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1 ## Copyright (C) 1998 John W. Eaton |
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2 ## |
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3 ## This file is part of Octave. |
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4 ## |
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5 ## Octave is free software; you can redistribute it and/or modify it |
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6 ## under the terms of the GNU General Public License as published by |
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7 ## the Free Software Foundation; either version 2, or (at your option) |
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8 ## any later version. |
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9 ## |
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10 ## Octave is distributed in the hope that it will be useful, but |
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11 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 ## General Public License for more details. |
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14 ## |
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15 ## You should have received a copy of the GNU General Public License |
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16 ## along with Octave; see the file COPYING. If not, write to the Free |
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17 ## Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
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18 ## 02111-1307, USA. |
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19 |
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20 ## -*- texinfo -*- |
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21 ## @deftypefn {Function File} {} dot (@var{x}, @var{y}, @var{dim}) |
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22 ## Computes the dot product of two vectors. If @var{x} and @var{y} |
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23 ## are matrices, calculate the dot-product along the first |
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24 ## non-singleton dimension. If the optional argument @var{dim} is |
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25 ## given, calculate the dot-product along this dimension. |
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26 ## @end deftypefn |
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27 |
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28 ## Author: jwe |
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29 |
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30 function z = dot (x, y, dim) |
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31 |
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32 if (nargin != 2 && nargin != 3) |
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33 usage ("dot (x, y, dim)"); |
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34 endif |
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35 |
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36 if (nargin < 3) |
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37 if isvector (x) |
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38 x = x(:); |
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39 endif |
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40 if isvector (y) |
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41 y = y(:); |
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42 endif |
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43 if (size (x) != size (y)) |
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44 error ("dot: sizes of arguments must match") |
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45 endif |
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46 z = sum(x .* y); |
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47 else |
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48 if (size (x) != size (y)) |
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49 error ("dot: sizes of arguments must match") |
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50 endif |
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51 z = sum(x .* y, dim); |
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52 endif |
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53 |
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54 endfunction |
