1NCFLINT(1)                  General Commands Manual                 NCFLINT(1)
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NAME

6       ncflint - netCDF File Interpolator
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SYNTAX

9       ncflint  [-3] [-4] [-5] [-6] [-7] [-A] [--bfr sz_byt][-C][-c][--cnk_byt
10       sz_byt][--cnk_csh   sz_byt][--cnk_dmn   nm,sz_lmn]   [--cnk_map    map]
11       [--cnk_min  sz_byt]  [--cnk_plc plc] [--cnk_scl sz_lmn][-D dbg_lvl] [-d
12       dim,[ min][,[ max]]] [-F] [--fl_fmt=fmt] [--fix_rec_crd]  [-G  gpe_dsc]
13       [-g  grp[,...]]   [--glb  att_name=  att_val]]  [-h] [--hdf] [--hdr_pad
14       sz_byt][--hpss_try] [-i var,val3][-L  dfl_lvl][-l  path]  [--msa]  [-N]
15       [--no_cll_msr]  [--no_frm_trm]  [--no_tmp_fl]  [-O]  [-p  path]  [--ppc
16       var1[, var2[,...]]= prc]] [-R] [-r] [--ram_all]  [-t  thr_nbr]  [--uio]
17       [--unn]  [-v  var[,...]]   [-w  wgt[,  wgt2]] [-X box] [-x] file1 file2
18       file3
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DESCRIPTION

21       ncflint creates an output file that is a linear combination of the  in‐
22       put  files.   This linear combination can be a weighted average, a nor‐
23       malized weighted average, or an interpolation of the input files.   Co‐
24       ordinate  variables  are  not  acted  upon in any case, they are simply
25       copied from file_1.
26        There are two conceptually distinct methods  of  using  ncflint.   The
27       first method is to specify the weight each input file is to have in the
28       output file.  In this method, the value val3 of a variable in the  out‐
29       put  file file_3 is determined from its values val1 and val2 in the two
30       input files according to wgt1*val1+wgt2*val2
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32       Here at least wgt1, and, optionally, wgt2, are specified on the command
33       line  with  the -w (or --weight or --wgt_var ) switch.  If only wgt1 is
34       specified then wgt2 is automatically  computed  as  wgt2=1-wgt1.   Note
35       that weights larger than 1 are allowed.  Thus it is possible to specify
36       wgt1=2 and wgt2=-3.  One can use this functionality to multiply all the
37       values in a given file by a constant.
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39       The  second method of using ncflint is to specify the interpolation op‐
40       tion with -i (or with the --ntp or --interpolate long options). This is
41       really  the  inverse  of the first method in the following sense.  When
42       the user specifies the weights directly, ncflint has no work to do  be‐
43       sides  multiplying  the  input  values  by their respective weights and
44       adding the results together to produce the output values.  This assumes
45       it  is  the weights that are known a priori.  In another class of cases
46       it is the "arrival value" (i.e., val3 ) of a  particular  variable  var
47       that  is  known a priori.  In this case, the implied weights can always
48       be inferred by examining the values of var in the  input  files.   This
49       results   in   one   equation   in   two   unknowns,   wgt1  and  wgt2:
50       val3=wgt1*val1+wgt2*val2.
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52       Unique determination of the weights requires  imposing  the  additional
53       constraint  of normalization on the weights: wgt1+wgt2=1.  Thus, to use
54       the interpolation option, the user specifies var and val3 with  the  -i
55       option.   ncflint  will compute wgt1 and wgt2, and use these weights on
56       all variables to generate the output file.  Although var may  have  any
57       number  of  dimensions  in the input files, it must represent a single,
58       scalar value.  Thus any dimensions associated with var must be  "degen‐
59       erate", i.e., of size one.
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61        If  neither  -i  nor  -w is specified on the command line, ncflint de‐
62       faults to weighting each input file equally in the output  file.   This
63       is  equivalent to specifying -w 0.5 or -w 0.5,0.5.  Attempting to spec‐
64       ify both -i and -w methods in the same command is an error.
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66       ncflint is programmed not to interpolate variables of type NC_CHAR  and
67       NC_BYTE.  This behavior is hardcoded.
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AUTHOR

71       NCO  manual pages written by Charlie Zender and originally formatted by
72       Brian Mays.
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74

REPORTING BUGS

76       Report bugs to <http://sf.net/bugs/?group_id=3331>.
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80       Copyright © 1995-2018 Charlie Zender
81       This is free software; see the source for copying conditions.  There is
82       NO  warranty;  not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
83       PURPOSE.
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SEE ALSO

87       The full documentation for NCO is maintained as a Texinfo manual called
88       the  NCO Users Guide.  Because NCO is mathematical in nature, the docu‐
89       mentation includes TeX-intensive portions not  viewable  on  character-
90       based  displays.  Hence the only complete and authoritative versions of
91       the NCO Users Guide are the PDF (recommended), DVI, and Postscript ver‐
92       sions  at <http://nco.sf.net/nco.pdf>, <http://nco.sf.net/nco.dvi>, and
93       <http://nco.sf.net/nco.ps>, respectively.  HTML and  XML  versions  are
94       available          at          <http://nco.sf.net/nco.html>         and
95       <http://nco.sf.net/nco.xml>, respectively.
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97       If the info and NCO programs are properly installed at your  site,  the
98       command
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100              info nco
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102       should  give  you access to the complete manual, except for the TeX-in‐
103       tensive portions.
104
105       ncap(1), ncap2(1), ncatted(1), ncbo(1), ncclimo(1), nces(1), ncecat(1),
106       ncflint(1),  ncks(1), nco(1), ncpdq(1), ncra(1), ncrcat(1), ncremap(1),
107       ncrename(1), ncwa(1)
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HOMEPAGE

111       The NCO homepage at <http://nco.sf.net> contains more information.
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