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annotate scripts/polynomial/polyderiv.m @ 561:e79ff1f4df3c

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[project @ 1994-07-25 22:32:08 by jwe] Initial revision
author jwe
date Mon, 25 Jul 1994 22:32:08 +0000
parents
children 3470f1e25a79
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e79ff1f4df3c [project @ 1994-07-25 22:32:08 by jwe]
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1 function p = polyderiv(p)
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2 #polyderiv(c)
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3 #Returns the coefficients of the derivative of the polynomial whose
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4 #coefficients are given by vector c.
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5 #
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6 #SEE ALSO: poly, polyinteg, polyreduce, roots, conv, deconv, residue,
e79ff1f4df3c [project @ 1994-07-25 22:32:08 by jwe]
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7 # filter, polyval, polyvalm
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8
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9 # Author:
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10 # Tony Richardson
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11 # amr@mpl.ucsd.edu
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12 # June 1994
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13
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14 if(nargin != 1)
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15 error("usage: polyderiv(vector)");
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16 endif
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17
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18 if(is_matrix(p))
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19 error("argument must be a vector");
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20 endif
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21
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22 lp = length(p);
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23 if(lp == 1)
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24 p = 0;
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25 return;
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26 elseif (lp == 0)
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27 p = [];
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28 return;
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29 end
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30
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31 p = p(1:(lp-1)) .* [(lp-1):-1:1];
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32
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33 endfunction