0001 function y = convert_img_units(img,arg1,arg2)
0002
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0018
0019 if ischar(img) && strcmp(img,'UNIT_TEST'); y = do_unit_test; return; end
0020
0021 if nargin < 2
0022 error('EIDORS:ConvertUnits:Input', ...
0023 'Not enough input arguments.');
0024 end
0025
0026
0027 if isnumeric(img)
0028
0029 if nargin < 3
0030 error('EIDORS:ConvertUnits:Input', ...
0031 'Two units are required to convert numeric values.');
0032 else
0033 x = img;
0034 cur_unit = arg1;
0035 new_unit = arg2;
0036 y = map_data(x, cur_unit, new_unit);
0037 return
0038 end
0039 end
0040
0041
0042 if any(isfield(img,{'elem_data','node_data'}))
0043 if nargin == 3
0044 cur_unit = arg1;
0045 new_unit = arg2;
0046 else
0047 try
0048 cur_unit = img.current_params;
0049 new_unit = arg1;
0050 catch
0051 error(['Don''t know what to convert. '...
0052 'Need either 3 arguments or img.current_params.']);
0053 end
0054 end
0055 else
0056 if nargin ==3
0057 cur_unit = arg1;
0058 img.data_mapper = cur_unit;
0059 new_unit = arg2;
0060 else
0061 new_unit = arg1;
0062 end
0063 img = data_mapper(img);
0064 cur_unit = img.current_params;
0065
0066
0067
0068 end
0069
0070
0071 [x do_nodes] = get_data(img);
0072
0073 y = map_data(x, cur_unit, new_unit);
0074
0075
0076 if do_nodes
0077 img.node_data = y;
0078 else
0079 img.elem_data = y;
0080 end
0081 img.current_params = new_unit;
0082 y = img;
0083
0084 end
0085
0086 function x = map_data(x, cur_unit, new_unit)
0087
0088 if isempty(cur_unit) || isempty(new_unit)
0089 error('Unit string must not be empty.');
0090 end
0091
0092 if strcmp(cur_unit, new_unit)
0093 return
0094 end
0095
0096 f = str2func(sprintf('%s2%s',cur_unit,new_unit));
0097 try
0098 x = feval(f,x);
0099 x = fix_and_test(x);
0100 catch err
0101 if strcmp(err.identifier,'MATLAB:UndefinedFunction')
0102 cur_pre = regexp(cur_unit,'^(.*?)_','match');
0103 if ~isempty(cur_pre) && ismember(cur_pre{1}, {'log_', 'log10_'});
0104 l = length(cur_pre{1});
0105 x = reverse(cur_pre{1}, x);
0106 x = map_data(x, cur_unit(l+1:end), new_unit);
0107 x = fix_and_test(x);
0108 return
0109 end
0110 new_pre = regexp(new_unit,'^(.*?)_','match');
0111 if ~isempty(new_pre) && ismember(new_pre{1}, {'log_', 'log10_', 'abs_'});
0112 l = length(new_pre{1});
0113 x = map_data(x, cur_unit, new_unit(l+1:end));
0114 x = apply(new_pre{1}, x);
0115 x = fix_and_test(x);
0116 return
0117 end
0118
0119
0120 error('EIDORS:ConversionNotSupported', errorstr(cur_unit, new_unit));
0121 else
0122 rethrow(err);
0123 end
0124 end
0125
0126 end
0127
0128 function x = fix_and_test(x)
0129 x(x == +inf) = +realmax;
0130 x(x == -inf) = -realmax;
0131 err_if_inf_or_nan(x, 'map_data-post');
0132 end
0133
0134 function err_if_inf_or_nan(x, str)
0135 if any(isnan(x) | isinf(x))
0136 error(sprintf('bad %s (%d NaN, %d Inf of %d)', ...
0137 str, ...
0138 length(find(isnan(x))), ...
0139 length(find(isinf(x))), ...
0140 length(x)));
0141 end
0142
0143 end
0144
0145 function x = conductivity2resistivity(x)
0146 x = 1./x;
0147 end
0148
0149 function x = resistivity2conductivity(x)
0150 x = 1./x;
0151 end
0152
0153 function erstr = errorstr(cur_unit, new_unit)
0154 erstr = sprintf( ['Unit conversion from %s to %s is not supported.\n'...
0155 'Please write a function %s2%s.'], cur_unit, new_unit, cur_unit, new_unit);
0156 end
0157
0158 function x = reverse(str, x);
0159 switch str
0160 case 'log10_'
0161 if any(x >= log10(realmax)-eps) warning('loss of precision -> inf'); end
0162 x = 10.^x;
0163 case 'log_'
0164 if any(x >= log(realmax)-eps) warning('loss of precision -> inf'); end
0165 x = exp(x);
0166 otherwise
0167 error('Cannot reverse %s', str);
0168 end
0169 end
0170
0171
0172 function x = apply(str, x)
0173 switch str
0174 case 'log10_'
0175 if any(x <= 0 + eps) warning('loss of precision -> -inf'); end
0176 x = log10(x);
0177 case 'log_'
0178 if any(x <= 0 + eps) warning('loss of precision -> -inf'); end
0179 x = log(x);
0180 case 'abs_'
0181 x = abs(x);
0182 otherwise
0183 error('Cannot apply %s', str);
0184 end
0185 end
0186
0187 function [x, do_nodes] = get_data(img)
0188 do_nodes = 0;
0189 try
0190 x = img.elem_data;
0191 catch
0192 try
0193 x = img.node_data;
0194 do_nodes = 1;
0195 catch
0196 error('No elem_data or node_data found');
0197 end
0198 end
0199 end
0200
0201
0202 function pass = do_unit_test
0203 pass = 1;
0204 d = 1;
0205 while (d ~= 1) && (d ~= 0)
0206 d = rand(1);
0207 end
0208 disp('TEST: convert_img_units()');
0209 elem_types = {'conductivity', 'log_conductivity', 'log10_conductivity', ...
0210 'resistivity', 'log_resistivity', 'log10_resistivity'};
0211 expected = [d log(d) log10(d) 1./d log(1./d) log10(1./d); ...
0212 exp(d) d log10(exp(d)) 1./exp(d) log(1./exp(d)) log10(1./exp(d)); ...
0213 10.^d log(10.^d ) d 1./10.^d log(1./10.^d ) log10(1./10.^d ); ...
0214 1./d log(1./d ) log10(1./d) d log(d) log10(d); ...
0215 1./exp(d) log(1./exp(d)) log10(1./exp(d)) exp(d) d log10(exp(d)); ...
0216 1./10.^d log(1./10.^d) log10(1./10.^d) 10.^d log(10.^d) d ];
0217 for i = 1:length(elem_types)
0218 for j = 1:length(elem_types)
0219 pass = test_map_data(d, elem_types{i}, elem_types{j}, expected(i,j), pass);
0220 end
0221 end
0222
0223 if pass
0224 disp('TEST: overall PASS');
0225 else
0226 disp('TEST: overall FAIL');
0227 end
0228 end
0229
0230
0231 function pass = test_map_data(data, in, out, expected, pass)
0232 fprintf('TEST: convert_img_units(%s -> %s)\n', in, out);
0233 if convert_img_units(data, in, out) ~= expected
0234 pass = 0;
0235 fprintf('TEST: FAIL convert_img_units(%s -> %s)\n', in, out);
0236 end
0237 end