read_las_file.m

基于Matlab的地震数据处理显示和测井数据显示于处理的小程序

      end
      wlog.first = sscanf(buffer(ia+nu:ind),'%f',1);
    end

    if strcmpi(kw,'STOP')
      if ~strcmp(buffer(ia),' ')
%      if buffer(ia) ~= ' '
        temp=sscanf(buffer(ia:ind),'%s',1);
        nu=length(temp);
      else
        nu=0;
      end
      wlog.last = sscanf(buffer(ia+nu:ind), '%f',1);
    end 

    if strcmpi(kw,'STEP')
%      if buffer(ia) ~= ' '
      if ~strcmp(buffer(ia),' ')
        nu=length(temp);
      else
        nu=0;
      end
      wlog.step = sscanf(buffer(ia+nu:ind), '%f');
      wlog.units='';	% Place holder
    end
       
    if strcmpi(kw,'NULL')
      wlog.null = sscanf(buffer(ia:ind), '%f');  
    end

    if strcmpi(kw,'COMP')
      wlog.company = strim(buffer(ia:ind));  
    end	
	      
    if strcmpi(kw,'WELL')
      wlog.wellname = strim(buffer(ia:ind));
    end

    if strcmpi(kw,'FLD')
      wlog.field = strim(buffer(ia:ind));  
    end	
	      
    if strcmpi(kw,'LOC')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.location = temp; end 
    end	

    if strcmpi(kw,'PROV')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.province = temp; end 
    end	
	      		      
    if strcmpi(kw,'CTRY')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.country = temp; end;
    end

    if strcmpi(kw,'CNTY')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.county = temp; end;
    end

    if strcmpi(kw,'STAT')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.state = temp; end;
    end

    if strcmpi(kw,'UWI')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.wellid = temp; end
    end

    if strcmpi(kw,'API')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.api = temp; end
    end

    if strcmpi(kw,'SRVC')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.service = temp; end
    end

    if strcmpi(kw,'DATE')
      temp=strim(buffer(ia:ind));
      if ~isempty(temp), wlog.date = temp; end 
    end
		      
    buffer=get_buffer(fid);
  end
  if iprint ~= 0, disp('... finished reading well info'); end
end

% 	Parameter information block
if strcmpi(buffer(1:2),'~p') 
  unknown_block=0;
  nhead=nhead+1;
  lb=min([length(buffer),nchar]);
  bmax=max([lb,bmax]);
  las_header(nhead,1:lb)=buffer(1:lb);
  
  if iprint ~= 0, disp('... reading parameter info'); end
  buffer=get_buffer(fid);	   
  while buffer(1:1) ~= '~' 
    nhead=nhead+1; 
    lb=min([length(buffer),nchar]);
    bmax=max([lb,bmax]);
    las_header(nhead,1:lb)=buffer(1:lb);

    if ~strcmpi(buffer(1),'#') 
      ind=find(buffer(1:min([lb-1,21])) == '.')-1; 
      ind=ind(1);
      parameter=lower(strim(buffer(1:ind)));
      ind1=find(buffer == ':');

      if ~strcmpi(buffer(ind+2),' ') & ~strcmpi(buffer(ind+2),':')
         unit=sscanf(buffer(ind+2:ind1-1),'%s',1);
         nu=length(unit);
         unit=char(unit_substitution(unit));%  Change abbreviations for units of measurement
      else
         unit='UNDEFINED';
         nu=0;
      end

      value=strim(buffer(ind+nu+2:ind1-1));
      temp=strim(buffer(ind1+1:end));
      if ~isempty(temp)
	     n=min([60 length(temp)]);
	     descr=temp(1:n);
      else
         descr='UNDEFINED';
      end
      if isnumber(value)
         if str2double(value) ~= wlog.null
            if ~isfield(wlog,'parameter_info')
	           wlog.parameter_info={parameter,unit,descr}; 
            else
	           wlog.parameter_info=[wlog.parameter_info;
	                           {parameter,unit,descr}];
            end
 %           wlog.parameter_info=setfield(wlog.parameter_info,parameter,{unit,descr});
            wlog=setfield(wlog,parameter,str2double(value));
 %           wlog.(parameter)=str2num(value);
         end
      end
    end

    buffer=get_buffer(fid);
  end
%   if isempty(wlog.parameter_info), wlog=rmfield(wlog,'parameter_info'); end

  if iprint ~= 0, disp('... finished reading parameter info'); end

end  

% 	Curve information block
if strcmpi(buffer(1:2),'~c') 
  unknown_block=0;
  nhead=nhead+1;
  lb=min([length(buffer),nchar]);
  bmax=max([lb,bmax]);
  las_header(nhead,1:lb)=buffer(1:lb);
  
  if iprint ~= 0, disp('... reading curve info'); end
  buffer=get_buffer(fid);

  nlogs=0;	   
  while isempty(buffer) | buffer(1:1) ~= '~'
    nhead=nhead+1; 
    lb=min([length(buffer),nchar]);
    bmax=max([lb,bmax]);
    las_header(nhead,1:lb)=buffer(1:lb);
    if  ~strcmp(buffer(1),'#')
      nlogs=nlogs+1;
      ind=find(buffer(1:min(length(buffer),mnem_length+1)) == '.')-1;
      if isempty(ind)
        disp(' No period (dot) found.')
        disp([' Curve mnemonic could be longer than ',num2str(mnem_length),' characters:'])
        disp(buffer)
        fclose(fid);
        error(' Abnormal termination')
      end

%		Get units of measurement
      ind1=find(buffer == ':');
      if ~strcmp(buffer(ind+2),' ')
%       curve_info(2,nlogs)={sscanf(buffer(ind+2:ind1-1),'%s',1)};
        temp=strim(buffer(ind+2:ind1-1));
        idx=findstr(temp,'  ');
        if ~isempty(idx)  % Are there blanks in the unit description?
          idx1=find(diff(idx)==1);
          if isempty(idx1)
             curve_info{2,nlogs}=temp;
          else
             curve_info{2,nlogs}=temp(1:idx(idx1(1))-1);
          end
        else
          curve_info{2,nlogs}=temp;
        end
      else
        curve_info{2,nlogs}='UNDEFINED';
      end

%		Get description
      ind2=find(buffer(ind1+1:end) > 64);
      if ~isempty(ind2)
        curve_info{3,nlogs}=buffer(ind1+ind2(1):end);
      else
        curve_info{3,nlogs}='UNDEFINED';
      end

      curve_info{1,nlogs}=deblank(buffer(1:ind(1)));
    end
    buffer=get_buffer(fid);
  end

  if iprint ~= 0, disp('... finished reading curve info'); end
end  

% 	Other information block
if strcmpi(buffer(1:2),'~o') 
  unknown_block=0;
  nhead=nhead+1;
  lb=min([length(buffer),nchar]);
  bmax=max([lb,bmax]);
  las_header(nhead,1:lb)=buffer(1:lb);
  if iprint ~= 0, disp('... reading other information'); end
  buffer=deblank(fgetl(fid));
  nhead=nhead+1;
  lb=min([length(buffer),nchar]);
  bmax=max([lb,bmax]);
  las_header(nhead,1:lb)=buffer(1:lb);

  while isempty(buffer) | buffer(1:1) ~= '~' 
    nhead=nhead+1;
    lb=min([length(buffer),nchar]);
    bmax=max([lb,bmax]);
    las_header(nhead,1:lb)=buffer(1:lb); 
    buffer=deblank(fgetl(fid)); 
  end

  if iprint ~= 0, disp('... finished reading other information'); end
end       

if unknown_block == 1     	% Unknown block encountered: 
				% Write it to header
  nhead=nhead+1;
  lb=min([length(buffer)-1,nchar]);
  bmax=max([lb,bmax]);
  las_header(nhead,1:lb)=buffer(1:lb); 
  buffer=deblank(fgetl(fid)); 
  while  ~isempty(buffer) & buffer(1:1) ~= '~'
    nhead=nhead+1;
    lb=min([length(buffer),nchar]);
    bmax=max([lb,bmax]);
    las_header(nhead,1:lb)=buffer(1:lb); 
    buffer=get_buffer(fid); 
  end
end                        
		end      % Last block (log curves) reached

nhead=nhead+1;
lb=min([length(buffer),nchar]);
% bmax=max([lb,bmax]);
las_header(nhead,1:lb)=buffer(1:lb);
las_header=deblank(char(las_header(1:nhead,:)));

%	ASCI log curves
% nhead=nhead+1;
% lb=min([length(buffer),nchar]);
% bmax=max([lb,bmax]);

if iprint ~= 0, disp('... reading ASCII curve values'); end
wlog.curves=fscanf(fid,'%g',[nlogs,inf])';
if iprint ~= 0, disp('... finished reading ASCII curve values'); end

fclose(fid);

wlog.curve_info=curve_info';

if strcmpi(curve_info{1,1},'dept')
   wlog.curve_info{1,1}='DEPTH';
end

%	Change abbreviations for units of measurement
for ii=1:nlogs
  wlog.curve_info(ii,2)=unit_substitution(wlog.curve_info(ii,2));
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function buffer=get_buffer(fid)
% Get next line in file
% INPUT
% fid     file identifier
% OUTPUT
% buffer  line of text

buffer=strim(fgetl(fid));
while isempty(buffer)
   buffer=strim(fgetl(fid));
end

if length(buffer == 1)
   buffer=[buffer,' '];
end