int MultipleParameterLoop::n_branches
private

Number of branches constructed from the different combinations of the variants. This obviously equals the number of runs to be performed.

Definition at line 2370 of file parameter_handler.h.


The documentation for this class was generated from the following file: