src/FDM/JSBSim/input_output/FGXMLElement.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Author:       Jon Berndt
   4  Date started: 09/28/2004
   5  Purpose:      XML element class
   6  Called by:    FGXMLParse
   7
   8  ------------- Copyright (C) 2001  Jon S. Berndt (jon@jsbsim.org) -------------
   9
  10  This program is free software; you can redistribute it and/or modify it under
  11  the terms of the GNU Lesser General Public License as published by the Free Software
  12  Foundation; either version 2 of the License, or (at your option) any later
  13  version.
  14
  15  This program is distributed in the hope that it will be useful, but WITHOUT
  16  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
  18  details.
  19
  20  You should have received a copy of the GNU Lesser General Public License along with
  21  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  22  Place - Suite 330, Boston, MA  02111-1307, USA.
  23
  24  Further information about the GNU Lesser General Public License can also be found on
  25  the world wide web at http://www.gnu.org.
  26
  27 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  28 INCLUDES
  29 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  30
  31 #include "FGXMLElement.h"
  32
  33 #include <cmath>
  34 #include <cstdlib>
  35 #include <iostream>
  36
  37 using namespace std;
  38
  39 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  40 FORWARD DECLARATIONS
  41 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  42
  43 namespace JSBSim {
  44
  45 static const char *IdSrc = "$Id: FGXMLElement.cpp,v 1.32 2011/02/13 00:42:45 jberndt Exp $";
  46 static const char *IdHdr = ID_XMLELEMENT;
  47
  48 bool Element::converterIsInitialized = false;
  49 map <string, map <string, double> > Element::convert;
  50
  51 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  52 CLASS IMPLEMENTATION
  53 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  54
  55 Element::Element(const string& nm)
  56 {
  57   name   = nm;
  58   parent = 0L;
  59   element_index = 0;
  60
  61   if (!converterIsInitialized) {
  62     converterIsInitialized = true;
  63     // convert ["from"]["to"] = factor, so: from * factor = to
  64     // Length
  65     convert["M"]["FT"] = 3.2808399;
  66     convert["FT"]["M"] = 1.0/convert["M"]["FT"];
  67     convert["KM"]["FT"] = 3280.8399;
  68     convert["FT"]["KM"] = 1.0/convert["KM"]["FT"];
  69     convert["FT"]["IN"] = 12.0;
  70     convert["IN"]["FT"] = 1.0/convert["FT"]["IN"];
  71     convert["IN"]["M"] = convert["IN"]["FT"] * convert["FT"]["M"];
  72     convert["M"]["IN"] = convert["M"]["FT"] * convert["FT"]["IN"];
  73     // Area
  74     convert["M2"]["FT2"] = convert["M"]["FT"]*convert["M"]["FT"];
  75     convert["FT2"]["M2"] = 1.0/convert["M2"]["FT2"];
  76     convert["M2"]["IN2"] = convert["M"]["IN"]*convert["M"]["IN"];
  77     convert["IN2"]["M2"] = 1.0/convert["M2"]["IN2"];
  78     convert["FT2"]["IN2"] = 144.0;
  79     convert["IN2"]["FT2"] = 1.0/convert["FT2"]["IN2"];
  80     // Volume
  81     convert["IN3"]["CC"] = 16.387064;
  82     convert["CC"]["IN3"] = 1.0/convert["IN3"]["CC"];
  83     convert["FT3"]["IN3"] = 1728.0;
  84     convert["IN3"]["FT3"] = 1.0/convert["FT3"]["IN3"];
  85     convert["M3"]["FT3"] = 35.3146667;
  86     convert["FT3"]["M3"] = 1.0/convert["M3"]["FT3"];
  87     convert["LTR"]["IN3"] = 61.0237441;
  88     convert["IN3"]["LTR"] = 1.0/convert["LTR"]["IN3"];
  89     // Mass & Weight
  90     convert["LBS"]["KG"] = 0.45359237;
  91     convert["KG"]["LBS"] = 1.0/convert["LBS"]["KG"];
  92     convert["SLUG"]["KG"] = 14.59390;
  93     convert["KG"]["SLUG"] = 1.0/convert["SLUG"]["KG"];
  94     // Moments of Inertia
  95     convert["SLUG*FT2"]["KG*M2"] = 1.35594;
  96     convert["KG*M2"]["SLUG*FT2"] = 1.0/convert["SLUG*FT2"]["KG*M2"];
  97     // Angles
  98     convert["RAD"]["DEG"] = 180.0/M_PI;
  99     convert["DEG"]["RAD"] = 1.0/convert["RAD"]["DEG"];
 100     // Angular rates
 101     convert["RAD/SEC"]["DEG/SEC"] = convert["RAD"]["DEG"];
 102     convert["DEG/SEC"]["RAD/SEC"] = 1.0/convert["RAD/SEC"]["DEG/SEC"];
 103     // Spring force
 104     convert["LBS/FT"]["N/M"] = 14.5939;
 105     convert["N/M"]["LBS/FT"] = 1.0/convert["LBS/FT"]["N/M"];
 106     // Damping force
 107     convert["LBS/FT/SEC"]["N/M/SEC"] = 14.5939;
 108     convert["N/M/SEC"]["LBS/FT/SEC"] = 1.0/convert["LBS/FT/SEC"]["N/M/SEC"];
 109     // Damping force (Square Law)
 110     convert["LBS/FT2/SEC2"]["N/M2/SEC2"] = 47.880259;
 111     convert["N/M2/SEC2"]["LBS/FT2/SEC2"] = 1.0/convert["LBS/FT2/SEC2"]["N/M2/SEC2"];
 112     // Power
 113     convert["WATTS"]["HP"] = 0.001341022;
 114     convert["HP"]["WATTS"] = 1.0/convert["WATTS"]["HP"];
 115     // Force
 116     convert["N"]["LBS"] = 0.22482;
 117     convert["LBS"]["N"] = 1.0/convert["N"]["LBS"];
 118     // Velocity
 119     convert["KTS"]["FT/SEC"] = 1.68781;
 120     convert["FT/SEC"]["KTS"] = 1.0/convert["KTS"]["FT/SEC"];
 121     convert["M/S"]["FT/S"] = 3.2808399;
 122     convert["M/SEC"]["FT/SEC"] = 3.2808399;
 123     convert["FT/S"]["M/S"] = 1.0/convert["M/S"]["FT/S"];
 124     convert["M/SEC"]["FT/SEC"] = 3.2808399;
 125     convert["FT/SEC"]["M/SEC"] = 1.0/convert["M/SEC"]["FT/SEC"];
 126     convert["KM/SEC"]["FT/SEC"] = 3280.8399;
 127     convert["FT/SEC"]["KM/SEC"] = 1.0/convert["KM/SEC"]["FT/SEC"];
 128     // Torque
 129     convert["FT*LBS"]["N*M"] = 1.35581795;
 130     convert["N*M"]["FT*LBS"] = 1/convert["FT*LBS"]["N*M"];
 131     // Valve
 132     convert["M4*SEC/KG"]["FT4*SEC/SLUG"] = convert["M"]["FT"]*convert["M"]["FT"]*
 133       convert["M"]["FT"]*convert["M"]["FT"]/convert["KG"]["SLUG"];
 134     convert["FT4*SEC/SLUG"]["M4*SEC/KG"] =
 135       1.0/convert["M4*SEC/KG"]["FT4*SEC/SLUG"];
 136     // Pressure
 137     convert["INHG"]["PSF"] = 70.7180803;
 138     convert["PSF"]["INHG"] = 1.0/convert["INHG"]["PSF"];
 139     convert["ATM"]["INHG"] = 29.9246899;
 140     convert["INHG"]["ATM"] = 1.0/convert["ATM"]["INHG"];
 141     convert["PSI"]["INHG"] = 2.03625437;
 142     convert["INHG"]["PSI"] = 1.0/convert["PSI"]["INHG"];
 143     convert["INHG"]["PA"] = 3386.0; // inches Mercury to pascals
 144     convert["PA"]["INHG"] = 1.0/convert["INHG"]["PA"];
 145     convert["LBS/FT2"]["N/M2"] = 14.5939/convert["FT"]["M"];
 146     convert["N/M2"]["LBS/FT2"] = 1.0/convert["LBS/FT2"]["N/M2"];
 147     convert["LBS/FT2"]["PA"] = convert["LBS/FT2"]["N/M2"];
 148     convert["PA"]["LBS/FT2"] = 1.0/convert["LBS/FT2"]["PA"];
 149     // Mass flow
 150     convert["KG/MIN"]["LBS/MIN"] = convert["KG"]["LBS"];
 151     // Fuel Consumption
 152     convert["LBS/HP*HR"]["KG/KW*HR"] = 0.6083;
 153     convert["KG/KW*HR"]["LBS/HP*HR"] = 1.0/convert["LBS/HP*HR"]["KG/KW*HR"];
 154     // Density
 155     convert["KG/L"]["LBS/GAL"] = 8.3454045;
 156     convert["LBS/GAL"]["KG/L"] = 1.0/convert["KG/L"]["LBS/GAL"];
 157
 158     // Length
 159     convert["M"]["M"] = 1.00;
 160     convert["KM"]["KM"] = 1.00;
 161     convert["FT"]["FT"] = 1.00;
 162     convert["IN"]["IN"] = 1.00;
 163     // Area
 164     convert["M2"]["M2"] = 1.00;
 165     convert["FT2"]["FT2"] = 1.00;
 166     // Volume
 167     convert["IN3"]["IN3"] = 1.00;
 168     convert["CC"]["CC"] = 1.0;
 169     convert["M3"]["M3"] = 1.0;
 170     convert["FT3"]["FT3"] = 1.0;
 171     convert["LTR"]["LTR"] = 1.0;
 172     // Mass & Weight
 173     convert["KG"]["KG"] = 1.00;
 174     convert["LBS"]["LBS"] = 1.00;
 175     // Moments of Inertia
 176     convert["KG*M2"]["KG*M2"] = 1.00;
 177     convert["SLUG*FT2"]["SLUG*FT2"] = 1.00;
 178     // Angles
 179     convert["DEG"]["DEG"] = 1.00;
 180     convert["RAD"]["RAD"] = 1.00;
 181     // Angular rates
 182     convert["DEG/SEC"]["DEG/SEC"] = 1.00;
 183     convert["RAD/SEC"]["RAD/SEC"] = 1.00;
 184     // Spring force
 185     convert["LBS/FT"]["LBS/FT"] = 1.00;
 186     convert["N/M"]["N/M"] = 1.00;
 187     // Damping force
 188     convert["LBS/FT/SEC"]["LBS/FT/SEC"] = 1.00;
 189     convert["N/M/SEC"]["N/M/SEC"] = 1.00;
 190     // Damping force (Square law)
 191     convert["LBS/FT2/SEC2"]["LBS/FT2/SEC2"] = 1.00;
 192     convert["N/M2/SEC2"]["N/M2/SEC2"] = 1.00;
 193     // Power
 194     convert["HP"]["HP"] = 1.00;
 195     convert["WATTS"]["WATTS"] = 1.00;
 196     // Force
 197     convert["N"]["N"] = 1.00;
 198     // Velocity
 199     convert["FT/SEC"]["FT/SEC"] = 1.00;
 200     convert["KTS"]["KTS"] = 1.00;
 201     convert["M/S"]["M/S"] = 1.0;
 202     convert["M/SEC"]["M/SEC"] = 1.0;
 203     convert["KM/SEC"]["KM/SEC"] = 1.0;
 204     // Torque
 205     convert["FT*LBS"]["FT*LBS"] = 1.00;
 206     convert["N*M"]["N*M"] = 1.00;
 207     // Valve
 208     convert["M4*SEC/KG"]["M4*SEC/KG"] = 1.0;
 209     convert["FT4*SEC/SLUG"]["FT4*SEC/SLUG"] = 1.0;
 210     // Pressure
 211     convert["PSI"]["PSI"] = 1.00;
 212     convert["PSF"]["PSF"] = 1.00;
 213     convert["INHG"]["INHG"] = 1.00;
 214     convert["ATM"]["ATM"] = 1.0;
 215     convert["PA"]["PA"] = 1.0;
 216     convert["N/M2"]["N/M2"] = 1.00;
 217     convert["LBS/FT2"]["LBS/FT2"] = 1.00;
 218     // Mass flow
 219     convert["LBS/SEC"]["LBS/SEC"] = 1.00;
 220     convert["KG/MIN"]["KG/MIN"] = 1.0;
 221     convert["LBS/MIN"]["LBS/MIN"] = 1.0;
 222     // Fuel Consumption
 223     convert["LBS/HP*HR"]["LBS/HP*HR"] = 1.0;
 224     convert["KG/KW*HR"]["KG/KW*HR"] = 1.0;
 225     // Density
 226     convert["KG/L"]["KG/L"] = 1.0;
 227     convert["LBS/GAL"]["LBS/GAL"] = 1.0;
 228   }
 229 }
 230
 231 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 232
 233 Element::~Element(void)
 234 {
 235   for (unsigned int i=0; i<children.size(); i++) delete children[i];
 236   data_lines.clear();
 237   attributes.clear();
 238   attribute_key.clear();
 239 }
 240
 241 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 242
 243 string Element::GetAttributeValue(const string& attr)
 244 {
 245   int select=-1;
 246   for (unsigned int i=0; i<attribute_key.size(); i++) {
 247     if (attribute_key[i] == attr) select = i;
 248   }
 249   if (select < 0) return string("");
 250   else return attributes[attr];
 251 }
 252
 253 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 254
 255 double Element::GetAttributeValueAsNumber(const string& attr)
 256 {
 257   string attribute = GetAttributeValue(attr);
 258
 259   if (attribute.empty()) return HUGE_VAL;
 260   else return (atof(attribute.c_str()));
 261 }
 262
 263 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 264
 265 Element* Element::GetElement(unsigned int el)
 266 {
 267   if (children.size() > el) {
 268     element_index = el;
 269     return children[el];
 270   }
 271   else {
 272     element_index = 0;
 273     return 0L;
 274   }
 275 }
 276
 277 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 278
 279 Element* Element::GetNextElement(void)
 280 {
 281   if (children.size() > element_index+1) {
 282     element_index++;
 283     return children[element_index];
 284   } else {
 285     element_index = 0;
 286     return 0L;
 287   }
 288 }
 289
 290 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 291
 292 string Element::GetDataLine(unsigned int i)
 293 {
 294   if (data_lines.size() > 0) return data_lines[i];
 295   else return string("");
 296 }
 297
 298 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 299
 300 double Element::GetDataAsNumber(void)
 301 {
 302   if (data_lines.size() == 1) {
 303     return atof(data_lines[0].c_str());
 304   } else if (data_lines.size() == 0) {
 305     return HUGE_VAL;
 306   } else {
 307     cerr << "Attempting to get single data value from multiple lines in element " << name << endl;
 308     return HUGE_VAL;
 309   }
 310 }
 311
 312 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 313
 314 unsigned int Element::GetNumElements(const string& element_name)
 315 {
 316   unsigned int number_of_elements=0;
 317   Element* el=FindElement(element_name);
 318   while (el) {
 319     number_of_elements++;
 320     el=FindNextElement(element_name);
 321   }
 322   return number_of_elements;
 323 }
 324
 325 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 326
 327 Element* Element::FindElement(const string& el)
 328 {
 329   if (el.empty() && children.size() >= 1) {
 330     element_index = 1;
 331     return children[0];
 332   }
 333   for (unsigned int i=0; i<children.size(); i++) {
 334     if (el == children[i]->GetName()) {
 335       element_index = i+1;
 336       return children[i];
 337     }
 338   }
 339   element_index = 0;
 340   return 0L;
 341 }
 342
 343 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 344
 345 Element* Element::FindNextElement(const string& el)
 346 {
 347   if (el.empty()) {
 348     if (element_index < children.size()) {
 349       return children[element_index++];
 350     } else {
 351       element_index = 0;
 352       return 0L;
 353     }
 354   }
 355   for (unsigned int i=element_index; i<children.size(); i++) {
 356     if (el == children[i]->GetName()) {
 357       element_index = i+1;
 358       return children[i];
 359     }
 360   }
 361   element_index = 0;
 362   return 0L;
 363 }
 364
 365 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 366
 367 double Element::FindElementValueAsNumber(const string& el)
 368 {
 369   Element* element = FindElement(el);
 370   if (element) {
 371     return element->GetDataAsNumber();
 372   } else {
 373     cerr << "Attempting to get single data value from multiple lines" << endl;
 374     return 0;
 375   }
 376 }
 377
 378 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 379
 380 string Element::FindElementValue(const string& el)
 381 {
 382   Element* element = FindElement(el);
 383   if (element) {
 384     return element->GetDataLine();
 385   } else {
 386     return "";
 387   }
 388 }
 389
 390 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 391
 392 double Element::FindElementValueAsNumberConvertTo(const string& el, const string& target_units)
 393 {
 394   Element* element = FindElement(el);
 395
 396   if (!element) {
 397     cerr << "Attempting to get non-existent element " << el << endl;
 398     exit(0);
 399   }
 400
 401   string supplied_units = element->GetAttributeValue("unit");
 402
 403   if (!supplied_units.empty()) {
 404     if (convert.find(supplied_units) == convert.end()) {
 405       cerr << endl << "Supplied unit: \"" << supplied_units << "\" does not exist (typo?). Add new unit"
 406            << " conversion in FGXMLElement.cpp." << endl;
 407       exit(-1);
 408     }
 409     if (convert[supplied_units].find(target_units) == convert[supplied_units].end()) {
 410       cerr << endl << "Supplied unit: \"" << supplied_units << "\" cannot be converted to "
 411                    << target_units << ". Add new unit conversion in FGXMLElement.cpp or fix typo" << endl;
 412       exit(-1);
 413     }
 414   }
 415
 416   double value = element->GetDataAsNumber();
 417   if (!supplied_units.empty()) {
 418     value *= convert[supplied_units][target_units];
 419   }
 420
 421   return value;
 422 }
 423
 424 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 425
 426 double Element::FindElementValueAsNumberConvertFromTo( const string& el,
 427                                                        const string& supplied_units,
 428                                                        const string& target_units)
 429 {
 430   Element* element = FindElement(el);
 431
 432   if (!element) {
 433     cerr << "Attempting to get non-existent element " << el << endl;
 434     exit(0);
 435   }
 436
 437   if (!supplied_units.empty()) {
 438     if (convert.find(supplied_units) == convert.end()) {
 439       cerr << endl << "Supplied unit: \"" << supplied_units << "\" does not exist (typo?). Add new unit"
 440            << " conversion in FGXMLElement.cpp." << endl;
 441       exit(-1);
 442     }
 443     if (convert[supplied_units].find(target_units) == convert[supplied_units].end()) {
 444       cerr << endl << "Supplied unit: \"" << supplied_units << "\" cannot be converted to "
 445                    << target_units << ". Add new unit conversion in FGXMLElement.cpp or fix typo" << endl;
 446       exit(-1);
 447     }
 448   }
 449
 450   double value = element->GetDataAsNumber();
 451   if (!supplied_units.empty()) {
 452     value *= convert[supplied_units][target_units];
 453   }
 454
 455   return value;
 456 }
 457
 458 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 459
 460 FGColumnVector3 Element::FindElementTripletConvertTo( const string& target_units)
 461 {
 462   FGColumnVector3 triplet;
 463   Element* item;
 464   double value=0.0;
 465   string supplied_units = GetAttributeValue("unit");
 466
 467   if (!supplied_units.empty()) {
 468     if (convert.find(supplied_units) == convert.end()) {
 469       cerr << endl << "Supplied unit: \"" << supplied_units << "\" does not exist (typo?). Add new unit"
 470            << " conversion in FGXMLElement.cpp." << endl;
 471       exit(-1);
 472     }
 473     if (convert[supplied_units].find(target_units) == convert[supplied_units].end()) {
 474       cerr << endl << "Supplied unit: \"" << supplied_units << "\" cannot be converted to "
 475                    << target_units << ". Add new unit conversion in FGXMLElement.cpp or fix typo" << endl;
 476       exit(-1);
 477     }
 478   }
 479
 480   item = FindElement("x");
 481   if (!item) item = FindElement("roll");
 482   if (item) {
 483     value = item->GetDataAsNumber();
 484     if (!supplied_units.empty()) value *= convert[supplied_units][target_units];
 485   } else {
 486     value = 0.0;
 487   }
 488   triplet(1) = value;
 489
 490   item = FindElement("y");
 491   if (!item) item = FindElement("pitch");
 492   if (item) {
 493     value = item->GetDataAsNumber();
 494     if (!supplied_units.empty()) value *= convert[supplied_units][target_units];
 495   } else {
 496     value = 0.0;
 497   }
 498   triplet(2) = value;
 499
 500   item = FindElement("z");
 501   if (!item) item = FindElement("yaw");
 502   if (item) {
 503     value = item->GetDataAsNumber();
 504     if (!supplied_units.empty()) value *= convert[supplied_units][target_units];
 505   } else {
 506     value = 0.0;
 507   }
 508   triplet(3) = value;
 509
 510   return triplet;
 511 }
 512
 513 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 514
 515 void Element::Print(unsigned int level)
 516 {
 517   unsigned int i, spaces;
 518
 519   level+=2;
 520   for (spaces=0; spaces<=level; spaces++) cout << " "; // format output
 521   cout << "Element Name: " << name;
 522   for (i=0; i<attributes.size(); i++) {
 523     cout << "  " << attribute_key[i] << " = " << attributes[attribute_key[i]];
 524   }
 525   cout << endl;
 526   for (i=0; i<data_lines.size(); i++) {
 527     for (spaces=0; spaces<=level; spaces++) cout << " "; // format output
 528     cout << data_lines[i] << endl;
 529   }
 530   for (i=0; i<children.size(); i++) {
 531     children[i]->Print(level);
 532   }
 533 }
 534
 535 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 536
 537 void Element::AddAttribute(const string& name, const string& value)
 538 {
 539   attribute_key.push_back(name);
 540   attributes[name] = value;
 541 }
 542
 543 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 544
 545 void Element::AddData(string d)
 546 {
 547   string::size_type string_start = d.find_first_not_of(" \t");
 548   if (string_start != string::npos && string_start > 0) {
 549     d.erase(0,string_start);
 550   }
 551   data_lines.push_back(d);
 552 }
 553
 554 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 555
 556 } // end namespace JSBSim