/[MITgcm]/MITgcm/pkg/mnc/README.txt
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revision 1.5 by edhill, Thu Jan 8 07:24:47 2004 UTC revision 1.12 by edhill, Fri Mar 19 03:28:36 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(       fname, myThid )
40    MNC_FILE_OPEN(         myThid, fname, itype )    MNC_FILE_OPEN(         fname, itype, myThid )
41    MNC_FILE_ADD_ATTR_STR( myThid, fname, atname, sval )    MNC_FILE_ADD_ATTR_STR( fname, atname, sval, myThid )
42    MNC_FILE_ADD_ATTR_DBL( myThid, fname, atname, len, dval )    MNC_FILE_ADD_ATTR_DBL( fname, atname, len, dval, myThid )
43    MNC_FILE_ADD_ATTR_REAL(myThid, fname, atname, len, rval )    MNC_FILE_ADD_ATTR_REAL(fname, atname, len, rval, myThid )
44    MNC_FILE_ADD_ATTR_INT( myThid, fname, atname, len, ival )    MNC_FILE_ADD_ATTR_INT( fname, atname, len, ival, myThid )
45    MNC_FILE_ADD_ATTR_ANY( myThid, fname, atname, atype, cs,len,dv,rv,iv )    MNC_FILE_ADD_ATTR_ANY( fname, atname, atype, cs,len,dv,rv,iv, myThid )
46    ...    ...
47    MNC_FILE_READ_HEADER(  myThid, fname )    MNC_FILE_READ_HEADER(  fname, myThid )
48    
49    MNC_DIM_INIT(          myThid, dname, dunits, dlen )    MNC_DIM_INIT(          fname, dname, dlen, myThid )
   MNC_DIM_REMOVE(        myThid, dname )  
50    
51    MNC_GRID_INIT(         myThid, fname, gname, ndim, dnames )    MNC_GRID_INIT(         fname, gname, ndim, dnames, myThid )
   MNC_GRID_SET_LL(       myThid, fname, gname, type, lats, lons )  
52    
53    MNC_VAR_INIT_DBL(      myThid, fname, gname, vname, units )    MNC_VAR_INIT_DBL(      fname, gname, vname, units, myThid )
54    MNC_VAR_INIT_REAL(     myThid, fname, gname, vname, units )    MNC_VAR_INIT_REAL(     fname, gname, vname, units, myThid )
55    MNC_VAR_INIT_INT(      myThid, fname, gname, vname, units )    MNC_VAR_INIT_INT(      fname, gname, vname, units, myThid )
56    MNC_VAR_INIT_ANY(      myThid, fname, gname, vname, units, type )    MNC_VAR_INIT_ANY(      fname, gname, vname, units, type, myThid )
57    MNC_VAR_ADD_ATTR_STR(  myThid, fname, vname, atname, nv, sval )    MNC_VAR_ADD_ATTR_STR(  fname, vname, atname, sval, myThid )
58    MNC_VAR_ADD_ATTR_DBL(  myThid, fname, vname, atname, nv, dval )    MNC_VAR_ADD_ATTR_DBL(  fname, vname, atname, nv, dval, myThid )
59    MNC_VAR_ADD_ATTR_REAL( myThid, fname, vname, atname, nv, rval )    MNC_VAR_ADD_ATTR_REAL( fname, vname, atname, nv, rval, myThid )
60    MNC_VAR_ADD_ATTR_INT(  myThid, fname, vname, atname, nv, ival )    MNC_VAR_ADD_ATTR_INT(  fname, vname, atname, nv, ival, myThid )
61    MNC_VAR_ADD_ATTR_ANY(  myThid, fname, vname, atname, atype, cs,len,dv,rv,iv )    MNC_VAR_ADD_ATTR_ANY(  fname, vname, atname, atype, cs,len,dv,rv,iv, myThid )
62    MNC_VAR_WRITE_DBL(     myThid, fname, vname, var )    MNC_VAR_WRITE_DBL(     fname, vname, var, myThid )
63    MNC_VAR_WRITE_REAL(    myThid, fname, vname, var )    MNC_VAR_WRITE_REAL(    fname, vname, var, myThid )
64    MNC_VAR_WRITE_INT(     myThid, fname, vname, var )    MNC_VAR_WRITE_INT(     fname, vname, var, myThid )
65    MNC_VAR_WRITE_ANY(     myThid, fname, vname, vtype, dv, rv, iv )    MNC_VAR_WRITE_ANY(     fname, vname, vtype, dv, rv, iv, myThid )
66    ...    ...
67    MNC_VAR_READ(          myThid, fname, vname, var )    MNC_VAR_READ(          fname, vname, var, myThid )
68    
69    MNC_FILE_CLOSE(        myThid, fname )    MNC_FILE_SYNC(         fname, myThid )
70      MNC_FILE_CLOSE(        fname, myThid )
71    
72  The above interface is powerful yet easy to use (easier than the  
73  entire NetCDF interface) since it helps the user keep track of the  Heres a further "convenience wrapper" written on top of the above UI:
74  associations between files, "grids", variables, and dimensions.  
75      MNC_CW_INIT(  Gtype, Htype, Hsub, Vtype, Ttype, wHalo, myThid )
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( myIter, filebn,bi,bj, Gtype, RX, vname, var, myThid )
84      MNC_CW_READ(  myIter, filebn,bi,bj, Gtype, RX, vname, var, myThid )
85    
86      MNC_CW_RX_W_YY( fbname,bi,bj, vtype, indu, var, myThid )
87      MNC_CW_RX_R_YY( fbname,bi,bj, vtype, indu, var, myThid )
88    
89      MNC_COMP_VTYPE_VAR( ind_vt, ind_fv_ids, ires, myThid )
90    
91    
92  To-Do:  To-Do:
93  ======  ======
94    
95   1) CNH pointed out that grid interpolation needs to be handled   1) NAMING -- We should (as much as possible) try to name variables so
96        that they are in agreement with the CF naming conventions.
97    
98     2) UNITS -- as with the names we need to follow conventions
99    
100     3) AM described her "diags" (or "myDiags" or "mDiags") interface
101        which should use MNC for output.  The data storage idea is similar
102        to the MNC tables-of-indicies approach but also includes one huge
103        double-precision "accumulator" to hold all the temporary values
104        (eg. partial sums for averages, current max/mins):
105    
106          vname ( ni )
107          vlen  ( ni )
108          vind  ( ni ) ------+
109                             |
110    
111          vij_diag ( i, j, [...] )  w/ lat/lon indicies
112          vgl_diag ( [...] )        wo/ lat/lon indicies (global)
113    
114     4) CNH pointed out that grid interpolation needs to be handled
115      "on-the-fly" since pre-processing would result in overly large      "on-the-fly" since pre-processing would result in overly large
116      input files.  We need an interpolation API...      input files.  We need an interpolation API...
117    
118     5) From the group meeting on 2004/01/21, we need to define
119        "sub-grids" corresponding to:
120    
121             var_name       HGRID       VGRID       TIME
122             ===========================================
123             u              U_xy        r_c         t
124             eta            T_xy        -           t
125             rac            T_xy        -           -
126    
127        And write a convenience wrapper so that users can write variables
128        using just two function calls.  JMC and I worked out the
129        following:
130    
131    
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