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1 ## Copyright (C) 1995, 1996 Kurt Hornik |
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2 ## |
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3 ## This program is free software; you can redistribute it and/or modify |
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4 ## it under the terms of the GNU General Public License as published by |
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5 ## the Free Software Foundation; either version 2, or (at your option) |
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6 ## any later version. |
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7 ## |
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8 ## This program is distributed in the hope that it will be useful, but |
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9 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
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10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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11 ## General Public License for more details. |
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12 ## |
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13 ## You should have received a copy of the GNU General Public License |
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14 ## along with this file. If not, write to the Free Software Foundation, |
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15 ## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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16 |
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17 ## usage: nextpow2 (x) |
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18 ## |
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19 ## If x is a scalar, returns the first integer n such that |
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20 ## 2^n >= abs (x). |
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21 ## |
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22 ## If x is a vector, return nextpow2 (length (x)). |
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23 |
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24 ## Author: KH <Kurt.Hornik@ci.tuwien.ac.at> |
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25 ## Created: 7 October 1994 |
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26 ## Adapted-By: jwe |
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27 |
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28 function n = nextpow2 (x) |
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29 |
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30 if (nargin != 1) |
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31 usage ("nextpow2 (x)"); |
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32 endif |
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33 |
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34 if (is_vector (x)) |
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35 x = length (x); |
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36 elseif (! is_scalar (x)) |
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37 error ("nextpow2: x must be a scalar or a vector"); |
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38 endif |
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39 |
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40 [f, n] = log2 (abs (x)); |
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41 if (f == 0.5) |
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42 n = n - 1; |
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43 endif |
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44 |
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45 endfunction |
