Description

Sequence function: y = sequence_of_functions(f1(y), f2(y), f3(y)) All other function types can be inserted into this.

#include <ChFunctionSequence.h>

Inheritance diagram for chrono::ChFunctionSequence:
Collaboration diagram for chrono::ChFunctionSequence:

Public Member Functions

 ChFunctionSequence (const ChFunctionSequence &other)
 
virtual ChFunctionSequenceClone () const override
 "Virtual" copy constructor (covariant return type).
 
virtual Type GetType () const override
 Return the unique function type identifier.
 
virtual double GetVal (double x) const override
 Return the function output for input x. More...
 
virtual double GetDer (double x) const override
 Return the first derivative of the function. More...
 
virtual double GetDer2 (double x) const override
 Return the second derivative of the function. More...
 
void SetStartArg (double start)
 The sequence of functions starts at this x value.
 
double GetStartArg () const
 The sequence of functions starts at this x value.
 
std::list< ChFseqNode > & GetFunctions ()
 Access the list of the sub-functions.
 
void Setup ()
 Scans all the seq.of functions and setup the timings and continuity offsets, to satisfy all constraints. More...
 
bool InsertFunct (std::shared_ptr< ChFunction > myfx, double duration, double weight=1, bool c0=false, bool c1=false, bool c2=false, int position=-1)
 Insert function after the fx with defined "position" index in list. More...
 
bool RemoveFunct (int index)
 Remove and deletes function with defined "position", and returns true. More...
 
std::shared_ptr< ChFunctionGetFunction (int index)
 Returns the ChFunction with given "index". More...
 
ChFseqNodeGetNode (int index)
 As above, but returns the function node (containing function pointer, function duration, continuity flags with previous node, etc.)
 
double GetWidth (int index)
 As above, but returning duration. More...
 
virtual double GetWeight (double x) const override
 Return the weight of the function. More...
 
virtual void ArchiveOut (ChArchiveOut &archive_out) override
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIn (ChArchiveIn &archive_in) override
 Method to allow de-serialization of transient data from archives.
 
- Public Member Functions inherited from chrono::ChFunction
 ChFunction (const ChFunction &other)
 
virtual double GetDer3 (double x) const
 Return the third derivative of the function. More...
 
virtual double GetDerN (double x, int der_order) const
 Return the Nth derivative of the function (up to 3rd derivative). More...
 
virtual void Update (double x)
 Update the function at the provided value of its argument.
 
virtual double GetMax (double xmin, double xmax, double sampling_step, int der_order) const
 Estimate the maximum of the function (or its der_order derivative) in the range [xmin, xmax]. More...
 
virtual double GetMin (double xmin, double xmax, double sampling_step, int der_order) const
 Estimate the minimum of the function (or its der_order derivative) in the range [xmin, xmax]. More...
 
virtual double GetMean (double xmin, double xmax, double sampling_step, int der_order) const
 Estimate the mean of the function (or its der_order derivative) in the range [xmin, xmax]. More...
 
virtual double GetSquaredMean (double xmin, double xmax, double sampling_step, int der_order) const
 Estimate the squared mean of the function (or its der_order derivative) in the range [xmin, xmax]. More...
 
virtual double GetIntegral (double xmin, double xmax, double sampling_step, int der_order) const
 Estimate the integral of the function (or its der_order derivative) over the range [xmin, xmax]. More...
 
virtual double GetPositiveAccelerationCoeff () const
 Compute the positive acceleration coefficient. More...
 
virtual double GetNegativeAccelerationCoeff () const
 Compute the negative acceleration coefficient. More...
 
virtual double GetVelocityCoefficient () const
 Compute the velocity coefficient. More...
 
virtual void OutputToASCIIFile (std::ostream &file, double xmin, double xmax, int samples, char delimiter)
 Store X-Y pairs to an ASCII File. More...
 
virtual ChMatrixDynamic SampleUpToDerN (double xmin, double xmax, double step, int derN=0)
 Sample function on given interval [xmin, xmax], up to derN derivative (0 being the function ouput itself). More...
 
double operator() (double arg) const
 Alias operator of the GetVal function.
 

Protected Attributes

std::list< ChFseqNodem_functions
 the list of sub functions
 
double m_start
 start time for sequence
 

Additional Inherited Members

- Public Types inherited from chrono::ChFunction
enum  Type {
  BSPLINE, CONSTANT, CONSTACC, CONSTJERK,
  CUSTOM, CYCLOIDAL, DERIVATIVE, FILLET3,
  INTEGRAL, INTERP, LAMBDA, MIRROR,
  OPERATOR, POLY, POLY23, POLY345,
  RAMP, REPEAT, SEQUENCE, SINE,
  SINE_STEP
}
 Enumeration of function types.
 

Member Function Documentation

◆ GetDer()

double chrono::ChFunctionSequence::GetDer ( double  x) const
overridevirtual

Return the first derivative of the function.

Default implementation computes a numerical differentiation. Inherited classes may override this method with a more efficient implementation (e.g. analytical solution).

Reimplemented from chrono::ChFunction.

◆ GetDer2()

double chrono::ChFunctionSequence::GetDer2 ( double  x) const
overridevirtual

Return the second derivative of the function.

Default implementation computes a numerical differentiation. Inherited classes may override this method with a more efficient implementation (e.g. analytical solution).

Reimplemented from chrono::ChFunction.

◆ GetFunction()

std::shared_ptr< ChFunction > chrono::ChFunctionSequence::GetFunction ( int  index)

Returns the ChFunction with given "index".

  • If index = 0, returns always head (beginning),
  • If index = -1 returns tail (end).
  • If index > max number of current nodes, returns tail fx anyway.

◆ GetVal()

double chrono::ChFunctionSequence::GetVal ( double  x) const
overridevirtual

Return the function output for input x.

Must be overridden by specialized classes.

Implements chrono::ChFunction.

◆ GetWeight()

double chrono::ChFunctionSequence::GetWeight ( double  x) const
overridevirtual

Return the weight of the function.

(useful for applications where you need to mix different weighted ChFunctions)

Reimplemented from chrono::ChFunction.

◆ GetWidth()

double chrono::ChFunctionSequence::GetWidth ( int  index)

As above, but returning duration.

(return value is reference, so it can be also changed later, but remember Setup() for the ChFunctionSequence after you modified this return value by reference TO DO). If no function, returns 0.

◆ InsertFunct()

bool chrono::ChFunctionSequence::InsertFunct ( std::shared_ptr< ChFunction myfx,
double  duration,
double  weight = 1,
bool  c0 = false,
bool  c1 = false,
bool  c2 = false,
int  position = -1 
)

Insert function after the fx with defined "position" index in list.

  • If index is higher than available objects, it simply goes to the end.
  • If index = 0 insert at the beginning,
  • If index = -1 insert at the end. Inserted functions will be deleted automatically when this object will be deleted. The fx segment has its own 'weight': use 1.0 for default, or different weights if you want that GetWeight() will give different results depending on the "x" parameter. Set c0=true if you want to force C0 continuity with previous function (an offset will be implicitly added to the function, as y=f(x)+Offset). Same for C1 and C2 continuity, using c1 and c2 flags.
Parameters
myfxthe function to insert
durationduration of the time segment for this function
weightoptional weight scalar
c0impose continuity to previous f() by offsetting/slanting
c1impose continuity to previous f() by offsetting/slanting
c2impose continuity to previous f() by offsetting/slanting
positionposition index, 0,1,2,3.. (if -1 insert at the end)

◆ RemoveFunct()

bool chrono::ChFunctionSequence::RemoveFunct ( int  index)

Remove and deletes function with defined "position", and returns true.

  • If index = 0, removes always head (beginning),
  • If index = -1 removes tail (end).
  • If index > max number of current nodes, removes tail anyway, but returns false.

◆ Setup()

void chrono::ChFunctionSequence::Setup ( )

Scans all the seq.of functions and setup the timings and continuity offsets, to satisfy all constraints.

This must be called whenever a new function is inserted, or its timing and continuity constraints are changed.


The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono/functions/ChFunctionSequence.h
  • /builds/uwsbel/chrono/src/chrono/functions/ChFunctionSequence.cpp