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{ RCSid $Id$ } |
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{ |
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root.cal - calculate zeroes of functions using Newton's method. |
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2/3/88 |
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} |
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FTINY : 1e-12; |
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root(f, x0) = root2(f, x0, x0-f(x0)/lim(f1(f,x0)), nit); |
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root2(f, x0, x1, i) = if(i, |
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if(err-abs(x1-x0), |
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x1, |
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root2(f,x1,x1-f(x1)/lim(f1(f,x1)),i-1)), |
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0); |
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abs(x) = if(x, x, -x); |
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lim(x) = if(x, max(x,err), -max(-x,err)); |
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max(a,b) = if(a-b, a, b); |
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f1(f,x) = (f(x+FTINY)-f(x-FTINY))/(2*FTINY); { numerical derivative } |
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err = 1e-6; |
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nit = 100; |
