没学过MATLAB谁能帮我改成vb
function srtmfil(file_name1,file_name2,num,method)
% SRTM data processing..............................................
% Function: srtmfil V1.0
% Fills the blank hole of SRTM3 data set
% Use Matlab 'griddata' function
% Usage:
% srtmfil(input_file_name,output_file_name,size_of_srtm_matrix,interpolation_method)
% size_of_srtm_matrix: 1201 for SRTM3, 3601 for SRTM1
% interpolation_method: Switch from 1-4
% 1= 'linear' - Triangle-based linear interpolation (default).
% 2= 'cubic' - Triangle-based cubic interpolation.
% 3= 'nearest' - Nearest neighbor interpolation.
%
% Programed by:
% Frank Chen @ www.LVYE.ORG
% History:
% V1.0 : 11-Jan-2004 on Matlab 6.1.0, by Frank chen
%
% Read the SRTM data into memory...
display('Read SRTM data ....')
fid=fopen(file_name1,'r','s');
[Z0,n]=fread(fid,[num,num],'int16');
fclose(fid);
% Process data set band by band to solve memory limitation problem...
% band width=100 ; step = 50 for SRTM3 data
b_width=100;b_step=50;
for band=1:b_step:num-b_width
display(band)
% Cut a band for processing...
Zi=Z0(band:band+b_width, 1:num);
size(Zi);
%% meshgrid
[Xi,Yi]=meshgrid(1:num,band:band+b_width);
size(Xi);
%display('srtm data sorting....')
a=[Xi(:) Yi(:) Zi(:)];
b=sortrows(a,3);
[m,n]=size(b);
%display('srtm data sorting finished....')
for i=1:m
if(b(i,3) > -2000)
j=i;
break;
end
end
% b1=b(1:j-1,:);
% b1=sortrows(b1,[1 2]);
% size(b1)
b2=b(j:m,:);
b2=sortrows(b2,[1 2]);
size(b2);
% SRTM data griding ....
x=b2(:,1); y=b2(:,2); z=b2(:,3);
switch method
case 1,
Zi=griddata(x,y,z,Xi,Yi, 'linear');
case 2,
Zi=griddata(x,y,z,Xi,Yi, 'cubic');
case 3,
Zi=griddata(x,y,z,Xi,Yi, 'nearest');
otherwise,
Zi=griddata(x,y,z,Xi,Yi, 'linear');
end
size(Zi);
% merge the bands .....
if band ==1 Z = Zi(1:b_width-(b_step/2)-1,: );
elseif band==num-b_width Z=[Z ; Zi((b_step/2):b_width+1, :)];
else Z=[Z ; Zi((b_step/2):b_width-(b_step/2)-1,:)];
end
size(Z)
% loop control of bands...
end
% SRTM data saving ....
fid=fopen(file_name2,'w','s')
fwrite(fid,Z,'int16');
fclose(fid);
