libdap++ Updated for version 3.8.2
GridGeoConstraint.cc
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00001 
00002 // -*- mode: c++; c-basic-offset:4 -*-
00003 
00004 // This file is part of libdap, A C++ implementation of the OPeNDAP Data
00005 // Access Protocol.
00006 
00007 // Copyright (c) 2002,2003 OPeNDAP, Inc.
00008 // Author: James Gallagher <jgallagher@opendap.org>
00009 //
00010 // This library is free software; you can redistribute it and/or
00011 // modify it under the terms of the GNU Lesser General Public
00012 // License as published by the Free Software Foundation; either
00013 // version 2.1 of the License, or (at your option) any later version.
00014 //
00015 // This library is distributed in the hope that it will be useful,
00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00018 // Lesser General Public License for more details.
00019 //
00020 // You should have received a copy of the GNU Lesser General Public
00021 // License along with this library; if not, write to the Free Software
00022 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00023 //
00024 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
00025 
00026 // The Grid Selection Expression Clause class.
00027 
00028 
00029 #include "config.h"
00030 
00031 static char id[] not_used =
00032     { "$Id: GridGeoConstraint.cc 24281 2011-03-09 00:22:31Z jimg $"
00033     };
00034 
00035 #include <cmath>
00036 
00037 #include <iostream>
00038 #include <sstream>
00039 
00040 //#define DODS_DEBUG
00041 
00042 #include "debug.h"
00043 #include "dods-datatypes.h"
00044 #include "GridGeoConstraint.h"
00045 #include "Float64.h"
00046 
00047 #include "Error.h"
00048 #include "InternalErr.h"
00049 #include "ce_functions.h"
00050 #include "util.h"
00051 
00052 using namespace std;
00053 
00054 namespace libdap {
00055 
00062 GridGeoConstraint::GridGeoConstraint(Grid *grid)
00063         : GeoConstraint(), d_grid(grid), d_latitude(0), d_longitude(0)
00064 {
00065     if (d_grid->get_array()->dimensions() < 2
00066         || d_grid->get_array()->dimensions() > 3)
00067         throw Error("The geogrid() function works only with Grids of two or three dimensions.");
00068 
00069     // Is this Grid a geo-referenced grid? Throw Error if not.
00070     if (!build_lat_lon_maps())
00071         throw Error(string("The grid '") + d_grid->name()
00072                     + "' does not have identifiable latitude/longitude map vectors.");
00073 
00074     if (!lat_lon_dimensions_ok())
00075         throw Error("The geogrid() function will only work when the Grid's Longitude and Latitude\nmaps are the rightmost dimensions.");
00076 }
00077 
00078 GridGeoConstraint::GridGeoConstraint(Grid *grid, Array *lat, Array *lon)
00079         : GeoConstraint(), d_grid(grid), d_latitude(0), d_longitude(0)
00080 {
00081     if (d_grid->get_array()->dimensions() < 2
00082         || d_grid->get_array()->dimensions() > 3)
00083         throw Error("The geogrid() function works only with Grids of two or three dimensions.");
00084 
00085     // Is this Grid a geo-referenced grid? Throw Error if not.
00086     if (!build_lat_lon_maps(lat, lon))
00087         throw Error(string("The grid '") + d_grid->name()
00088                     + "' does not have valid latitude/longitude map vectors.");
00089 
00090 
00091     if (!lat_lon_dimensions_ok())
00092         throw Error("The geogrid() function will only work when the Grid's Longitude and Latitude\nmaps are the rightmost dimensions.");
00093 }
00094 
00110 bool GridGeoConstraint::build_lat_lon_maps()
00111 {
00112     Grid::Map_iter m = d_grid->map_begin();
00113     // Assume that a Grid is correct and thus has exactly as many maps as its
00114     // array part has dimensions. Thus don't bother to test the Grid's array
00115     // dimension iterator for '!= dim_end()'.
00116     Array::Dim_iter d = d_grid->get_array()->dim_begin();
00117     // The fields d_latitude and d_longitude may be initialized to null or they
00118     // may already contain pointers to the maps to use. In the latter case,
00119     // skip the heuristics used in this code. However, given that all this
00120     // method does is find the lat/lon maps, if they are given in the ctor,
00121     // This method will likely not be called at all.
00122     while (m != d_grid->map_end() && (!d_latitude || !d_longitude)) {
00123         string units_value = (*m)->get_attr_table().get_attr("units");
00124         units_value = remove_quotes(units_value);
00125         string map_name = (*m)->name();
00126 
00127         // The 'units' attribute must match exactly; the name only needs to
00128         // match a prefix.
00129         if (!d_latitude
00130             && unit_or_name_match(get_coards_lat_units(), get_lat_names(),
00131                                   units_value, map_name)) {
00132 
00133             // Set both d_latitude (a pointer to the real map vector) and
00134             // d_lat, a vector of the values represented as doubles. It's easier
00135             // to work with d_lat, but it's d_latitude that needs to be set
00136             // when constraining the grid. Also, record the grid variable's
00137             // dimension iterator so that it's easier to set the Grid's Array
00138             // (which also has to be constrained).
00139             d_latitude = dynamic_cast < Array * >(*m);
00140             if (!d_latitude)
00141                 throw InternalErr(__FILE__, __LINE__, "Expected an array.");
00142             if (!d_latitude->read_p())
00143                 d_latitude->read();
00144 
00145             set_lat(extract_double_array(d_latitude));   // throws Error
00146             set_lat_length(d_latitude->length());
00147 
00148             set_lat_dim(d);
00149         }
00150 
00151         if (!d_longitude        // && !units_value.empty()
00152             && unit_or_name_match(get_coards_lon_units(), get_lon_names(),
00153                                   units_value, map_name)) {
00154 
00155             d_longitude = dynamic_cast < Array * >(*m);
00156             if (!d_longitude)
00157                 throw InternalErr(__FILE__, __LINE__, "Expected an array.");
00158             if (!d_longitude->read_p())
00159                 d_longitude->read();
00160 
00161             set_lon(extract_double_array(d_longitude));
00162             set_lon_length(d_longitude->length());
00163 
00164             set_lon_dim(d);
00165 
00166             if (m + 1 == d_grid->map_end())
00167                 set_longitude_rightmost(true);
00168         }
00169 
00170         ++m;
00171         ++d;
00172     }
00173 
00174     return get_lat() && get_lon();
00175 }
00176 
00184 bool GridGeoConstraint::build_lat_lon_maps(Array *lat, Array *lon)
00185 {
00186     Grid::Map_iter m = d_grid->map_begin();
00187 
00188     Array::Dim_iter d = d_grid->get_array()->dim_begin();
00189 
00190     while (m != d_grid->map_end() && (!d_latitude || !d_longitude)) {
00191         // Look for the Grid map that matches the variable passed as 'lat'
00192         if (!d_latitude && *m == lat) {
00193 
00194             d_latitude = lat;
00195 
00196             if (!d_latitude->read_p())
00197                 d_latitude->read();
00198 
00199             set_lat(extract_double_array(d_latitude));   // throws Error
00200             set_lat_length(d_latitude->length());
00201 
00202             set_lat_dim(d);
00203         }
00204 
00205         if (!d_longitude && *m == lon) {
00206 
00207             d_longitude = lon;
00208 
00209             if (!d_longitude->read_p())
00210                 d_longitude->read();
00211 
00212             set_lon(extract_double_array(d_longitude));
00213             set_lon_length(d_longitude->length());
00214 
00215             set_lon_dim(d);
00216 
00217             if (m + 1 == d_grid->map_end())
00218                 set_longitude_rightmost(true);
00219         }
00220 
00221         ++m;
00222         ++d;
00223     }
00224 
00225     return get_lat() && get_lon();
00226 }
00227 
00238 bool
00239 GridGeoConstraint::lat_lon_dimensions_ok()
00240 {
00241     // get the last two map iterators
00242     Grid::Map_riter rightmost = d_grid->map_rbegin();
00243     Grid::Map_riter next_rightmost = rightmost + 1;
00244 
00245     if (*rightmost == d_longitude && *next_rightmost == d_latitude)
00246         set_longitude_rightmost(true);
00247     else if (*rightmost == d_latitude && *next_rightmost == d_longitude)
00248         set_longitude_rightmost(false);
00249     else
00250         return false;
00251 
00252     return true;
00253 }
00254 
00276 void GridGeoConstraint::apply_constraint_to_data()
00277 {
00278     if (!is_bounding_box_set())
00279         throw InternalErr("The Latitude and Longitude constraints must be set before calling apply_constraint_to_data().");
00280 
00281     Array::Dim_iter fd = d_latitude->dim_begin();
00282 
00283     if (get_latitude_sense() == inverted) {
00284         int tmp = get_latitude_index_top();
00285         set_latitude_index_top(get_latitude_index_bottom());
00286         set_latitude_index_bottom(tmp);
00287     }
00288 
00289     // It's easy to flip the Latitude values; if the bottom index value
00290     // is before/above the top index, return an error explaining that.
00291     if (get_latitude_index_top() > get_latitude_index_bottom())
00292         throw Error("The upper and lower latitude indices appear to be reversed. Please provide the latitude bounding box numbers giving the northern-most latitude first.");
00293 
00294     // Constrain the lat vector and lat dim of the array
00295     d_latitude->add_constraint(fd, get_latitude_index_top(), 1,
00296                                get_latitude_index_bottom());
00297     d_grid->get_array()->add_constraint(get_lat_dim(),
00298                                         get_latitude_index_top(), 1,
00299                                         get_latitude_index_bottom());
00300 
00301     // Does the longitude constraint cross the edge of the longitude vector?
00302     // If so, reorder the grid's data (array), longitude map vector and the
00303     // local vector of longitude data used for computation.
00304     if (get_longitude_index_left() > get_longitude_index_right()) {
00305         reorder_longitude_map(get_longitude_index_left());
00306 
00307         // If the longitude constraint is 'split', join the two parts, reload
00308         // the data into the Grid's Array and make sure the Array is marked as
00309         // already read. This should be true for the whole Grid, but if some
00310         // future modification changes that, the array will be covered here.
00311         // Note that the following method only reads the data out and stores
00312         // it in this object after joining the two parts. The method
00313         // apply_constraint_to_data() transfers the data back from the this
00314         // object to the DAP Grid variable.
00315         reorder_data_longitude_axis(*d_grid->get_array(), get_lon_dim());
00316 
00317         // Now that the data are all in local storage alter the indices; the
00318         // left index has now been moved to 0, and the right index is now
00319         // at lon_vector_length-left+right.
00320         set_longitude_index_right(get_lon_length() - get_longitude_index_left()
00321                                   + get_longitude_index_right());
00322         set_longitude_index_left(0);
00323     }
00324 
00325     // If the constraint used the -180/179 (neg_pos) notation, transform
00326     // the longitude map so it uses the -180/179 notation. Note that at this
00327     // point, d_longitude always uses the pos notation because of the earlier
00328     // conditional transformation.
00329 
00330     // Do this _before_ applying the constraint since set_array_using_double()
00331     // tests the array length using Vector::length() and that method returns
00332     // the length _as constrained_. We want to move all of the longitude
00333     // values from d_lon back into the map, not just the number that will be
00334     // sent (although an optimization might do this, it's hard to imagine
00335     // it would gain much).
00336     if (get_longitude_notation() == neg_pos) {
00337         transform_longitude_to_neg_pos_notation();
00338     }
00339 
00340     // Apply constraint; stride is always one and maps only have one dimension
00341     fd = d_longitude->dim_begin();
00342     d_longitude->add_constraint(fd, get_longitude_index_left(), 1,
00343                                 get_longitude_index_right());
00344 
00345     d_grid->get_array()->add_constraint(get_lon_dim(),
00346                                         get_longitude_index_left(),
00347                                         1, get_longitude_index_right());
00348 
00349     // Transfer values from the local lat vector to the Grid's
00350     // Here test the sense of the latitude vector and invert the vector if the
00351     // sense is 'inverted' so that the top is always the northern-most value
00352     if (get_latitude_sense() == inverted) {
00353         DBG(cerr << "Inverted latitude sense" << endl);
00354         transpose_vector(get_lat() + get_latitude_index_top(),
00355                 get_latitude_index_bottom() - get_latitude_index_top() + 1);
00356         // Now read the Array data and flip the latitudes.
00357         flip_latitude_within_array(*d_grid->get_array(),
00358                 get_latitude_index_bottom() - get_latitude_index_top() + 1,
00359                 get_longitude_index_right() - get_longitude_index_left() + 1);
00360     }
00361 
00362     set_array_using_double(d_latitude, get_lat() + get_latitude_index_top(),
00363                            get_latitude_index_bottom() - get_latitude_index_top() + 1);
00364 
00365     set_array_using_double(d_longitude, get_lon() + get_longitude_index_left(),
00366                            get_longitude_index_right() - get_longitude_index_left() + 1);
00367 
00368     // Look for any non-lat/lon maps and make sure they are read correctly
00369     Grid::Map_iter i = d_grid->map_begin();
00370     Grid::Map_iter end = d_grid->map_end();
00371     while (i != end) {
00372         if (*i != d_latitude && *i != d_longitude) {
00373             if ((*i)->send_p()) {
00374                 DBG(cerr << "reading grid map: " << (*i)->name() << endl);
00375                 //(*i)->set_read_p(false);
00376                 (*i)->read();
00377             }
00378         }
00379         ++i;
00380     }
00381 
00382     // ... and then the Grid's array if it has been read.
00383     if (get_array_data()) {
00384         int size = d_grid->get_array()->val2buf(get_array_data());
00385 
00386         if (size != get_array_data_size())
00387             throw InternalErr(__FILE__, __LINE__, "Expected data size not copied to the Grid's buffer.");
00388 
00389         d_grid->set_read_p(true);
00390     }
00391     else {
00392         d_grid->get_array()->read();
00393     }
00394 }
00395 
00396 } // namespace libdap