JSBSim Flight Dynamics Model  1.0 (02 March 2017)
An Open Source Flight Dynamics and Control Software Library in C++
Public Member Functions | List of all members
FGTable Class Reference

Lookup table class. More...

#include <FGTable.h>

+ Inheritance diagram for FGTable:
+ Collaboration diagram for FGTable:

Public Member Functions

 FGTable (const FGTable &table)
 This is the very important copy constructor. More...
 
 FGTable (FGPropertyManager *propMan, Element *el)
 The constructor for a table.
 
 FGTable (int)
 
 FGTable (int, int)
 
 ~FGTable ()
 Destructor.
 
double GetElement (int r, int c) const
 
std::string GetName (void) const
 
unsigned int GetNumRows () const
 
double GetValue (void) const
 
double GetValue (double key) const
 
double GetValue (double rowKey, double colKey) const
 
double GetValue (double rowKey, double colKey, double TableKey) const
 
double operator() (unsigned int r, unsigned int c) const
 
void operator<< (std::istream &)
 Read the table in. More...
 
FGTable & operator<< (const double n)
 
FGTable & operator<< (const int n)
 
void Print (void)
 
void SetColumnIndexProperty (FGPropertyNode *node)
 
void SetRowIndexProperty (FGPropertyNode *node)
 
- Public Member Functions inherited from FGParameter
double getDoubleValue (void) const
 
- Public Member Functions inherited from FGJSBBase
 FGJSBBase ()
 Constructor for FGJSBBase.
 
virtual ~FGJSBBase ()
 Destructor for FGJSBBase.
 
void disableHighLighting (void)
 Disables highlighting in the console output.
 
std::string GetVersion (void)
 Returns the version number of JSBSim. More...
 
void PutMessage (const Message &msg)
 Places a Message structure on the Message queue. More...
 
void PutMessage (const std::string &text)
 Creates a message with the given text and places it on the queue. More...
 
void PutMessage (const std::string &text, bool bVal)
 Creates a message with the given text and boolean value and places it on the queue. More...
 
void PutMessage (const std::string &text, int iVal)
 Creates a message with the given text and integer value and places it on the queue. More...
 
void PutMessage (const std::string &text, double dVal)
 Creates a message with the given text and double value and places it on the queue. More...
 
int SomeMessages (void)
 Reads the message on the queue (but does not delete it). More...
 
void ProcessMessage (void)
 Reads the message on the queue and removes it from the queue. More...
 
Message * ProcessNextMessage (void)
 Reads the next message on the queue and removes it from the queue. More...
 

Additional Inherited Members

- Public Types inherited from FGJSBBase
enum  { eL = 1, eM, eN }
 Moments L, M, N.
 
enum  { eP = 1, eQ, eR }
 Rates P, Q, R.
 
enum  { eU = 1, eV, eW }
 Velocities U, V, W.
 
enum  { eX = 1, eY, eZ }
 Positions X, Y, Z.
 
enum  { ePhi = 1, eTht, ePsi }
 Euler angles Phi, Theta, Psi.
 
enum  { eDrag = 1, eSide, eLift }
 Stability axis forces, Drag, Side force, Lift.
 
enum  { eRoll = 1, ePitch, eYaw }
 Local frame orientation Roll, Pitch, Yaw.
 
enum  { eNorth = 1, eEast, eDown }
 Local frame position North, East, Down.
 
enum  { eLat = 1, eLong, eRad }
 Locations Radius, Latitude, Longitude.
 
enum  {
  inNone = 0, inDegrees, inRadians, inMeters,
  inFeet
}
 Conversion specifiers.
 
- Static Public Member Functions inherited from FGJSBBase
static double CelsiusToFahrenheit (double celsius)
 Converts from degrees Celsius to degrees Fahrenheit. More...
 
static double CelsiusToKelvin (double celsius)
 Converts from degrees Celsius to degrees Kelvin. More...
 
static double CelsiusToRankine (double celsius)
 Converts from degrees Celsius to degrees Rankine. More...
 
static double Constrain (double min, double value, double max)
 Constrain a value between a minimum and a maximum value.
 
static bool EqualToRoundoff (double a, double b)
 Finite precision comparison. More...
 
static bool EqualToRoundoff (float a, float b)
 Finite precision comparison. More...
 
static bool EqualToRoundoff (float a, double b)
 Finite precision comparison. More...
 
static bool EqualToRoundoff (double a, float b)
 Finite precision comparison. More...
 
static double FahrenheitToCelsius (double fahrenheit)
 Converts from degrees Fahrenheit to degrees Celsius. More...
 
static double FeetToMeters (double measure)
 Converts from feet to meters. More...
 
static double GaussianRandomNumber (void)
 
static double KelvinToCelsius (double kelvin)
 Converts from degrees Kelvin to degrees Celsius. More...
 
static double KelvinToFahrenheit (double kelvin)
 Converts from degrees Kelvin to degrees Fahrenheit. More...
 
static double KelvinToRankine (double kelvin)
 Converts from degrees Kelvin to degrees Rankine. More...
 
static double MachFromVcalibrated (double vcas, double p, double psl, double rhosl)
 Calculate the Mach number from the calibrated airspeed. More...
 
static double PitotTotalPressure (double mach, double p)
 Compute the total pressure in front of the Pitot tube. More...
 
static double RankineToCelsius (double rankine)
 Converts from degrees Rankine to degrees Celsius. More...
 
static double RankineToKelvin (double rankine)
 Converts from degrees Rankine to degrees Kelvin. More...
 
static double sign (double num)
 
static double VcalibratedFromMach (double mach, double p, double psl, double rhosl)
 Calculate the calibrated airspeed from the Mach number. More...
 
- Static Public Attributes inherited from FGJSBBase
static short debug_lvl = 1
 
static char highint [5] = {27, '[', '1', 'm', '\0' }
 highlights text
 
static char halfint [5] = {27, '[', '2', 'm', '\0' }
 low intensity text
 
static char normint [6] = {27, '[', '2', '2', 'm', '\0' }
 normal intensity text
 
static char reset [5] = {27, '[', '0', 'm', '\0' }
 resets text properties
 
static char underon [5] = {27, '[', '4', 'm', '\0' }
 underlines text
 
static char underoff [6] = {27, '[', '2', '4', 'm', '\0' }
 underline off
 
static char fgblue [6] = {27, '[', '3', '4', 'm', '\0' }
 blue text
 
static char fgcyan [6] = {27, '[', '3', '6', 'm', '\0' }
 cyan text
 
static char fgred [6] = {27, '[', '3', '1', 'm', '\0' }
 red text
 
static char fggreen [6] = {27, '[', '3', '2', 'm', '\0' }
 green text
 
static char fgdef [6] = {27, '[', '3', '9', 'm', '\0' }
 default text
 
- Protected Member Functions inherited from FGJSBBase
void Debug (int)
 
- Static Protected Member Functions inherited from FGJSBBase
static std::string CreateIndexedPropertyName (const std::string &Property, int index)
 
- Static Protected Attributes inherited from FGJSBBase
static const double degtorad = 0.017453292519943295769236907684886
 
static const double fpstokts = 1.0/ktstofps
 
static const double fttom = 0.3048
 
static int gaussian_random_number_phase = 0
 
static const double hptoftlbssec = 550.0
 
static const double in3tom3 = 1.638706E-5
 
static const double inchtoft = 0.08333333
 
static const double inhgtopa = 3386.38
 
static const std::string JSBSim_version = "1.0 " __DATE__ " " __TIME__
 
static const double kgtolb = 2.20462
 
static const double kgtoslug = 0.06852168
 
static const double ktstofps = 1.68781
 
static const double lbtoslug = 1.0/slugtolb
 
static Message localMsg
 
static const double m3toft3 = 1.0/(fttom*fttom*fttom)
 
static double Mair = 28.9645
 
static unsigned int messageId = 0
 
static std::queue< Message > Messages
 
static const std::string needed_cfg_version = "2.0"
 
static const double psftoinhg = 0.014138
 
static const double psftopa = 47.88
 
static const double radtodeg = 57.295779513082320876798154814105
 
static double Reng = 1716.56
 
static double Rstar = 1545.348
 
static const double SHRatio = 1.40
 
static const double slugtolb = 32.174049
 

Detailed Description

Lookup table class.

Models a one, two, or three dimensional lookup table for use in aerodynamics and function definitions.

For a single "vector" lookup table, the format is as follows:

<table name="property_name">
<independentVar lookup="row"> property_name </independentVar>
<tableData>
key_1 value_1
key_2 value_2
... ...
key_n value_n
</tableData>
</table>

The lookup="row" attribute in the independentVar element is option in this case; it is assumed that the independentVar is a row variable.

A "real life" example is as shown here:

<table>
<independentVar lookup="row"> aero/alpha-rad </independentVar>
<tableData>
-1.57 1.500
-0.26 0.033
0.00 0.025
0.26 0.033
1.57 1.500
</tableData>
</table>

The first column in the data table represents the lookup index (or "key"). In this case, the lookup index is aero/alpha-rad (angle of attack in radians). If alpha is 0.26 radians, the value returned from the lookup table would be 0.033.

The definition for a 2D table, is as follows:

<table name="property_name">
<independentVar lookup="row"> property_name </independentVar>
<independentVar lookup="column"> property_name </independentVar>
<tableData>
{col_1_key col_2_key ... col_n_key }
{row_1_key} {col_1_data col_2_data ... col_n_data}
{row_2_key} {... ... ... ... }
{ ... } {... ... ... ... }
{row_n_key} {... ... ... ... }
</tableData>
</table>

The data is in a gridded format.

A "real life" example is as shown below. Alpha in radians is the row lookup (alpha breakpoints are arranged in the first column) and flap position in degrees is

<table>
<independentVar lookup="row">aero/alpha-rad</independentVar>
<independentVar lookup="column">fcs/flap-pos-deg</independentVar>
<tableData>
0.0 10.0 20.0 30.0
-0.0523599 8.96747e-05 0.00231942 0.0059252 0.00835082
-0.0349066 0.000313268 0.00567451 0.0108461 0.0140545
-0.0174533 0.00201318 0.0105059 0.0172432 0.0212346
0.0 0.0051894 0.0168137 0.0251167 0.0298909
0.0174533 0.00993967 0.0247521 0.0346492 0.0402205
0.0349066 0.0162201 0.0342207 0.0457119 0.0520802
0.0523599 0.0240308 0.0452195 0.0583047 0.0654701
0.0698132 0.0333717 0.0577485 0.0724278 0.0803902
0.0872664 0.0442427 0.0718077 0.088081 0.0968405
</tableData>
</table>

The definition for a 3D table in a coefficient would be (for example):

<table name="property_name">
<independentVar lookup="row"> property_name </independentVar>
<independentVar lookup="column"> property_name </independentVar>
<tableData breakpoint="table_1_key">
{col_1_key col_2_key ... col_n_key }
{row_1_key} {col_1_data col_2_data ... col_n_data}
{row_2_key} {... ... ... ... }
{ ... } {... ... ... ... }
{row_n_key} {... ... ... ... }
</tableData>
<tableData breakpoint="table_2_key">
{col_1_key col_2_key ... col_n_key }
{row_1_key} {col_1_data col_2_data ... col_n_data}
{row_2_key} {... ... ... ... }
{ ... } {... ... ... ... }
{row_n_key} {... ... ... ... }
</tableData>
...
<tableData breakpoint="table_n_key">
{col_1_key col_2_key ... col_n_key }
{row_1_key} {col_1_data col_2_data ... col_n_data}
{row_2_key} {... ... ... ... }
{ ... } {... ... ... ... }
{row_n_key} {... ... ... ... }
</tableData>
</table>

[Note the "breakpoint" attribute in the tableData element, above.]

Here's an example:

<table>
<independentVar lookup="row">fcs/row-value</independentVar>
<independentVar lookup="column">fcs/column-value</independentVar>
<independentVar lookup="table">fcs/table-value</independentVar>
<tableData breakPoint="-1.0">
-1.0 1.0
0.0 1.0000 2.0000
1.0 3.0000 4.0000
</tableData>
<tableData breakPoint="0.0000">
0.0 10.0
2.0 1.0000 2.0000
3.0 3.0000 4.0000
</tableData>
<tableData breakPoint="1.0">
0.0 10.0 20.0
2.0 1.0000 2.0000 3.0000
3.0 4.0000 5.0000 6.0000
10.0 7.0000 8.0000 9.0000
</tableData>
</table>

In addition to using a Table for something like a coefficient, where all the row and column elements are read in from a file, a Table could be created and populated completely within program code:

// First column is thi, second is neta (combustion efficiency)
Lookup_Combustion_Efficiency = new FGTable(12);
*Lookup_Combustion_Efficiency << 0.00 << 0.980;
*Lookup_Combustion_Efficiency << 0.90 << 0.980;
*Lookup_Combustion_Efficiency << 1.00 << 0.970;
*Lookup_Combustion_Efficiency << 1.05 << 0.950;
*Lookup_Combustion_Efficiency << 1.10 << 0.900;
*Lookup_Combustion_Efficiency << 1.15 << 0.850;
*Lookup_Combustion_Efficiency << 1.20 << 0.790;
*Lookup_Combustion_Efficiency << 1.30 << 0.700;
*Lookup_Combustion_Efficiency << 1.40 << 0.630;
*Lookup_Combustion_Efficiency << 1.50 << 0.570;
*Lookup_Combustion_Efficiency << 1.60 << 0.525;
*Lookup_Combustion_Efficiency << 2.00 << 0.345;

The first column in the table, above, is thi (the lookup index, or key). The second column is the output data - in this case, "neta" (the Greek letter referring to combustion efficiency). Later on, the table is used like this:

combustion_efficiency = Lookup_Combustion_Efficiency->GetValue(equivalence_ratio);
Author
Jon S. Berndt
Version
Id
FGTable.h,v 1.15 2013/01/26 17:06:49 bcoconni Exp

Definition at line 243 of file FGTable.h.

Constructor & Destructor Documentation

◆ FGTable()

FGTable ( const FGTable &  table)

This is the very important copy constructor.

Parameters
tablea const reference to a table.

Definition at line 85 of file FGTable.cpp.

85  : PropertyManager(t.PropertyManager)
86 {
87  Type = t.Type;
88  colCounter = t.colCounter;
89  rowCounter = t.rowCounter;
90  tableCounter = t.tableCounter;
91  nRows = t.nRows;
92  nCols = t.nCols;
93  nTables = t.nTables;
94  dimension = t.dimension;
95  internal = t.internal;
96  Name = t.Name;
97  lookupProperty[0] = t.lookupProperty[0];
98  lookupProperty[1] = t.lookupProperty[1];
99  lookupProperty[2] = t.lookupProperty[2];
100 
101  Tables = t.Tables;
102  Data = Allocate();
103  for (unsigned int r=0; r<=nRows; r++) {
104  for (unsigned int c=0; c<=nCols; c++) {
105  Data[r][c] = t.Data[r][c];
106  }
107  }
108  lastRowIndex = t.lastRowIndex;
109  lastColumnIndex = t.lastColumnIndex;
110  lastTableIndex = t.lastTableIndex;
111 }
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Member Function Documentation

◆ operator<<()

void operator<< ( std::istream &  in_stream)

Read the table in.

Data in the config file should be in matrix format with the row independents as the first column and the column independents in the first row. The implication of this layout is that there should be no value in the upper left corner of the matrix e.g: 

     0  10  20 30 ...
-5   1  2   3  4  ...
 ...

For multiple-table (i.e. 3D) data sets there is an additional number key in the table definition. For example:

 0.0
     0  10  20 30 ...
-5   1  2   3  4  ...
 ...

Definition at line 544 of file FGTable.cpp.

545 {
546  int startRow=0;
547  int startCol=0;
548 
549 // In 1D table, no pseudo-row of column-headers (i.e. keys):
550  if (Type == tt1D) startRow = 1;
551 
552  for (unsigned int r=startRow; r<=nRows; r++) {
553  for (unsigned int c=startCol; c<=nCols; c++) {
554  if (r != 0 || c != 0) {
555  in_stream >> Data[r][c];
556  }
557  }
558  }
559 }
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The documentation for this class was generated from the following files: