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 21922 2010-01-07 18:23:57Z 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 
00064 GridGeoConstraint::GridGeoConstraint(Grid *grid)
00065         : GeoConstraint(), d_grid(grid), d_latitude(0), d_longitude(0)
00066 {
00067     if (d_grid->get_array()->dimensions() < 2
00068         || d_grid->get_array()->dimensions() > 3)
00069         throw Error("The geogrid() function works only with Grids of two or three dimensions.");
00070 
00071     // Is this Grid a geo-referenced grid? Throw Error if not.
00072     if (!build_lat_lon_maps())
00073         throw Error(string("The grid '") + d_grid->name()
00074                     +
00075                     "' does not have identifiable latitude/longitude map vectors.");
00076 
00077     if (!lat_lon_dimensions_ok())
00078         throw Error("The geogrid() function will only work when the Grid's Longitude and Latitude\nmaps are the rightmost dimensions.");
00079 }
00080 
00096 bool GridGeoConstraint::build_lat_lon_maps()
00097 {
00098     Grid::Map_iter m = d_grid->map_begin();
00099     // Assume that a Grid is correct and thus has exactly as many maps at its
00100     // array part has dimensions. Thus don't bother to test the Grid's array
00101     // dimension iterator for '!= dim_end()'.
00102     Array::Dim_iter d = d_grid->get_array()->dim_begin();
00103     // The fields d_latitude and d_longitude are initialized to null
00104     while (m != d_grid->map_end() && (!d_latitude || !d_longitude)) {
00105         string units_value = (*m)->get_attr_table().get_attr("units");
00106         units_value = remove_quotes(units_value);
00107         string map_name = (*m)->name();
00108 
00109         // The 'units' attribute must match exactly; the name only needs to
00110         // match a prefix.
00111         if (!d_latitude
00112             && unit_or_name_match(get_coards_lat_units(), get_lat_names(),
00113                                   units_value, map_name)) {
00114 
00115             // Set both d_latitude (a pointer to the real map vector) and
00116             // d_lat, a vector of the values represented as doubles. It's easier
00117             // to work with d_lat, but it's d_latitude that needs to be set
00118             // when constraining the grid. Also, record the grid variable's
00119             // dimension iterator so that it's easier to set the Grid's Array
00120             // (which also has to be constrained).
00121             d_latitude = dynamic_cast < Array * >(*m);
00122             if (!d_latitude)
00123                 throw InternalErr(__FILE__, __LINE__, "Expected an array.");
00124             if (!d_latitude->read_p())
00125                 d_latitude->read();
00126 
00127             set_lat(extract_double_array(d_latitude));   // throws Error
00128             set_lat_length(d_latitude->length());
00129 
00130             set_lat_dim(d);
00131         }
00132 
00133         if (!d_longitude        // && !units_value.empty()
00134             && unit_or_name_match(get_coards_lon_units(), get_lon_names(),
00135                                   units_value, map_name)) {
00136 
00137             d_longitude = dynamic_cast < Array * >(*m);
00138             if (!d_longitude)
00139                 throw InternalErr(__FILE__, __LINE__, "Expected an array.");
00140             if (!d_longitude->read_p())
00141                 d_longitude->read();
00142 
00143             set_lon(extract_double_array(d_longitude));
00144             set_lon_length(d_longitude->length());
00145 
00146             set_lon_dim(d);
00147 
00148             if (m + 1 == d_grid->map_end())
00149                 set_longitude_rightmost(true);
00150         }
00151 
00152         ++m;
00153         ++d;
00154     }
00155 
00156     return get_lat() && get_lon();
00157 }
00158 
00169 bool
00170 GridGeoConstraint::lat_lon_dimensions_ok()
00171 {
00172     // get the last two map iterators
00173     Grid::Map_riter rightmost = d_grid->map_rbegin();
00174     Grid::Map_riter next_rightmost = rightmost + 1;
00175 
00176     if (*rightmost == d_longitude && *next_rightmost == d_latitude)
00177         set_longitude_rightmost(true);
00178     else if (*rightmost == d_latitude && *next_rightmost == d_longitude)
00179         set_longitude_rightmost(false);
00180     else
00181         return false;
00182 
00183     return true;
00184 }
00185 
00207 void GridGeoConstraint::apply_constraint_to_data()
00208 {
00209     if (!is_bounding_box_set())
00210         throw InternalErr("The Latitude and Longitude constraints must be set before calling apply_constraint_to_data().");
00211 
00212     Array::Dim_iter fd = d_latitude->dim_begin();
00213 
00214     if (get_latitude_sense() == inverted) {
00215         int tmp = get_latitude_index_top();
00216         set_latitude_index_top(get_latitude_index_bottom());
00217         set_latitude_index_bottom(tmp);
00218     }
00219 
00220     // It's easy to flip the Latitude values; if the bottom index value
00221     // is before/above the top index, return an error explaining that.
00222     if (get_latitude_index_top() > get_latitude_index_bottom())
00223         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.");
00224 
00225     // Constrain the lat vector and lat dim of the array
00226     d_latitude->add_constraint(fd, get_latitude_index_top(), 1,
00227                                get_latitude_index_bottom());
00228     d_grid->get_array()->add_constraint(get_lat_dim(),
00229                                         get_latitude_index_top(), 1,
00230                                         get_latitude_index_bottom());
00231 
00232     // Does the longitude constraint cross the edge of the longitude vector?
00233     // If so, reorder the grid's data (array), longitude map vector and the
00234     // local vector of longitude data used for computation.
00235     if (get_longitude_index_left() > get_longitude_index_right()) {
00236         reorder_longitude_map(get_longitude_index_left());
00237 
00238         // If the longitude constraint is 'split', join the two parts, reload
00239         // the data into the Grid's Array and make sure the Array is marked as
00240         // already read. This should be true for the whole Grid, but if some
00241         // future modification changes that, the array will be covered here.
00242         // Note that the following method only reads the data out and stores
00243         // it in this object after joining the two parts. The method
00244         // apply_constraint_to_data() transfers the data back from the this
00245         // object to the DAP Grid variable.
00246         reorder_data_longitude_axis(*d_grid->get_array(), get_lon_dim());
00247 
00248         // Now that the data are all in local storage alter the indices; the
00249         // left index has now been moved to 0, and the right index is now
00250         // at lon_vector_length-left+right.
00251         set_longitude_index_right(get_lon_length() - get_longitude_index_left()
00252                                   + get_longitude_index_right());
00253         set_longitude_index_left(0);
00254     }
00255 
00256     // If the constraint used the -180/179 (neg_pos) notation, transform
00257     // the longitude map so it uses the -180/179 notation. Note that at this
00258     // point, d_longitude always uses the pos notation because of the earlier
00259     // conditional transformation.
00260 
00261     // Do this _before_ applying the constraint since set_array_using_double()
00262     // tests the array length using Vector::length() and that method returns
00263     // the length _as constrained_. We want to move all of the longitude
00264     // values from d_lon back into the map, not just the number that will be
00265     // sent (although an optimization might do this, it's hard to imagine
00266     // it would gain much).
00267     if (get_longitude_notation() == neg_pos) {
00268         transform_longitude_to_neg_pos_notation();
00269     }
00270 
00271     // Apply constraint; stride is always one and maps only have one dimension
00272     fd = d_longitude->dim_begin();
00273     d_longitude->add_constraint(fd, get_longitude_index_left(), 1,
00274                                 get_longitude_index_right());
00275 
00276     d_grid->get_array()->add_constraint(get_lon_dim(),
00277                                         get_longitude_index_left(),
00278                                         1, get_longitude_index_right());
00279 
00280     // Transfer values from the local lat vector to the Grid's
00281     // Here test the sense of the latitude vector and invert the vector if the
00282     // sense is 'inverted' so that the top is always the northern-most value
00283     if (get_latitude_sense() == inverted) {
00284         DBG(cerr << "Inverted latitude sense" << endl);
00285         transpose_vector(get_lat() + get_latitude_index_top(),
00286                 get_latitude_index_bottom() - get_latitude_index_top() + 1);
00287         // Now read the Array data and flip the latitudes.
00288         flip_latitude_within_array(*d_grid->get_array(),
00289                 get_latitude_index_bottom() - get_latitude_index_top() + 1,
00290                 get_longitude_index_right() - get_longitude_index_left() + 1);
00291     }
00292 
00293     set_array_using_double(d_latitude, get_lat() + get_latitude_index_top(),
00294                            get_latitude_index_bottom() - get_latitude_index_top() + 1);
00295 
00296     set_array_using_double(d_longitude, get_lon() + get_longitude_index_left(),
00297                            get_longitude_index_right() - get_longitude_index_left() + 1);
00298 
00299     // Look for any non-lat/lon maps and make sure they are read correctly
00300     Grid::Map_iter i = d_grid->map_begin();
00301     Grid::Map_iter end = d_grid->map_end();
00302     while (i != end) {
00303         if (*i != d_latitude && *i != d_longitude) {
00304             if ((*i)->send_p()) {
00305                 DBG(cerr << "reading grid map: " << (*i)->name() << endl);
00306                 //(*i)->set_read_p(false);
00307                 (*i)->read();
00308             }
00309         }
00310         ++i;
00311     }
00312 
00313     // ... and then the Grid's array if it has been read.
00314     if (get_array_data()) {
00315         int size = d_grid->get_array()->val2buf(get_array_data());
00316 
00317         if (size != get_array_data_size())
00318             throw InternalErr(__FILE__, __LINE__, "Expected data size not copied to the Grid's buffer.");
00319 
00320         d_grid->set_read_p(true);
00321     }
00322     else {
00323         d_grid->get_array()->read();
00324     }
00325 }
00326 
00327 } // namespace libdap

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