l_convert.m

function wlog=l_convert(curves,info,aux_wlog)
% Function converts a matrix of curve values, curve names, curve units of measurement, 
% curve description, etc. into a well log structure.
% Written by: E. R.: Date Feb. 12, 2000;  
% Last updated: January 1, 2006: Add field "units".
%
%          wlog=l_convert(curves,info,aux_wlog)  
% INPUT
% curves   Matrix of log curves; the first column represents depth 
%          or equivalent (e. g. travel time)
% info     cell array of the form {mnemonic,units,description}; 
%          one row for each column of "curves".
%          Example: {'rho','g/cm3','Density'; 'DTp','us/ft','Sonic'}
% aux_wlog   optional log structure from which some of the fields not
%          specified with the data above can be copied
% OUTPUT
% wlog		Structure
%         wlog.type     'well_log'
%         wlog.name     'Synthetic log'
%         wlog.tag      'unspecified'
%         wlog.curve_inf    Cell array with curve mnemonics, units of
%                       measurement, and curve descriptions for each curve
%	  wlog.curves	Matrix of curve values
%         wlog.first	Start of log (first depth in file)
%         wlog.last	End of log (last depth in file)
%	  wlog.step	Depth increment (0 if unequal)
%         wlog.units    Units of measurement for depth (info{1,2})
%	  wlog.null	Null value
%         wlog.date	Date  (current date)
%
% The above fields do not represent all the fields required to create a 
% valid LAS file. In particular, the LAS standard requires the following
% pieces of information:
%        wlog.company     Company
%        wlog.well        Name of well
%        wlog.field       Field name
%        wlog.location    Location of well
% Sometimes there already exists a log structure which has this information.
% In this case the optional input parameter aux_wlog can be used to copy 
% this information to the new log structure.      

global S4M

run_presets_if_needed

% 	Check for input compatibility
[n,m]=size(curves);
if n == 0
   error('Curve array empty')
end

ninfo=size(info,1);

if ninfo ~= m
   error(['Number of curve mnemonics (',num2str(ninfo),...
    ') different from number of curves (',num2str(m),')'])
end

% 	Store input in structure
wlog.type='well_log';
wlog.name='Log created from matrix';
wlog.tag='unspecified';
wlog.curve_info=info;

if curves(1,1) > curves(end,1)
   wlog.curves=flipud(curves);
else
   wlog.curves=curves;
end

wlog.first=wlog.curves(1,1);
wlog.last=wlog.curves(end,1);
wlog.step=depths2step_with_checking(wlog.curves(:,1));
wlog.units=info{1,2};

if any(any(isnan(curves(:,2:end))))
   wlog.null=NaN;
end

wlog.date=date;
%    For internal use
   wlog.company='Generic Contractor';
   wlog.field='unknown field';
   wlog.location='unknown location';
   wlog.wellname='unknown well';
%    End of internal-use fields
     
if nargin == 5   	% Check if input arguments include a log structure
   if isstruct(aux_wlog)
      if isfield(aux_wlog,'company'), wlog.company=aux_wlog.company;   end
      if isfield(aux_wlog,'wellname'),wlog.wellname=aux_wlog.wellname; end 
      if isfield(aux_wlog,'field'),   wlog.field=aux_wlog.field;       end
      if isfield(aux_wlog,'location'),wlog.location=aux_wlog.location; end  
      if isfield(aux_wlog,'api'), 	  wlog.api=aux_wlog.api;       end
      if isfield(aux_wlog,'province'),wlog.province=aux_wlog.province; end
      if isfield(aux_wlog,'state'),   wlog.state=aux_wlog.state;       end
      if isfield(aux_wlog,'county'),  wlog.county=aux_wlog.county;     end
      if isfield(aux_wlog,'country'), wlog.country=aux_wlog.country;   end
      if isfield(aux_wlog,'service'), wlog.service=aux_wlog.service;   end
      if isfield(aux_wlog,'uwi'),     wlog.uwi=aux_wlog.uwi;           end
   else
      disp('Input parameter "aux_wlog" is not a structure.')
   end
end