1$Id: README,v 1.8 1999/07/21 16:37:36 steve Exp $ 2 3Greetings, 4 5 This file briefly describes the netCDFPerl package. 6 7INTRODUCTION 8------------ 9 10 The netCDFPerl package is a perl extension for accessing netCDF 11 datasets based on version 2 of the netCDF package (netCDF-2). For 12 example, the following netCDF-2 actions: 13 14 1. Open dataset "foo.nc"; 15 16 2. Write a 2 x 3 array of double-precision values into the 17 starting corner of the first variable; and 18 19 3. Close the dataset. 20 21 can be accomplished by the following C fragment: 22 23 int ncid = ncopen("foo.nc", NC_WRITE); 24 int varid = 0; 25 long start[2], count[2]; 26 double values[6]; 27 28 ncid = ncopen("foo.nc", NC_WRITE); 29 30 start[0] = 0; 31 start[1] = 0; 32 count[0] = 2; 33 count[1] = 3; 34 35 values[0] = 0.0; 36 values[1] = 1.0; 37 values[2] = 2.0; 38 values[3] = 3.0; 39 values[4] = 4.0; 40 values[5] = 5.0; 41 42 ncvarput(ncid, varid, start, count, values); 43 44 ncclose(ncid); 45 46 or by this equivalent perl fragment: 47 48 use NetCDF; 49 50 $ncid = NetCDF::open("foo.nc", NetCDF::WRITE); 51 $varid = 0; 52 @start = (0, 0); 53 @count = (2, 3); 54 @values = (0, 1, 2, 3, 4, 5); 55 NetCDF::varput($ncid, $varid, \@start, \@count, \@values); 56 NetCDF::close($ncid); 57 58 There are perl-callable functions for all appropriate functions of 59 the netCDF-2 API. 60 61netCDF-2 vs. netCDF-3 62--------------------- 63 64 Currently, the NetCDFPerl extension module is implemented using 65 version 2 of the netCDF API (netCDF-2). On 1997-05-16, version 3 66 of the netCDF package was released (netCDF-3). This newer version, 67 however, contains a netCDF-2 backward compatibility interface. 68 Thus, with a few minor changes already made, NetCDFPerl works with 69 netCDF-3 as well as netCDF-2. 70 71 Users should be aware, however, that the NetCDFPerl user-interface 72 is based on netCDF-2. In particular, the NetCDFPerl documentation 73 doesn't describe the NetCDFPerl interface in detail but instead 74 describes the differences between it and the netCDF-2 interface. 75 The intention was that users would use the NetCDFPerl and netCDF-2 76 documentation together in order to program using NetCDFPerl. 77 78 With the deprecation of the netCDF-2 interface, this has become 79 slightly problematical -- but not unworkable. The solution is to 80 ensure the availability of the netCDF-2 documentation. Currently, 81 the netCDF version 2 User's Guide is available at the following URL: 82 83 ftp://ftp.unidata.ucar.edu/pub/netcdf/guide-2.4.3.ps.Z 84 85 and the netCDF-library manual page for netCDF-2 is available as the 86 file "netcdf-2.4.3/src/doc/netcdf.3" in the netCDF-2 distribution at 87 the following URL: 88 89 ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-2.4.3.tar.Z 90 91 92AVAILABILITY 93------------ 94 95 netCDFPerl is freely available from either of the following URLs: 96 97 http://www.unidata.ucar.edu/packages/netcdf-perl/ 98 99 or 100 101 ftp://ftp.unidata.ucar.edu/pub/netcdf-perl/netcdf-perl.tar.Z 102 103INSTALLATION 104------------ 105 106 See the file INSTALL in the top-level directory of the netCDFPerl 107 distribution for instructions on how to incorporate netCDFPerl into 108 your perl utility. 109 110 You will need write access to your installed perl(1) libraries in 111 order to install netCDFPerl. 112 113ADDITIONAL INFORMATION 114---------------------- 115 116 See the installed manual page, netCDFPerl(1), for additional 117 information. 118 119 There is a WWW page for netCDFPerl. It's URL is 120 121 http://www.unidata.ucar.edu/packages/netcdf-perl 122 123MAILING-LIST 124------------ 125 126 There is a netCDFPerl mailing-list. To subscribe, send to the 127 following address: 128 129 majordomo@unidata.ucar.edu 130 131 a message whose body consists solely of the following: 132 133 subscribe netcdf-perl [opt-addr] 134 135 where [opt-addr] is an optional email address -- if you use it, then 136 mailing-list postings will be sent to it; otherwise, they will be 137 sent to the return address of the subscription request. 138 139 140Regards, 141Steve Emmerson <support@unidata.ucar.edu> 142