From dcbc249fd70e4f2d519c9571c2f6f5c27f32ef97 Mon Sep 17 00:00:00 2001
From: Michael Uleysky <uleysky@poi.dvo.ru>
Date: Fri, 1 Sep 2023 15:12:37 +1000
Subject: [PATCH] Netcdf output files made more COARDS-compliant

---
 actions/actionuv.cpp |  7 +++++++
 include/ncfilew.h    | 18 +++++++++---------
 src/ncfilew.cpp      | 12 ++++++++++++
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/actions/actionuv.cpp b/actions/actionuv.cpp
index 434d72c..69ba2c0 100644
--- a/actions/actionuv.cpp
+++ b/actions/actionuv.cpp
@@ -49,6 +49,13 @@ MString UVMethods::StPoints::WriteNcFile(const MString& name, const MString& his
   text = "latitude";
   ret  = nc_put_att_text(ncid, yid, "standard_name", text.Len() + 1, text.Buf());
   if(ret != NC_NOERR) return "Can't write standard_name attribute of latitude variable in the netcdf file";
+
+  text = "Longitude";
+  ret  = nc_put_att_text(ncid, xid, "long_name", text.Len() + 1, text.Buf());
+  if(ret != NC_NOERR) return "Can't write long_name attribute of longitude variable in the netcdf file";
+  text = "Latitude";
+  ret  = nc_put_att_text(ncid, yid, "long_name", text.Len() + 1, text.Buf());
+  if(ret != NC_NOERR) return "Can't write long_name attribute of latitude variable in the netcdf file";
  }
 
  ret = nc_def_var_deflate(ncid, xid, 1, 1, comp);
diff --git a/include/ncfilew.h b/include/ncfilew.h
index fdce58c..1cfb1a6 100644
--- a/include/ncfilew.h
+++ b/include/ncfilew.h
@@ -31,7 +31,7 @@ class NCFileW
  {
   struct
   {
-   int xdimid, ydimid;
+   int ydimid, xdimid;
   };
   int dimid[2];
  };
@@ -114,11 +114,11 @@ class NCFileW
   else
   {
    const size_t i[2] = {0, 0};
-   const size_t c[2] = {data.Nx(), data.Ny()};
+   const size_t c[2] = {data.Ny(), data.Nx()};
    float        buf[c[0] * c[1]];
 
-   for(size_t ix = 0; ix < c[0]; ix++)
-    for(size_t iy = 0; iy < c[1]; iy++) buf[ix * c[1] + iy] = data.IsFill(ix, iy) ? fill : op(ix, iy);
+   for(size_t iy = 0; iy < c[0]; iy++)
+    for(size_t ix = 0; ix < c[1]; ix++) buf[iy * c[1] + ix] = data.IsFill(ix, iy) ? fill : op(ix, iy);
 
    ret = nc_put_vara_float(ncid, vars[v].id, i, c, buf);
    if(ret != NC_NOERR) return "Can't write " + vars[v].name + " variable in the netcdf file";
@@ -179,14 +179,14 @@ class NCFileW
   else if constexpr(dtype == G2V2)
   {
    const size_t i[2] = {0, 0};
-   const size_t c[2] = {data.Nx(), data.Ny()};
+   const size_t c[2] = {data.Ny(), data.Nx()};
    float        bufx[c[0] * c[1]];
    float        bufy[c[0] * c[1]];
-   for(size_t ix = 0; ix < c[0]; ix++)
-    for(size_t iy = 0; iy < c[1]; iy++)
+   for(size_t iy = 0; iy < c[0]; iy++)
+    for(size_t ix = 0; ix < c[1]; ix++)
     {
-     bufx[ix * c[1] + iy] = data.Lon(ix, iy);
-     bufy[ix * c[1] + iy] = data.Lat(ix, iy);
+     bufx[iy * c[1] + ix] = data.Lon(ix, iy);
+     bufy[iy * c[1] + ix] = data.Lat(ix, iy);
     }
    ret = nc_put_vara_float(ncid, xid, i, c, bufx);
    if(ret != NC_NOERR) return "Can't write longitude variable in the netcdf file";
diff --git a/src/ncfilew.cpp b/src/ncfilew.cpp
index a4f0f35..a5938e4 100644
--- a/src/ncfilew.cpp
+++ b/src/ncfilew.cpp
@@ -10,12 +10,17 @@ MString NCFileW::CreateFile(NCFileW::Type stype, const MString& name, const MStr
  int     ret;
  MString text;
 
+ const float node_offset = 0.0;
+
  ret = nc_create(name.Buf(), NC_CLOBBER | NC_NETCDF4, &ncid);
  if(ret != NC_NOERR) return "Can't create netcdf file: " + name;
 
  ret = nc_put_att_text(ncid, NC_GLOBAL, "history", history.Len() + 1, history.Buf());
  if(ret != NC_NOERR) return "Can't write history attribute in the netcdf file";
 
+ ret = nc_put_att(ncid, NC_GLOBAL, "node_offset", NC_FLOAT, 1, &node_offset);
+ if(ret != NC_NOERR) return "Can't write history attribute in the netcdf file";
+
  switch(stype)
  {
  case(G1V1):
@@ -67,6 +72,13 @@ MString NCFileW::CreateFile(NCFileW::Type stype, const MString& name, const MStr
  ret  = nc_put_att_text(ncid, yid, "standard_name", text.Len() + 1, text.Buf());
  if(ret != NC_NOERR) return "Can't write standard_name attribute of latitude variable in the netcdf file";
 
+ text = "Longitude";
+ ret  = nc_put_att_text(ncid, xid, "long_name", text.Len() + 1, text.Buf());
+ if(ret != NC_NOERR) return "Can't write long_name attribute of longitude variable in the netcdf file";
+ text = "Latitude";
+ ret  = nc_put_att_text(ncid, yid, "long_name", text.Len() + 1, text.Buf());
+ if(ret != NC_NOERR) return "Can't write long_name attribute of latitude variable in the netcdf file";
+
  type = stype;
  return "";
 }