[37] | 1 | function write(filename, format, a) |
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| 2 | % WRITE Output a quaternion array to a text file. |
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| 3 | % |
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| 4 | % write(filename, format, a) |
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| 5 | % |
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| 6 | % This function writes a text file which is designed to be easily |
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| 7 | % read into other software, such as Maple, Mathematica, etc. The |
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| 8 | % first line of the file contains two integer values giving the |
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| 9 | % number of rows and columns in the file. The quaternion values |
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| 10 | % then follow in raster order, that is with the column index varying |
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| 11 | % most rapidly. Each quaternion value occupies one line in the file, |
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| 12 | % and consists of four floating-point values, separated by spaces. |
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| 13 | % |
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| 14 | % The format parameter may be omitted, in which case a default is |
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| 15 | % assumed which outputs sufficient digits to represent double values |
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| 16 | % with no loss of accuracy. Otherwise the format is a string (see the |
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| 17 | % standard Matlab function fprintf for details). |
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| 18 | % |
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| 19 | % If the parameter a is a pure quaternion, only three components are |
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| 20 | % written per quaternion. |
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| 21 | |
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| 22 | % Copyright © 2005 Stephen J. Sangwine and Nicolas Le Bihan. |
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| 23 | % See the file : Copyright.m for further details. |
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| 24 | |
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| 25 | error(nargchk(2, 3, nargin)), error(nargoutchk(0, 0, nargout)) |
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| 26 | |
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| 27 | if nargin == 2 |
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| 28 | |
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| 29 | % Only two parameters have been supplied. The missing one must |
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| 30 | % be the format, since the other two cannot be omitted. Shuffle |
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| 31 | % the parameters, and supply the default value for the format. |
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| 32 | |
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| 33 | a = format; |
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| 34 | format = '%+24.16e'; |
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| 35 | end |
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| 36 | |
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| 37 | [r, c] = size(a); |
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| 38 | |
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| 39 | fid = fopen(filename, 'w'); |
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| 40 | |
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| 41 | fprintf(fid, '%8u %8u\n', r, c); |
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| 42 | fprintf(fid, format, a); |
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| 43 | fprintf(fid, '\n'); % For some reason the last \n gets omitted in the previous line. |
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| 44 | |
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| 45 | if fclose(fid) |
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| 46 | error('The file was not written successfully.'); |
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| 47 | end |
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