%uneval - Create eval'able string from a variable.
%
%string = uneval(value);
%string = uneval('varname', value);
%string = uneval('varname', value, false); % all lines concatenated
%strings = uneval('varname', value, true); % 1 line per string in cell entry
%
% Convert a MATLAB variable into a text string, which when evaluated,
% produces the original variable, and maintains machine precision for
% floating point values.
%
% This function handles many data types including structures of arrays of
% structurs but errors on unknown data types such as classes.
%
% Contrived usage:
% settings = load('some_data.mat');
% string = uneval('settings2', settings)
% eval(string);
% disp(isequalwithequalnans(settings, settings2));
%
% WARNING --- This probably won't work with handles to nested functions.
% Jan 2007 - D. Holl - Initial coding.
% I needed this utility for various odds & ends.
function the_string = uneval(var_name, value, return_cell_array)
switch nargin
case 1
value=var_name;
var_name='';
return_cell_array=false;
case 2
return_cell_array=false;
end
badchars = escape_sprintf;
reallybadchars = setdiff(char([0:31 127:255]), badchars);
% Get a cell array of strings:
the_string = value2strings(var_name, value);
if ~return_cell_array
% Concatenate the strings with linefeeds after each:
the_string = cellstr2string(the_string);
else
% If the caller wanted cell array output, make sure it is a
% column vector instead of a row. (This is the standard for
% MATLAB's multiline edit-text uicontrols.)
the_string = the_string(:);
end
return;
function strings = value2strings(var_name, value)
strings = {};
switch class(value)
case {'int8', 'uint8', 'int16', 'uint16', 'int32', 'uint32', 'int64', 'uint64','single','double'}
if isa(value, 'double')
type_str1 = '';
mat2str_args = {17}; % I ask for 17 digits to preserve doubles, and we don't need 'class' because MATLAB defaults to double.
elseif isa(value, 'single')
type_str1 = ', ''single''';
mat2str_args = {8, 'class'}; % I ask for 8 digits to preserve singles
else
type_str1 = [', ''' class(value) ''''];
mat2str_args = {'class'};
end
% mat2str also handles complex!
if numel(value)>4 && all(arrayfun(@(x)isequalwithequalnans(value(1), x), value(:))) % make sure all elements are the same
switch value(1)
case 1
strings{end+1} = ['ones(' mat2str(size(value)) type_str1 ')'];
case -1
strings{end+1} = ['-ones(' mat2str(size(value)) type_str1 ')'];
case 0
strings{end+1} = ['zeros(' mat2str(size(value)) type_str1 ')'];
case inf
strings{end+1} = ['inf(' mat2str(size(value)) type_str1 ')'];
case -inf
strings{end+1} = ['-inf(' mat2str(size(value)) type_str1 ')'];
otherwise
if isnan(value(1)) % Because "case nan" doesn't work. (nan==nan is false)
strings{end+1} = ['nan(' mat2str(size(value)) type_str1 ')'];
else
strings{end+1} = ['repmat(' mat2str(value(1),mat2str_args{:}) ', ' mat2str(size(value)) ')']; %don't need 'class' because MATLAB defaults to double
end
end
else
if ndims(value)>2
% mat2str cannot handle ndims>2, so we flatten
% value(:,:), and then output with reshape:
strings{end+1} = ['reshape(' mat2str(value(:,:),mat2str_args{:}) ', ' mat2str(size(value)) ')'];
else
strings{end+1} = mat2str(value,mat2str_args{:});
end
end
if ~isempty(var_name), strings{end} = sprintf('%s=%s;', var_name, strings{end}); end
case 'char'
value_size = size(value);
% Hack for char matrices: make 'em look like rows:
value = value(:).';
if any(ismember(reallybadchars, value))
% If they're really bad, convert them all to numbers:
strings{end+1} = ['char(' mat2str(double(value)) ')'];
elseif any(ismember(badchars, value))
% If they're only a little bad, wrap them with sprintf:
strings{end+1} = ['sprintf(''' escape_sprintf(value) ''')'];
else
% The string must be safe:
strings{end+1} = ['''' value ''''];
end
% Now we preserve the original dimensions somehow:
if numel(value_size)==2 && value_size(1)~=1 && value_size(2)==1
% This is a column vector, so add a .' to the end:
strings{end} = [strings{end} '.'''];
elseif numel(value_size)>2 || value_size(1)~=1
% This is either 2-D or higher dimensional:
strings{end} = ['reshape(' strings{end} ', ' mat2str(value_size) ')'];
end
if ~isempty(var_name), strings{end} = sprintf('%s=%s;', var_name, strings{end}); end
case 'logical'
% I could group logicals with the numeric types, but that would
% produce: [true false true true ...] instead of [1 0 1 1 ...].
if numel(value)>4 && all(value(1)==value(:)) % make sure all elements are the same
if value(1)
strings{end+1} = ['true(' mat2str(size(value)) ')'];
else
strings{end+1} = ['false(' mat2str(size(value)) ')'];
end
else
if ndims(value)>2
% mat2str cannot handle ndims>2, so we flatten
% value(:,:), and then output with reshape:
strings{end+1} = ['reshape(logical(' mat2str(double(value(:,:))) '), ' mat2str(size(value)) ')'];
else
strings{end+1} = ['logical(' mat2str(double(value)) ')'];
end
end
if ~isempty(var_name), strings{end} = sprintf('%s=%s;', var_name, strings{end}); end
case 'function_handle'
% WARNING --- This probably won't work with handles to nested
% functions.
strings{end+1} = func2str(value);
if ~isempty(var_name), strings{end} = sprintf('%s=%s;', var_name, strings{end}); end
case 'struct'
value_size = size(value);
if prod(value_size)==1
strings{end+1} = 'struct';
else
strings{end+1} = ['repmat(struct, ' mat2str(value_size) ')'];
end
if ~isempty(var_name), strings{end} = sprintf('%s=%s;', var_name, strings{end}); end
fields = fieldnames(value);
for ndx=1:numel(value)
if numel(value)==1
subscripts = '';
elseif numel(value_size)==2 && any(value_size==1)
subscripts = sprintf('(%i)', ndx);
else
subscripts = cell_ind2sub(value_size, ndx);
subscripts = sprintf('(%i%s)', subscripts(1), sprintf(',%i',subscripts(2:end)));
end
for fndx=1:numel(fields)
sub_strings = value2strings(sprintf('%s%s.%s', var_name, subscripts, fields{fndx}), value(ndx).(fields{fndx}));
strings = {strings{:}, sub_strings{:}};%#ok
end
end
case 'cell'
value_size = size(value);
strings{end+1} = ['cell(' mat2str(value_size) ')'];
if ~isempty(var_name), strings{end} = sprintf('%s=%s;', var_name, strings{end}); end
for ndx=1:numel(value)
if numel(value_size)==2 && any(value_size==1)
subscripts = sprintf('{%i}', ndx);
else
subscripts = cell_ind2sub(value_size, ndx);
subscripts = sprintf('{%i%s}', subscripts(1), sprintf(',%i',subscripts(2:end)));
end
sub_strings = value2strings(sprintf('%s%s', var_name, subscripts), value{ndx});
strings = {strings{:}, sub_strings{:}};%#ok
end
otherwise
error('uneval:unknown_class', 'Unknown class "%s", ', class(value));
end
end
end
%escape_sprintf - Escape a string to be used for sprintf formatting.
%
%string = escape_sprintf(string);
%badchars = escape_sprintf;
% Replace any "bad" characters in a string with sprintf escapes.
% If called with no input, return the list of characters that we'll replace.
%
% 1/2007 - D. Holl
function string = escape_sprintf(string)
% \\ must come BEFORE the other \ codes.
char_list = {'''', '%%', '\\', '\b', '\f', '\n', '\r', '\t'};
if nargin==0
string = sprintf([char_list{:}]);
else
for ndx=1:numel(char_list)
char = sprintf(char_list{ndx});
string = strrep(string, char, char_list{ndx});
end
end
end
%CELLSTR2STRING - Concatenate multi-line array of strings into one string.
function the_string = cellstr2string(the_cellstr)
% Concatenate the strings with linefeeds after each:
LF = sprintf('\n');
the_cellstr = cellfun(@(x)[x LF], the_cellstr, 'UniformOutput', false);
the_string = [the_cellstr{:}];
end
%CELL_IND2SUB Multiple subscripts from linear index.
% CELL_IND2SUB is used to determine the equivalent subscript values
% corresponding to a given single index into an array. This function
% is identical to MATLAB's IND2SUB except that it returns all subscripts
% as a single array.
%
% 3/2007 - D. Holl
function subscripts = cell_ind2sub(siz,ndx)
siz = double(siz);
subscripts = nan(size(siz));
k = [1 cumprod(siz(1:end-1))];
for i = numel(siz):-1:1,
vi = rem(ndx-1, k(i)) + 1;
vj = (ndx - vi)/k(i) + 1;
subscripts(i) = vj;
ndx = vi;
end
