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 1.31 2010/09/29 02:22:03 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["FT"]["IN"] = 12.0;
  68     convert["IN"]["FT"] = 1.0/convert["FT"]["IN"];
  69     convert["IN"]["M"] = convert["IN"]["FT"] * convert["FT"]["M"];
  70     convert["M"]["IN"] = convert["M"]["FT"] * convert["FT"]["IN"];
  71     // Area
  72     convert["M2"]["FT2"] = convert["M"]["FT"]*convert["M"]["FT"];
  73     convert["FT2"]["M2"] = 1.0/convert["M2"]["FT2"];
  74     convert["M2"]["IN2"] = convert["M"]["IN"]*convert["M"]["IN"];
  75     convert["IN2"]["M2"] = 1.0/convert["M2"]["IN2"];
  76     convert["FT2"]["IN2"] = 144.0;
  77     convert["IN2"]["FT2"] = 1.0/convert["FT2"]["IN2"];
  78     // Volume
  79     convert["IN3"]["CC"] = 16.387064;
  80     convert["CC"]["IN3"] = 1.0/convert["IN3"]["CC"];
  81     convert["FT3"]["IN3"] = 1728.0;
  82     convert["IN3"]["FT3"] = 1.0/convert["FT3"]["IN3"];
  83     convert["M3"]["FT3"] = 35.3146667;
  84     convert["FT3"]["M3"] = 1.0/convert["M3"]["FT3"];
  85     convert["LTR"]["IN3"] = 61.0237441;
  86     convert["IN3"]["LTR"] = 1.0/convert["LTR"]["IN3"];
  87     // Mass & Weight
  88     convert["LBS"]["KG"] = 0.45359237;
  89     convert["KG"]["LBS"] = 1.0/convert["LBS"]["KG"];
  90     convert["SLUG"]["KG"] = 14.59390;
  91     convert["KG"]["SLUG"] = 1.0/convert["SLUG"]["KG"];
  92     // Moments of Inertia
  93     convert["SLUG*FT2"]["KG*M2"] = 1.35594;
  94     convert["KG*M2"]["SLUG*FT2"] = 1.0/convert["SLUG*FT2"]["KG*M2"];
  95     // Angles
  96     convert["RAD"]["DEG"] = 180.0/M_PI;
  97     convert["DEG"]["RAD"] = 1.0/convert["RAD"]["DEG"];
  98     // Angular rates
  99     convert["RAD/SEC"]["DEG/SEC"] = convert["RAD"]["DEG"];
 100     convert["DEG/SEC"]["RAD/SEC"] = 1.0/convert["RAD/SEC"]["DEG/SEC"];
 101     // Spring force
 102     convert["LBS/FT"]["N/M"] = 14.5939;
 103     convert["N/M"]["LBS/FT"] = 1.0/convert["LBS/FT"]["N/M"];
 104     // Damping force
 105     convert["LBS/FT/SEC"]["N/M/SEC"] = 14.5939;
 106     convert["N/M/SEC"]["LBS/FT/SEC"] = 1.0/convert["LBS/FT/SEC"]["N/M/SEC"];
 107     // Damping force (Square Law)
 108     convert["LBS/FT2/SEC2"]["N/M2/SEC2"] = 47.880259;
 109     convert["N/M2/SEC2"]["LBS/FT2/SEC2"] = 1.0/convert["LBS/FT2/SEC2"]["N/M2/SEC2"];
 110     // Power
 111     convert["WATTS"]["HP"] = 0.001341022;
 112     convert["HP"]["WATTS"] = 1.0/convert["WATTS"]["HP"];
 113     // Force
 114     convert["N"]["LBS"] = 0.22482;
 115     convert["LBS"]["N"] = 1.0/convert["N"]["LBS"];
 116     // Velocity
 117     convert["KTS"]["FT/SEC"] = 1.68781;
 118     convert["FT/SEC"]["KTS"] = 1.0/convert["KTS"]["FT/SEC"];
 119     convert["M/S"]["FT/S"] = 3.2808399;
 120     convert["M/SEC"]["FT/SEC"] = 3.2808399;
 121     convert["FT/S"]["M/S"] = 1.0/convert["M/S"]["FT/S"];
 122     convert["M/SEC"]["FT/SEC"] = 3.2808399;
 123     convert["FT/SEC"]["M/SEC"] = 1.0/convert["M/SEC"]["FT/SEC"];
 124     // Torque
 125     convert["FT*LBS"]["N*M"] = 1.35581795;
 126     convert["N*M"]["FT*LBS"] = 1/convert["FT*LBS"]["N*M"];
 127     // Valve
 128     convert["M4*SEC/KG"]["FT4*SEC/SLUG"] = convert["M"]["FT"]*convert["M"]["FT"]*
 129       convert["M"]["FT"]*convert["M"]["FT"]/convert["KG"]["SLUG"];
 130     convert["FT4*SEC/SLUG"]["M4*SEC/KG"] =
 131       1.0/convert["M4*SEC/KG"]["FT4*SEC/SLUG"];
 132     // Pressure
 133     convert["INHG"]["PSF"] = 70.7180803;
 134     convert["PSF"]["INHG"] = 1.0/convert["INHG"]["PSF"];
 135     convert["ATM"]["INHG"] = 29.9246899;
 136     convert["INHG"]["ATM"] = 1.0/convert["ATM"]["INHG"];
 137     convert["PSI"]["INHG"] = 2.03625437;
 138     convert["INHG"]["PSI"] = 1.0/convert["PSI"]["INHG"];
 139     convert["INHG"]["PA"] = 3386.0; // inches Mercury to pascals
 140     convert["PA"]["INHG"] = 1.0/convert["INHG"]["PA"];
 141     convert["LBS/FT2"]["N/M2"] = 14.5939/convert["FT"]["M"];
 142     convert["N/M2"]["LBS/FT2"] = 1.0/convert["LBS/FT2"]["N/M2"];
 143     convert["LBS/FT2"]["PA"] = convert["LBS/FT2"]["N/M2"];
 144     convert["PA"]["LBS/FT2"] = 1.0/convert["LBS/FT2"]["PA"];
 145     // Mass flow
 146     convert["KG/MIN"]["LBS/MIN"] = convert["KG"]["LBS"];
 147     // Fuel Consumption
 148     convert["LBS/HP*HR"]["KG/KW*HR"] = 0.6083;
 149     convert["KG/KW*HR"]["LBS/HP*HR"] = 1.0/convert["LBS/HP*HR"]["KG/KW*HR"];
 150     // Density
 151     convert["KG/L"]["LBS/GAL"] = 8.3454045;
 152     convert["LBS/GAL"]["KG/L"] = 1.0/convert["KG/L"]["LBS/GAL"];
 153
 154     // Length
 155     convert["M"]["M"] = 1.00;
 156     convert["FT"]["FT"] = 1.00;
 157     convert["IN"]["IN"] = 1.00;
 158     // Area
 159     convert["M2"]["M2"] = 1.00;
 160     convert["FT2"]["FT2"] = 1.00;
 161     // Volume
 162     convert["IN3"]["IN3"] = 1.00;
 163     convert["CC"]["CC"] = 1.0;
 164     convert["M3"]["M3"] = 1.0;
 165     convert["FT3"]["FT3"] = 1.0;
 166     convert["LTR"]["LTR"] = 1.0;
 167     // Mass & Weight
 168     convert["KG"]["KG"] = 1.00;
 169     convert["LBS"]["LBS"] = 1.00;
 170     // Moments of Inertia
 171     convert["KG*M2"]["KG*M2"] = 1.00;
 172     convert["SLUG*FT2"]["SLUG*FT2"] = 1.00;
 173     // Angles
 174     convert["DEG"]["DEG"] = 1.00;
 175     convert["RAD"]["RAD"] = 1.00;
 176     // Angular rates
 177     convert["DEG/SEC"]["DEG/SEC"] = 1.00;
 178     convert["RAD/SEC"]["RAD/SEC"] = 1.00;
 179     // Spring force
 180     convert["LBS/FT"]["LBS/FT"] = 1.00;
 181     convert["N/M"]["N/M"] = 1.00;
 182     // Damping force
 183     convert["LBS/FT/SEC"]["LBS/FT/SEC"] = 1.00;
 184     convert["N/M/SEC"]["N/M/SEC"] = 1.00;
 185     // Damping force (Square law)
 186     convert["LBS/FT2/SEC2"]["LBS/FT2/SEC2"] = 1.00;
 187     convert["N/M2/SEC2"]["N/M2/SEC2"] = 1.00;
 188     // Power
 189     convert["HP"]["HP"] = 1.00;
 190     convert["WATTS"]["WATTS"] = 1.00;
 191     // Force
 192     convert["N"]["N"] = 1.00;
 193     // Velocity
 194     convert["FT/SEC"]["FT/SEC"] = 1.00;
 195     convert["KTS"]["KTS"] = 1.00;
 196     convert["M/S"]["M/S"] = 1.0;
 197     convert["M/SEC"]["M/SEC"] = 1.0;
 198     // Torque
 199     convert["FT*LBS"]["FT*LBS"] = 1.00;
 200     convert["N*M"]["N*M"] = 1.00;
 201     // Valve
 202     convert["M4*SEC/KG"]["M4*SEC/KG"] = 1.0;
 203     convert["FT4*SEC/SLUG"]["FT4*SEC/SLUG"] = 1.0;
 204     // Pressure
 205     convert["PSI"]["PSI"] = 1.00;
 206     convert["PSF"]["PSF"] = 1.00;
 207     convert["INHG"]["INHG"] = 1.00;
 208     convert["ATM"]["ATM"] = 1.0;
 209     convert["PA"]["PA"] = 1.0;
 210     convert["N/M2"]["N/M2"] = 1.00;
 211     convert["LBS/FT2"]["LBS/FT2"] = 1.00;
 212     // Mass flow
 213     convert["LBS/SEC"]["LBS/SEC"] = 1.00;
 214     convert["KG/MIN"]["KG/MIN"] = 1.0;
 215     convert["LBS/MIN"]["LBS/MIN"] = 1.0;
 216     // Fuel Consumption
 217     convert["LBS/HP*HR"]["LBS/HP*HR"] = 1.0;
 218     convert["KG/KW*HR"]["KG/KW*HR"] = 1.0;
 219     // Density
 220     convert["KG/L"]["KG/L"] = 1.0;
 221     convert["LBS/GAL"]["LBS/GAL"] = 1.0;
 222   }
 223 }
 224
 225 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 226
 227 Element::~Element(void)
 228 {
 229   for (unsigned int i=0; i<children.size(); i++) delete children[i];
 230   data_lines.clear();
 231   attributes.clear();
 232   attribute_key.clear();
 233 }
 234
 235 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 236
 237 string Element::GetAttributeValue(const string& attr)
 238 {
 239   int select=-1;
 240   for (unsigned int i=0; i<attribute_key.size(); i++) {
 241     if (attribute_key[i] == attr) select = i;
 242   }
 243   if (select < 0) return string("");
 244   else return attributes[attr];
 245 }
 246
 247 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 248
 249 double Element::GetAttributeValueAsNumber(const string& attr)
 250 {
 251   string attribute = GetAttributeValue(attr);
 252
 253   if (attribute.empty()) return HUGE_VAL;
 254   else return (atof(attribute.c_str()));
 255 }
 256
 257 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 258
 259 Element* Element::GetElement(unsigned int el)
 260 {
 261   if (children.size() > el) {
 262     element_index = el;
 263     return children[el];
 264   }
 265   else {
 266     element_index = 0;
 267     return 0L;
 268   }
 269 }
 270
 271 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 272
 273 Element* Element::GetNextElement(void)
 274 {
 275   if (children.size() > element_index+1) {
 276     element_index++;
 277     return children[element_index];
 278   } else {
 279     element_index = 0;
 280     return 0L;
 281   }
 282 }
 283
 284 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 285
 286 string Element::GetDataLine(unsigned int i)
 287 {
 288   if (data_lines.size() > 0) return data_lines[i];
 289   else return string("");
 290 }
 291
 292 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 293
 294 double Element::GetDataAsNumber(void)
 295 {
 296   if (data_lines.size() == 1) {
 297     return atof(data_lines[0].c_str());
 298   } else if (data_lines.size() == 0) {
 299     return HUGE_VAL;
 300   } else {
 301     cerr << "Attempting to get single data value from multiple lines in element " << name << endl;
 302     return HUGE_VAL;
 303   }
 304 }
 305
 306 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 307
 308 unsigned int Element::GetNumElements(const string& element_name)
 309 {
 310   unsigned int number_of_elements=0;
 311   Element* el=FindElement(element_name);
 312   while (el) {
 313     number_of_elements++;
 314     el=FindNextElement(element_name);
 315   }
 316   return number_of_elements;
 317 }
 318
 319 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 320
 321 Element* Element::FindElement(const string& el)
 322 {
 323   if (el.empty() && children.size() >= 1) {
 324     element_index = 1;
 325     return children[0];
 326   }
 327   for (unsigned int i=0; i<children.size(); i++) {
 328     if (el == children[i]->GetName()) {
 329       element_index = i+1;
 330       return children[i];
 331     }
 332   }
 333   element_index = 0;
 334   return 0L;
 335 }
 336
 337 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 338
 339 Element* Element::FindNextElement(const string& el)
 340 {
 341   if (el.empty()) {
 342     if (element_index < children.size()) {
 343       return children[element_index++];
 344     } else {
 345       element_index = 0;
 346       return 0L;
 347     }
 348   }
 349   for (unsigned int i=element_index; i<children.size(); i++) {
 350     if (el == children[i]->GetName()) {
 351       element_index = i+1;
 352       return children[i];
 353     }
 354   }
 355   element_index = 0;
 356   return 0L;
 357 }
 358
 359 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 360
 361 double Element::FindElementValueAsNumber(const string& el)
 362 {
 363   Element* element = FindElement(el);
 364   if (element) {
 365     return element->GetDataAsNumber();
 366   } else {
 367     cerr << "Attempting to get single data value from multiple lines" << endl;
 368     return 0;
 369   }
 370 }
 371
 372 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 373
 374 string Element::FindElementValue(const string& el)
 375 {
 376   Element* element = FindElement(el);
 377   if (element) {
 378     return element->GetDataLine();
 379   } else {
 380     return "";
 381   }
 382 }
 383
 384 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 385
 386 double Element::FindElementValueAsNumberConvertTo(const string& el, const string& target_units)
 387 {
 388   Element* element = FindElement(el);
 389
 390   if (!element) {
 391     cerr << "Attempting to get non-existent element " << el << endl;
 392     exit(0);
 393   }
 394
 395   string supplied_units = element->GetAttributeValue("unit");
 396
 397   if (!supplied_units.empty()) {
 398     if (convert.find(supplied_units) == convert.end()) {
 399       cerr << endl << "Supplied unit: \"" << supplied_units << "\" does not exist (typo?). Add new unit"
 400            << " conversion in FGXMLElement.cpp." << endl;
 401       exit(-1);
 402     }
 403     if (convert[supplied_units].find(target_units) == convert[supplied_units].end()) {
 404       cerr << endl << "Supplied unit: \"" << supplied_units << "\" cannot be converted to "
 405                    << target_units << ". Add new unit conversion in FGXMLElement.cpp or fix typo" << endl;
 406       exit(-1);
 407     }
 408   }
 409
 410   double value = element->GetDataAsNumber();
 411   if (!supplied_units.empty()) {
 412     value *= convert[supplied_units][target_units];
 413   }
 414
 415   return value;
 416 }
 417
 418 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 419
 420 double Element::FindElementValueAsNumberConvertFromTo( const string& el,
 421                                                        const string& supplied_units,
 422                                                        const string& target_units)
 423 {
 424   Element* element = FindElement(el);
 425
 426   if (!element) {
 427     cerr << "Attempting to get non-existent element " << el << endl;
 428     exit(0);
 429   }
 430
 431   if (!supplied_units.empty()) {
 432     if (convert.find(supplied_units) == convert.end()) {
 433       cerr << endl << "Supplied unit: \"" << supplied_units << "\" does not exist (typo?). Add new unit"
 434            << " conversion in FGXMLElement.cpp." << endl;
 435       exit(-1);
 436     }
 437     if (convert[supplied_units].find(target_units) == convert[supplied_units].end()) {
 438       cerr << endl << "Supplied unit: \"" << supplied_units << "\" cannot be converted to "
 439                    << target_units << ". Add new unit conversion in FGXMLElement.cpp or fix typo" << endl;
 440       exit(-1);
 441     }
 442   }
 443
 444   double value = element->GetDataAsNumber();
 445   if (!supplied_units.empty()) {
 446     value *= convert[supplied_units][target_units];
 447   }
 448
 449   return value;
 450 }
 451
 452 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 453
 454 FGColumnVector3 Element::FindElementTripletConvertTo( const string& target_units)
 455 {
 456   FGColumnVector3 triplet;
 457   Element* item;
 458   double value=0.0;
 459   string supplied_units = GetAttributeValue("unit");
 460
 461   if (!supplied_units.empty()) {
 462     if (convert.find(supplied_units) == convert.end()) {
 463       cerr << endl << "Supplied unit: \"" << supplied_units << "\" does not exist (typo?). Add new unit"
 464            << " conversion in FGXMLElement.cpp." << endl;
 465       exit(-1);
 466     }
 467     if (convert[supplied_units].find(target_units) == convert[supplied_units].end()) {
 468       cerr << endl << "Supplied unit: \"" << supplied_units << "\" cannot be converted to "
 469                    << target_units << ". Add new unit conversion in FGXMLElement.cpp or fix typo" << endl;
 470       exit(-1);
 471     }
 472   }
 473
 474   item = FindElement("x");
 475   if (!item) item = FindElement("roll");
 476   if (item) {
 477     value = item->GetDataAsNumber();
 478     if (!supplied_units.empty()) value *= convert[supplied_units][target_units];
 479   } else {
 480     value = 0.0;
 481   }
 482   triplet(1) = value;
 483
 484   item = FindElement("y");
 485   if (!item) item = FindElement("pitch");
 486   if (item) {
 487     value = item->GetDataAsNumber();
 488     if (!supplied_units.empty()) value *= convert[supplied_units][target_units];
 489   } else {
 490     value = 0.0;
 491   }
 492   triplet(2) = value;
 493
 494   item = FindElement("z");
 495   if (!item) item = FindElement("yaw");
 496   if (item) {
 497     value = item->GetDataAsNumber();
 498     if (!supplied_units.empty()) value *= convert[supplied_units][target_units];
 499   } else {
 500     value = 0.0;
 501   }
 502   triplet(3) = value;
 503
 504   return triplet;
 505 }
 506
 507 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 508
 509 void Element::Print(unsigned int level)
 510 {
 511   unsigned int i, spaces;
 512
 513   level+=2;
 514   for (spaces=0; spaces<=level; spaces++) cout << " "; // format output
 515   cout << "Element Name: " << name;
 516   for (i=0; i<attributes.size(); i++) {
 517     cout << "  " << attribute_key[i] << " = " << attributes[attribute_key[i]];
 518   }
 519   cout << endl;
 520   for (i=0; i<data_lines.size(); i++) {
 521     for (spaces=0; spaces<=level; spaces++) cout << " "; // format output
 522     cout << data_lines[i] << endl;
 523   }
 524   for (i=0; i<children.size(); i++) {
 525     children[i]->Print(level);
 526   }
 527 }
 528
 529 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 530
 531 void Element::AddAttribute(const string& name, const string& value)
 532 {
 533   attribute_key.push_back(name);
 534   attributes[name] = value;
 535 }
 536
 537 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 538
 539 void Element::AddData(string d)
 540 {
 541   string::size_type string_start = d.find_first_not_of(" \t");
 542   if (string_start != string::npos && string_start > 0) {
 543     d.erase(0,string_start);
 544   }
 545   data_lines.push_back(d);
 546 }
 547
 548 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 549
 550 } // end namespace JSBSim