convert.m

这是一个关于MATLAB的函数

function mm = convert(mm,datatype,siz)
%CONVERT  Configures properties for predefined target data types
%   CONVERT(MM,TYPE) - Defines the numeric representation to be
%   applied to the register object MM.  The TYPE input defines 
%   some common data types.  This method adjusts the properties
%   of MM object to match the specified TYPE.  As a result,
%   future READ/WRITE operations will apply the appropriate
%   data conversion to implement the numeric representation.
%   For uncommon datatypes, it is possible to directly modify
%   the MM properties, but generally it is better to use the CONVERT
%   method.
% 
%   CONVERT(MM,TYPE,SIZE) - Does an additional reshaping - adjusts the 
%   'size' property - of the MM object.
%
%   Note: SIZE is always 1 for bit fields.
%
%   See also CAST, COPY.

%   Copyright 2002 The MathWorks, Inc.
%   $Revision: 1.5 $ $Date: 2002/05/13 18:31:50 $

error(nargchk(2,3,nargin));
if ~ishandle(mm),
    error('First Parameter must be a BITFIELD Handle.');
end
if ~ischar(datatype),
     error('Second Parameter must be a string.');
end
if nargin==3
	if ~isnumeric(siz),
         error('Third Parameter must be numeric.');
    else
        if prod(siz)~=1
            error('Bitfield cannot have size>1 ');
        end
    end    
end

% Change to specified datatype
mm.prepad  = 0;  % Modified later, if necessary
mm.postpad = 0;

switch datatype
case 'int'
    if strcmp(mm.procsubfamily(1:2),'C6'), % C6x
        totalbits  = 32;
    elseif strcmp(mm.procsubfamily,'C54x'), % C5x
        totalbits  = 16;        
    end
    mm.storageunitspervalue = round(totalbits/mm.bitsperstorageunit);
    mm.represent = 'signed';
case 'unsigned int'
    if strcmp(mm.procsubfamily(1:2),'C6'), % C6x
        totalbits  = 32;
    elseif strcmp(mm.procsubfamily,'C54x'), % C5x
        totalbits  = 16;
    end
    mm.storageunitspervalue = round(totalbits/mm.bitsperstorageunit);
    mm.represent = 'unsigned';
otherwise,
    error(['DATATYPE:' datatype ' is not supported']);
end

% reshape size (to 1)
if nargin==3, set(mm,'size',siz); end;  

% [EOF] convert.m