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annotate scripts/polynomial/polyderiv.m @ 904:3470f1e25a79

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[project @ 1994-11-09 21:22:15 by jwe]
author jwe
date Wed, 09 Nov 1994 21:22:15 +0000
parents e79ff1f4df3c
children f558749713f1
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1 function p = polyderiv(p)
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2
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3 # polyderiv(c)
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4 # Returns the coefficients of the derivative of the polynomial whose
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5 # coefficients are given by vector c.
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6 #
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7 # SEE ALSO: poly, polyinteg, polyreduce, roots, conv, deconv, residue,
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8 # filter, polyval, polyvalm
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9
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10 # Author:
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11 # Tony Richardson
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12 # amr@mpl.ucsd.edu
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13 # June 1994
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14
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15 if(nargin != 1)
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16 usage ("polyderiv(vector)");
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17 endif
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18
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19 if(is_matrix(p))
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20 error("argument must be a vector");
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21 endif
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22
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23 lp = length(p);
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24 if(lp == 1)
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25 p = 0;
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26 return;
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27 elseif (lp == 0)
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28 p = [];
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29 return;
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30 end
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31
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32 p = p(1:(lp-1)) .* [(lp-1):-1:1];
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33
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34 endfunction