DM-41634: Add PixelMap subclass using AST mappings

CMakeLists.txt

@@ -16,6 +16,18 @@ add_compile_definitions(USE_YAML=TRUE)
 
 find_library(FFTW3 fftw3 REQUIRED)
 
+# find astshim library using EUPS package environent variable as hint
+find_library(ASTSHIM_LIBRARIES
+astshim REQUIRED
+HINTS $ENV{ASTSHIM_DIR}/lib
+)
+#find astshim include directory
+find_path(
+ASTSHIM_INCLUDES
+astshim.h REQUIRED
+HINTS $ENV{ASTSHIM_DIR}/include
+)
+
 # TMV or Eigen must be available, but TMV is preferred
 find_package(TMV QUIET)
 if(TMV_FOUND)

astrometry/CMakeLists.txt

@@ -1,5 +1,5 @@
 add_library(astrometry src/Astrometry.cpp src/PiecewiseMap.cpp src/PixelMapCollection.cpp src/SubMap.cpp 
             src/Wcs.cpp src/PixelMap.cpp src/PolyMap.cpp src/TemplateMap.cpp src/YAMLCollector.cpp)
 
-target_include_directories(astrometry PUBLIC ${PROJECT_SOURCE_DIR}/astrometry/include)
+target_include_directories(astrometry PUBLIC ${PROJECT_SOURCE_DIR}/astrometry/include ${ASTSHIM_INCLUDES})
 target_link_libraries(astrometry PUBLIC Eigen3::Eigen ${FFTW3_LIBRARIES} yaml-cpp gbutil)

astrometry/include/PixelMap.h

@@ -17,6 +17,8 @@
 #ifdef USE_YAML
 #include "yaml-cpp/yaml.h"
 #endif
+#include "astshim.h"
+
 #include "Std.h"
 #include "LinearAlgebra.h"
 #include "Astrometry.h"
@@ -332,5 +334,37 @@ namespace astrometry {
     void operator=(const ColorTerm& rhs) = delete;
 
   };
+
+  class ASTMap: public PixelMap {
+    // Class representing a constant shift of position
+  public:
+    ASTMap(const ast::Mapping& mapping_, string name_=""):
+      PixelMap(name_), mapping(mapping_) {}
+
+    virtual PixelMap* duplicate() const;
+
+    ~ASTMap() {}
+
+    static string type() {return "AST";}
+
+    ast::Mapping mapping;
+
+    void toWorld(double xpix, double ypix,
+                 double &xworld, double &yworld,
+                 double color=astrometry::NODATA) const;
+    void toPix(double xworld, double yworld,
+               double &xpix, double &ypix,
+               double color = astrometry::NODATA) const;
+
+#ifdef USE_YAML
+    // AST maps are not expected to be used for output, so we do not
+    // attempt to write a full description to yaml.
+    virtual void write(YAML::Emitter &os) const
+    {
+      os << YAML::BeginMap << YAML::Key << "Type" << YAML::Value << type()
+         << YAML::EndMap;
+    }
+#endif
+  };
 } // namespace astrometry
 #endif //PIXMAP_H

astrometry/src/PixelMap.cpp

@@ -350,3 +350,30 @@ ConstantMap::create(const YAML::Node& node,
   }
 }
 #endif
+
+PixelMap*
+ASTMap::duplicate() const {
+  std::shared_ptr<ast::Mapping> newMapping = mapping.copy();
+  return new ASTMap(*newMapping);
+}
+
+void 
+ASTMap::toWorld(double xpix, double ypix,
+		 double& xworld, double& yworld,
+     double color) const {
+
+  std::vector<double> pixCoords{xpix, ypix};
+  std::vector<double> worldCoord = mapping.applyForward(pixCoords);
+  xworld = worldCoord[0];
+  yworld = worldCoord[1];
+}
+
+void 
+ASTMap::toPix( double xworld, double yworld,
+		double &xpix, double &ypix,
+    double color) const {
+  std::vector<double> worldCoords(xworld, yworld);
+  std::vector<double> pixCoord = mapping.applyInverse(worldCoords);
+  xpix = pixCoord[0];
+  ypix = pixCoord[1];
+}

pydir/CMakeLists.txt

@@ -7,8 +7,8 @@ set(PYTHON_MODULE_EXTENSION ".so")
 
 pybind11_add_module(wcsfit wcsfit.cpp)
 
-target_link_libraries(wcsfit PUBLIC subs cfitsio)
+target_link_libraries(wcsfit PUBLIC subs cfitsio ${ASTSHIM_LIBRARIES})
 
-target_include_directories(wcsfit PUBLIC ${PROJECT_SOURCE_DIR}/include)
+target_include_directories(wcsfit PUBLIC ${PROJECT_SOURCE_DIR}/include ${ASTSHIM_INCLUDES})
 
 install(TARGETS wcsfit DESTINATION "${PROJECT_SOURCE_DIR}")

pydir/wcsfit.cpp

@@ -13,6 +13,7 @@
 #include "TPVMap.h"
 #include "WCSFoFRoutine.h"
 #include "WCSFitRoutine.h"
+#include "astshim.h"
 
 using namespace pybind11::literals;
 namespace py = pybind11;
@@ -102,6 +103,10 @@ PYBIND11_MODULE(wcsfit, m) {
     py::class_<astrometry::SubMap, astrometry::PixelMap>(m, "SubMap")
             .def(py::init<list<astrometry::PixelMap *> const &, std::string, bool>());
 
+    py::class_<astrometry::ASTMap, astrometry::PixelMap>(m, "ASTMap")
+            .def(py::init<ast::Mapping, std::string>(),
+                 py::arg("mapping_"), py::arg("name_") = "");
+
     py::class_<astrometry::Wcs, std::shared_ptr<astrometry::Wcs>>(m, "Wcs")
             .def(py::init<astrometry::PixelMap *, astrometry::SphericalCoords const &, std::string, double,
                           bool>(),

ups/gbdes.table

@@ -1 +1,2 @@
+setupRequired(astshim)
 envPrepend(PYTHONPATH, ${PRODUCT_DIR}/build/pydir)