/[MITgcm]/MITgcm/pkg/mnc/README.txt
ViewVC logotype

Diff of /MITgcm/pkg/mnc/README.txt

Parent Directory Parent Directory | Revision Log Revision Log | View Revision Graph Revision Graph | View Patch Patch

revision 1.2 by edhill, Tue Jan 6 23:19:27 2004 UTC revision 1.9 by edhill, Tue Jan 27 05:47:32 2004 UTC
# Line 8  subroutines: Line 8  subroutines:
8    
9    1) "stubs" of the form:  MNC_WV_[G|L]2D_R[S|L] ()    1) "stubs" of the form:  MNC_WV_[G|L]2D_R[S|L] ()
10    
11    2) MNC_INIT_VGRID( 'V_GRID_TYPE', nx, ny, nz, zc, zg )    2) MNC_INIT_VGRID('V_GRID_TYPE', nx, ny, nz, zc, zg)
                                     1   1  
12    
13    3) MNC_INIT_HGRID( 'H_GRID_TYPE', nx, ny, xc, yc, xg, yg )    3) MNC_INIT_HGRID('H_GRID_TYPE', nx, ny, xc, yc, xg, yg)
14    
15    4) MNC_INIT_VAR( 'file', 'Vname', 'Vunits', 'H_GTYPE', 'V_GTYPE', PREC, FillVal )    4) MNC_INIT_VAR('file', 'Vname', 'Vunits', 'H_GTYPE', 'V_GTYPE', PREC, FillVal)
16    
17    5) MNC_WRITE_VAR( 'file', 'Vname', var, bi, bj, myThid )    5) MNC_WRITE_VAR('file', 'Vname', var, bi, bj, myThid)
18    
19  This is a reasonable start but its inflexible since it isn't easily  This is a reasonable start but its inflexible since it isn't easily
20  generalized to grids with dimensions other than [2,3,4] or grids with  generalized to grids with dimensions other than [2,3,4] or grids with
# Line 35  all the relevant information: Line 34  all the relevant information:
34  which can then be manipulated (created, associated, destroyed, etc.)  which can then be manipulated (created, associated, destroyed, etc.)
35  using a simple interface such as:  using a simple interface such as:
36    
37    MNC_INIT(              myThid )    MNC_INIT(              myThid )
38    
39    MNC_FILE_CREATE(       myThid, fname )    MNC_FILE_CREATE(       myThid, fname )
40    MNC_FILE_OPEN(         myThid, fname, itype )    MNC_FILE_OPEN(         myThid, fname, itype )
41    MNC_FILE_ADD_ATTR_STR( myThid, fname, atname, sval )    MNC_FILE_ADD_ATTR_STR( myThid, fname, atname, sval )
42    MNC_FILE_ADD_ATTR_INT( myThid, fname, atname, ival )    MNC_FILE_ADD_ATTR_DBL( myThid, fname, atname, len, dval )
43    MNC_FILE_ADD_ATTR_DBL( myThid, fname, atname, dval )    MNC_FILE_ADD_ATTR_REAL(myThid, fname, atname, len, rval )
44      MNC_FILE_ADD_ATTR_INT( myThid, fname, atname, len, ival )
45      MNC_FILE_ADD_ATTR_ANY( myThid, fname, atname, atype, cs,len,dv,rv,iv )
46    ...    ...
47    MNC_FILE_READ_HEADER(  myThid, fname )    MNC_FILE_READ_HEADER(  myThid, fname )
48    
49    MNC_DIM_INIT(          myThid, dname, dunits, dlen )    MNC_DIM_INIT(          myThid, fname, dname, dlen )
   MNC_DIM_REMOVE(        myThid, dname )  
50    
51    MNC_GRID_INIT(         myThid, fname, gname, ndim, dnames )    MNC_GRID_INIT(         myThid, fname, gname, ndim, dnames )
   MNC_GRID_SET_LL(       myThid, fname, gname, type, lats, lons )  
52    
53    MNC_VAR_INIT_DBL(      myThid, fname, gname, vname, fillval )    MNC_VAR_INIT_DBL(      myThid, fname, gname, vname, units )
54    MNC_VAR_INIT_REAL(     myThid, fname, gname, vname, fillval )    MNC_VAR_INIT_REAL(     myThid, fname, gname, vname, units )
55    MNC_VAR_INIT_INT(      myThid, fname, gname, vname, fillval )    MNC_VAR_INIT_INT(      myThid, fname, gname, vname, units )
56    MNC_VAR_ADD_ATTR_STR(  myThid, vname, name, sval )    MNC_VAR_INIT_ANY(      myThid, fname, gname, vname, units, type )
57    MNC_VAR_ADD_ATTR_INT(  myThid, vname, name, ival )    MNC_VAR_ADD_ATTR_STR(  myThid, fname, vname, atname, sval )
58    MNC_VAR_ADD_ATTR_DBL(  myThid, vname, name, dval )    MNC_VAR_ADD_ATTR_DBL(  myThid, fname, vname, atname, nv, dval )
59    MNC_VAR_WRITE(         myThid, vname, var )    MNC_VAR_ADD_ATTR_REAL( myThid, fname, vname, atname, nv, rval )
60      MNC_VAR_ADD_ATTR_INT(  myThid, fname, vname, atname, nv, ival )
61      MNC_VAR_ADD_ATTR_ANY(  myThid, fname, vname, atname, atype, cs,len,dv,rv,iv )
62      MNC_VAR_WRITE_DBL(     myThid, fname, vname, var )
63      MNC_VAR_WRITE_REAL(    myThid, fname, vname, var )
64      MNC_VAR_WRITE_INT(     myThid, fname, vname, var )
65      MNC_VAR_WRITE_ANY(     myThid, fname, vname, vtype, dv, rv, iv )
66    ...    ...
67    MNC_VAR_READ(          myThid, vname, var )    MNC_VAR_READ(          myThid, fname, vname, var )
68    
69    MNC_FILE_CLOSE(        myThid, fname )    MNC_FILE_SYNC(         myThid, fname )
70      MNC_FILE_CLOSE(        myThid, fname )
71    
72    
73    Heres a further "convenience wrapper" written on top of the above UI:
74    
75      MNC_CW_INIT(  myThid, Gtype, Htype, Hsub, Vtype, Ttype, wHalo )
76    
77        with pre-defined           -      xy    -      -      n
78        combinations:              U      x     c      t      y
79        'Cen_xy_c_t_Hn'            V      y     i
80        'U_xy_i_t_Hn',             Cen
81        'Cor_x_-_-_Hy'             Cor
82    
83      MNC_CW_WRITE( myThid,myIter, filebn,bi,bj, Gtype, RX, vname, var )
84      MNC_CW_READ(  myThid,myIter, filebn,bi,bj, Gtype, RX, vname, var )
85    
 The above interface is powerful yet easy to use (easier than the  
 entire NetCDF interface) since it helps the user keep track of the  
 associations between files, "grids", variables, and dimensions.  
86    
87    
88  To-Do:  To-Do:
89  ======  ======
90    
91   1) CNH pointed out that grid interpolation needs to be handled   1) NAMING -- We should (as much as possible) try to name variables so
92        that they are in agreement with the CF naming conventions.
93    
94     2) UNITS -- as with the names we need to follow conventions
95    
96     3) AM described her "diags" (or "myDiags" or "mDiags") interface
97        which should use MNC for output.  The data storage idea is similar
98        to the MNC tables-of-indicies approach but also includes one huge
99        double-precision "accumulator" to hold all the temporary values
100        (eg. partial sums for averages, current max/mins):
101    
102          vname ( ni )
103          vlen  ( ni )
104          vind  ( ni ) ------+
105                             |
106    
107          vij_diag ( i, j, [...] )  w/ lat/lon indicies
108          vgl_diag ( [...] )        wo/ lat/lon indicies (global)
109    
110     4) CNH pointed out that grid interpolation needs to be handled
111      "on-the-fly" since pre-processing would result in overly large      "on-the-fly" since pre-processing would result in overly large
112      input files.  We need an interpolation API...      input files.  We need an interpolation API...
113    
114     5) From the group meeting on 2004/01/21, we need to define
115        "sub-grids" corresponding to:
116    
117             var_name       HGRID       VGRID       TIME
118             ===========================================
119             u              U_xy        r_c         t
120             eta            T_xy        -           t
121             rac            T_xy        -           -
122    
123        And write a convenience wrapper so that users can write variables
124        using just two function calls.  JMC and I worked out the
125        following:
126    
127    
Legend:
Removed from v.1.2  
changed lines
  Added in v.1.9
  ViewVC Help
Powered by ViewVC 1.1.22