/*

BDS_unpack_mex5.c
GRiB?Binary?Data?Section?decoding
Relevant?code?from?W.?Ebisuzaki?NCEP

30?Aug?2005
???fixed?alloc?sizeof?bug?noted?by?several?users?under?MATLAB7/R14
???Both?Felipe?Nievinski?and?Julien?Choisnard?noticed?that?seg?viols
???occured?because?of?the?sizeof（mxREAL）.??These?have?been?changed?to
???size（float）.??


*/

#include?
#include?
#include?“mex.h“

/*?PROTOTYPES?*/
void?BDS_unpack（float?*flt?unsigned?char?*bits?unsigned?char?*bitmap
????????int?n_bits?int?n?double?ref?double?scale）;

/************************************************************

??####?????##?????#####??######??#????#????##?????#???#
?#????#???#??#??????#????#???????#????#???#??#?????#?#
?#???????#????#?????#????#####???#????#??#????#?????#
?#??###??######?????#????#???????#?##?#??######?????#
?#????#??#????#?????#????#???????##??##??#????#?????#
??####???#????#?????#????######??#????#??#????#?????#

************************************************************/

void?mexFunction（int????????????nlhs
?????????????????mxArray??????*plhs[]
?????????????????int????????????nrhs
?????????????????const?mxArray?*prhs[]）
{
???unsigned?char?*databits?*bitmap;

???int?n_bitsnimbnb;
???double?refscaleNaN=mxGetNaN（）*tempd;
???FILE?*tempfile*fopen（）;
???float?*tempf;
???
???bool?bms_empty;
???
???databits=（unsigned?char?*）mxGetData（prhs[0]）;
???bms_empty=mxIsEmpty（prhs[1]）;

???if（bms_empty）
??????bitmap=NULL;
???else
??????bitmap=（unsigned?char?*）mxGetData（prhs[1]）;
???
???n_bits=mxGetScalar（prhs[2]）;
???n=mxGetScalar（prhs[3]）;
???ref=mxGetScalar（prhs[4]）;
???scale=mxGetScalar（prhs[5]）;
???
???/*?tempf=（float?*）mxMalloc（sizeof（mxREAL）*n）;?*/
???/*?sizeof（mxREAL）?caused?seg?viol?in?R14?*/
???tempf=（float?*）mxMalloc（sizeof（float）*n）;

???mb=mxGetM（prhs[0]）;
???nb=mxGetN（prhs[0]）;

???BDS_unpack（tempf?databits?bitmap?n_bits?n?ref?scale）;
???
???plhs[0]=mxCreateDoubleMatrix（n1mxREAL）;
???tempd=mxGetPr（plhs[0]）;
???for?（i=0;i???mxSetPr（plhs[0]tempd）;
???
???return;
}

/*?for?simple?unpacking?of?a?grid?*/
/*?wesley?ebisuzaki?NCEP?wgrib?*/
/*?http://wesley.wwb.noaa.gov?*/

/*?undefined?value?--?if?bitmap?*/
#define?UNDEFINED		9.999e20

void?BDS_unpack（float?*flt?unsigned?char?*bits?unsigned?char?*bitmap
	int?n_bits?int?n?double?ref?double?scale）?{

????int?i?j?k;
????unsigned?int?map_mask?bit_mask;

????map_mask?=?bit_mask?=?128;

????for?（i?=?0;?i?	if?（bitmap）?{
	????j?=?（*bitmap?&?map_mask）;
	????if?（（map_mask?>>=?1）?==?0）?{
		map_mask?=?128;
		bitmap++;
	????}
	????if?（j?==?0）?{
		*flt++?=?UNDEFINED;
		continue;
	????}
	}

	j?=?0;
	k?=?n_bits;
	while?（k）?{
	????if?（k?>=?8?&&?bit_mask?==?128）?{
		j?=?256?*?j?+?*bits;
		bits++;
		k?-=?8;
	????}
	????else?{
	????????j?=?j?+?j?+?（（*bits?&?bit_mask）?!=?0）;
		if?（（bit_mask?>>=?1）?==?0）?{
		????bits++;
		????bit_mask?=?128;
		}
		k--;
	????}
	}
	*flt++?=?ref?+?scale*j;
???}
???return;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件??????12292??2004-10-24?20:04??read_grib\read_grib1.4.0\.DS_Store

?????文件???????2953??2005-09-01?02:02??read_grib\read_grib1.4.0\BDS_unpack_mex5.c

?????文件???????3643??2005-09-01?01:12??read_grib\read_grib1.4.0\BDS_unpack_mex5.cv

?????文件???????6656??2007-10-15?11:16??read_grib\read_grib1.4.0\BDS_unpack_mex5.dll

?????文件???????6578??2005-09-22?04:57??read_grib\read_grib1.4.0\BDS_unpack_mex5.mexglx

?????文件???????9720??2005-09-01?01:13??read_grib\read_grib1.4.0\BDS_unpack_mex5.mexmac

?????文件???????7119??2005-08-31?22:25??read_grib\read_grib1.4.0\ECMWF128.tab

?????文件???????4203??2005-08-31?22:25??read_grib\read_grib1.4.0\ECMWF160.tab

?????文件???????9850??2005-08-31?22:24??read_grib\read_grib1.4.0\NCEPOPER.tab

?????文件??????10083??2005-08-31?22:24??read_grib\read_grib1.4.0\NCEPREAN.tab

?????文件????????221??2005-09-01?09:33??read_grib\read_grib1.4.0\private\bitshift2.m

?????文件????????237??2005-09-01?09:33??read_grib\read_grib1.4.0\private\bitshift3.m

?????文件???????1708??2005-09-01?10:05??read_grib\read_grib1.4.0\private\extract_grib.m

?????文件????????818??2005-09-01?10:10??read_grib\read_grib1.4.0\private\find_grib_marker.m

?????文件????????453??2005-09-01?10:06??read_grib\read_grib1.4.0\private\get_bds.m

?????文件????????374??2005-09-01?10:07??read_grib\read_grib1.4.0\private\get_bms.m

?????文件???????2089??2005-09-01?10:06??read_grib\read_grib1.4.0\private\get_gds.m

?????文件????????272??2005-09-01?10:18??read_grib\read_grib1.4.0\private\Get_Parameter.m

?????文件???????1892??2005-09-01?10:08??read_grib\read_grib1.4.0\private\get_pds.m

?????文件???????4974??2005-09-01?10:18??read_grib\read_grib1.4.0\private\gribhelp.m

?????文件???????1201??2005-09-01?09:30??read_grib\read_grib1.4.0\private\ibm2flt.m

?????文件????????439??2005-09-01?09:33??read_grib\read_grib1.4.0\private\int2.m

?????文件???????1765??2005-09-01?09:32??read_grib\read_grib1.4.0\private\int3.m

?????文件????????457??2005-09-01?10:19??read_grib\read_grib1.4.0\private\is_grib_file.m

?????文件???????1858??2005-09-01?10:18??read_grib\read_grib1.4.0\private\levels.m

?????文件??????53215??2005-09-01?10:09??read_grib\read_grib1.4.0\private\Set_Parameter_Table.m

?????文件???????1248??2005-09-01?10:14??read_grib\read_grib1.4.0\private\table0.m

?????文件????????353??2005-09-01?10:15??read_grib\read_grib1.4.0\private\table1.m

?????文件???????3181??2005-09-01?10:16??read_grib\read_grib1.4.0\private\table3a.m

?????文件????????299??2005-09-01?10:16??read_grib\read_grib1.4.0\private\table4.m

............此處省略19個文件信息