print out nlocs

utils/CMakeLists.txt

@@ -6,3 +6,4 @@ find_package(atlas REQUIRED)
 find_package(soca REQUIRED)
 
 add_subdirectory(soca)
+add_subdirectory(ioda_example)

utils/ioda_example/CMakeLists.txt

@@ -0,0 +1,6 @@
+ecbuild_add_executable( TARGET gdas_dumpioda.x
+                        SOURCES gdas_dumpioda.cc )
+
+target_compile_features( gdas_dumpioda.x PUBLIC cxx_std_17)
+target_link_libraries( gdas_dumpioda.x PUBLIC oops ioda)
+

utils/ioda_example/gdas_dumpioda.cc

@@ -0,0 +1,12 @@
+#include "gdas_dumpioda.h"
+#include "oops/runs/Run.h"
+
+// this is an example application that
+// will use IODA to read a file and print something
+// it is intended to be very bare bones
+
+int main(int argc, char ** argv) {
+  oops::Run run(argc, argv);
+  gdasapp::IodaExample iodaexample;
+  return run.execute(iodaexample);
+}

utils/ioda_example/gdas_dumpioda.h

@@ -0,0 +1,48 @@
+#include <iostream>
+#include "eckit/config/LocalConfiguration.h"
+#include "ioda/Group.h"
+#include "ioda/ObsSpace.h"
+#include "ioda/ObsVector.h"
+#include "oops/base/PostProcessor.h"
+#include "oops/mpi/mpi.h"
+#include "oops/runs/Application.h"
+#include "oops/util/DateTime.h"
+#include "oops/util/Duration.h"
+#include "oops/util/Logger.h"
+
+namespace gdasapp {
+
+  class IodaExample : public oops::Application {
+   public:
+    explicit IodaExample(const eckit::mpi::Comm & comm = oops::mpi::world())
+      : Application(comm) {}
+    static const std::string classname() {return "gdasapp::IodaExample";}
+
+    int execute(const eckit::Configuration & fullConfig, bool /*validate*/) const {
+
+      // get the obs space configuration
+      const eckit::LocalConfiguration obsConfig(fullConfig, "obs space");
+      ioda::ObsTopLevelParameters obsparams;
+      obsparams.validateAndDeserialize(obsConfig);
+      oops::Log::info() << "obs space: " << std::endl << obsConfig << std::endl;
+
+      // read the obs space
+      std::string winbegin;
+      std::string winend;
+      fullConfig.get("window begin", winbegin);
+      fullConfig.get("window end", winend);
+      ioda::ObsSpace ospace(obsparams, oops::mpi::world(), util::DateTime(winbegin), util::DateTime(winend), oops::mpi::myself());
+      const size_t nlocs = ospace.nlocs();
+      oops::Log::info() << "nlocs =" << nlocs << std::endl;
+
+      return 0;
+    }
+    // -----------------------------------------------------------------------------
+   private:
+    std::string appname() const {
+      return "gdasapp::IodaExample";
+    }
+    // -----------------------------------------------------------------------------
+  };
+
+}  // namespace gdasapp