GeographicLib  2.1.2
Gravity.cpp
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1 /**
2  * \file Gravity.cpp
3  * \brief Command line utility for evaluating gravity fields
4  *
5  * Copyright (c) Charles Karney (2011-2022) <charles@karney.com> and licensed
6  * under the MIT/X11 License. For more information, see
7  * https://geographiclib.sourceforge.io/
8  *
9  * See the <a href="Gravity.1.html">man page</a> for usage information.
10  **********************************************************************/
11 
12 #include <iostream>
13 #include <string>
14 #include <sstream>
15 #include <fstream>
18 #include <GeographicLib/DMS.hpp>
20 
21 #if defined(_MSC_VER)
22 // Squelch warnings about constant conditional and enum-float expressions
23 // and potentially uninitialized local variables
24 # pragma warning (disable: 4127 5055 4701)
25 #endif
26 
27 #include "Gravity.usage"
28 
29 int main(int argc, const char* const argv[]) {
30  try {
31  using namespace GeographicLib;
32  typedef Math::real real;
34  bool verbose = false, longfirst = false;
35  std::string dir;
36  std::string model = GravityModel::DefaultGravityName();
37  std::string istring, ifile, ofile, cdelim;
38  char lsep = ';';
39  real lat = 0, h = 0;
40  bool circle = false;
41  int prec = -1, Nmax = -1, Mmax = -1;
42  enum {
43  GRAVITY = 0,
44  DISTURBANCE = 1,
45  ANOMALY = 2,
46  UNDULATION = 3,
47  };
48  unsigned mode = GRAVITY;
49  for (int m = 1; m < argc; ++m) {
50  std::string arg(argv[m]);
51  if (arg == "-n") {
52  if (++m == argc) return usage(1, true);
53  model = argv[m];
54  } else if (arg == "-d") {
55  if (++m == argc) return usage(1, true);
56  dir = argv[m];
57  } else if (arg == "-N") {
58  if (++m == argc) return usage(1, true);
59  try {
60  Nmax = Utility::val<int>(std::string(argv[m]));
61  if (Nmax < 0) {
62  std::cerr << "Maximum degree " << argv[m] << " is negative\n";
63  return 1;
64  }
65  }
66  catch (const std::exception&) {
67  std::cerr << "Precision " << argv[m] << " is not a number\n";
68  return 1;
69  }
70  } else if (arg == "-M") {
71  if (++m == argc) return usage(1, true);
72  try {
73  Mmax = Utility::val<int>(std::string(argv[m]));
74  if (Mmax < 0) {
75  std::cerr << "Maximum order " << argv[m] << " is negative\n";
76  return 1;
77  }
78  }
79  catch (const std::exception&) {
80  std::cerr << "Precision " << argv[m] << " is not a number\n";
81  return 1;
82  }
83  } else if (arg == "-G")
84  mode = GRAVITY;
85  else if (arg == "-D")
86  mode = DISTURBANCE;
87  else if (arg == "-A")
88  mode = ANOMALY;
89  else if (arg == "-H")
90  mode = UNDULATION;
91  else if (arg == "-c") {
92  if (m + 2 >= argc) return usage(1, true);
93  try {
94  using std::fabs;
95  DMS::flag ind;
96  lat = DMS::Decode(std::string(argv[++m]), ind);
97  if (ind == DMS::LONGITUDE)
98  throw GeographicErr("Bad hemisphere letter on latitude");
99  if (!(fabs(lat) <= Math::qd))
100  throw GeographicErr("Latitude not in [-" + std::to_string(Math::qd)
101  + "d, " + std::to_string(Math::qd) + "d]");
102  h = Utility::val<real>(std::string(argv[++m]));
103  circle = true;
104  }
105  catch (const std::exception& e) {
106  std::cerr << "Error decoding argument of " << arg << ": "
107  << e.what() << "\n";
108  return 1;
109  }
110  } else if (arg == "-w")
111  longfirst = !longfirst;
112  else if (arg == "-p") {
113  if (++m == argc) return usage(1, true);
114  try {
115  prec = Utility::val<int>(std::string(argv[m]));
116  }
117  catch (const std::exception&) {
118  std::cerr << "Precision " << argv[m] << " is not a number\n";
119  return 1;
120  }
121  } else if (arg == "-v")
122  verbose = true;
123  else if (arg == "--input-string") {
124  if (++m == argc) return usage(1, true);
125  istring = argv[m];
126  } else if (arg == "--input-file") {
127  if (++m == argc) return usage(1, true);
128  ifile = argv[m];
129  } else if (arg == "--output-file") {
130  if (++m == argc) return usage(1, true);
131  ofile = argv[m];
132  } else if (arg == "--line-separator") {
133  if (++m == argc) return usage(1, true);
134  if (std::string(argv[m]).size() != 1) {
135  std::cerr << "Line separator must be a single character\n";
136  return 1;
137  }
138  lsep = argv[m][0];
139  } else if (arg == "--comment-delimiter") {
140  if (++m == argc) return usage(1, true);
141  cdelim = argv[m];
142  } else if (arg == "--version") {
143  std::cout << argv[0] << ": GeographicLib version "
144  << GEOGRAPHICLIB_VERSION_STRING << "\n";
145  return 0;
146  } else {
147  int retval = usage(!(arg == "-h" || arg == "--help"), arg != "--help");
148  if (arg == "-h")
149  std::cout<< "\nDefault gravity path = \""
151  << "\"\nDefault gravity name = \""
153  << "\"\n";
154  return retval;
155  }
156  }
157 
158  if (!ifile.empty() && !istring.empty()) {
159  std::cerr << "Cannot specify --input-string and --input-file together\n";
160  return 1;
161  }
162  if (ifile == "-") ifile.clear();
163  std::ifstream infile;
164  std::istringstream instring;
165  if (!ifile.empty()) {
166  infile.open(ifile.c_str());
167  if (!infile.is_open()) {
168  std::cerr << "Cannot open " << ifile << " for reading\n";
169  return 1;
170  }
171  } else if (!istring.empty()) {
172  std::string::size_type m = 0;
173  while (true) {
174  m = istring.find(lsep, m);
175  if (m == std::string::npos)
176  break;
177  istring[m] = '\n';
178  }
179  instring.str(istring);
180  }
181  std::istream* input = !ifile.empty() ? &infile :
182  (!istring.empty() ? &instring : &std::cin);
183 
184  std::ofstream outfile;
185  if (ofile == "-") ofile.clear();
186  if (!ofile.empty()) {
187  outfile.open(ofile.c_str());
188  if (!outfile.is_open()) {
189  std::cerr << "Cannot open " << ofile << " for writing\n";
190  return 1;
191  }
192  }
193  std::ostream* output = !ofile.empty() ? &outfile : &std::cout;
194 
195  switch (mode) {
196  case GRAVITY:
197  prec = std::min(16 + Math::extra_digits(), prec < 0 ? 5 : prec);
198  break;
199  case DISTURBANCE:
200  case ANOMALY:
201  prec = std::min(14 + Math::extra_digits(), prec < 0 ? 3 : prec);
202  break;
203  case UNDULATION:
204  default:
205  prec = std::min(12 + Math::extra_digits(), prec < 0 ? 4 : prec);
206  break;
207  }
208  int retval = 0;
209  try {
210  using std::isfinite;
211  const GravityModel g(model, dir, Nmax, Mmax);
212  if (circle) {
213  if (!isfinite(h))
214  throw GeographicErr("Bad height");
215  else if (mode == UNDULATION && h != 0)
216  throw GeographicErr("Height should be zero for geoid undulations");
217  }
218  if (verbose) {
219  std::cerr << "Gravity file: " << g.GravityFile() << "\n"
220  << "Name: " << g.GravityModelName() << "\n"
221  << "Description: " << g.Description() << "\n"
222  << "Date & Time: " << g.DateTime() << "\n";
223  }
224  unsigned mask = (mode == GRAVITY ? GravityModel::GRAVITY :
225  (mode == DISTURBANCE ? GravityModel::DISTURBANCE :
226  (mode == ANOMALY ? GravityModel::SPHERICAL_ANOMALY :
227  GravityModel::GEOID_HEIGHT))); // mode == UNDULATION
228  const GravityCircle c(circle ? g.Circle(lat, h, mask) : GravityCircle());
229  std::string s, eol, stra, strb;
230  std::istringstream str;
231  while (std::getline(*input, s)) {
232  try {
233  eol = "\n";
234  if (!cdelim.empty()) {
235  std::string::size_type m = s.find(cdelim);
236  if (m != std::string::npos) {
237  eol = " " + s.substr(m) + "\n";
238  s = s.substr(0, m);
239  }
240  }
241  str.clear(); str.str(s);
242  real lon;
243  if (circle) {
244  if (!(str >> strb))
245  throw GeographicErr("Incomplete input: " + s);
246  DMS::flag ind;
247  lon = DMS::Decode(strb, ind);
248  if (ind == DMS::LATITUDE)
249  throw GeographicErr("Bad hemisphere letter on " + strb);
250  } else {
251  if (!(str >> stra >> strb))
252  throw GeographicErr("Incomplete input: " + s);
253  DMS::DecodeLatLon(stra, strb, lat, lon, longfirst);
254  h = 0;
255  if (!(str >> h)) // h is optional
256  str.clear();
257  if (mode == UNDULATION && h != 0)
258  throw GeographicErr("Height must be zero for geoid heights");
259  }
260  if (str >> stra)
261  throw GeographicErr("Extra junk in input: " + s);
262  switch (mode) {
263  case GRAVITY:
264  {
265  real gx, gy, gz;
266  if (circle) {
267  c.Gravity(lon, gx, gy, gz);
268  } else {
269  g.Gravity(lat, lon, h, gx, gy, gz);
270  }
271  *output << Utility::str(gx, prec) << " "
272  << Utility::str(gy, prec) << " "
273  << Utility::str(gz, prec) << eol;
274  }
275  break;
276  case DISTURBANCE:
277  {
278  real deltax, deltay, deltaz;
279  if (circle) {
280  c.Disturbance(lon, deltax, deltay, deltaz);
281  } else {
282  g.Disturbance(lat, lon, h, deltax, deltay, deltaz);
283  }
284  // Convert to mGals
285  *output << Utility::str(deltax * 100000, prec) << " "
286  << Utility::str(deltay * 100000, prec) << " "
287  << Utility::str(deltaz * 100000, prec)
288  << eol;
289  }
290  break;
291  case ANOMALY:
292  {
293  real Dg01, xi, eta;
294  if (circle)
295  c.SphericalAnomaly(lon, Dg01, xi, eta);
296  else
297  g.SphericalAnomaly(lat, lon, h, Dg01, xi, eta);
298  Dg01 *= 100000; // Convert to mGals
299  xi *= Math::ds; // Convert to arcsecs
300  eta *= Math::ds;
301  *output << Utility::str(Dg01, prec) << " "
302  << Utility::str(xi, prec) << " "
303  << Utility::str(eta, prec) << eol;
304  }
305  break;
306  case UNDULATION:
307  default:
308  {
309  real N = circle ? c.GeoidHeight(lon) : g.GeoidHeight(lat, lon);
310  *output << Utility::str(N, prec) << eol;
311  }
312  break;
313  }
314  }
315  catch (const std::exception& e) {
316  *output << "ERROR: " << e.what() << "\n";
317  retval = 1;
318  }
319  }
320  }
321  catch (const std::exception& e) {
322  std::cerr << "Error reading " << model << ": " << e.what() << "\n";
323  retval = 1;
324  }
325  return retval;
326  }
327  catch (const std::exception& e) {
328  std::cerr << "Caught exception: " << e.what() << "\n";
329  return 1;
330  }
331  catch (...) {
332  std::cerr << "Caught unknown exception\n";
333  return 1;
334  }
335 }
Header for GeographicLib::DMS class.
GeographicLib::Math::real real
Definition: GeodSolve.cpp:31
Header for GeographicLib::GravityCircle class.
Header for GeographicLib::GravityModel class.
int main(int argc, const char *const argv[])
Definition: Gravity.cpp:29
Header for GeographicLib::Utility class.
static void DecodeLatLon(const std::string &dmsa, const std::string &dmsb, real &lat, real &lon, bool longfirst=false)
Definition: DMS.cpp:368
static Math::real Decode(const std::string &dms, flag &ind)
Definition: DMS.cpp:40
Exception handling for GeographicLib.
Definition: Constants.hpp:316
Gravity on a circle of latitude.
Math::real Gravity(real lon, real &gx, real &gy, real &gz) const
Math::real Disturbance(real lon, real &deltax, real &deltay, real &deltaz) const
Math::real GeoidHeight(real lon) const
void SphericalAnomaly(real lon, real &Dg01, real &xi, real &eta) const
Model of the earth's gravity field.
const std::string & DateTime() const
Math::real Disturbance(real lat, real lon, real h, real &deltax, real &deltay, real &deltaz) const
static std::string DefaultGravityPath()
void SphericalAnomaly(real lat, real lon, real h, real &Dg01, real &xi, real &eta) const
GravityCircle Circle(real lat, real h, unsigned caps=ALL) const
static std::string DefaultGravityName()
Math::real GeoidHeight(real lat, real lon) const
const std::string & GravityFile() const
Math::real Gravity(real lat, real lon, real h, real &gx, real &gy, real &gz) const
const std::string & Description() const
const std::string & GravityModelName() const
@ ds
seconds per degree
Definition: Math.hpp:146
@ qd
degrees per quarter turn
Definition: Math.hpp:141
static int extra_digits()
Definition: Math.cpp:51
static int set_digits(int ndigits=0)
Definition: Utility.cpp:184
static std::string str(T x, int p=-1)
Definition: Utility.hpp:161
Namespace for GeographicLib.
Definition: Accumulator.cpp:12