21 lines
346 B
C
21 lines
346 B
C
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#include <math.h>
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double _agm(double x, double y) {
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double a = x;
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double g = y;
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double temp;
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for(int i = 0; i < 15; i++) {
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temp = 0.5 * (a + g);
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g = sqrt(a * g);
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a = temp;
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}
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return a;
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}
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double log(double x) {
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double s = x * exp2(24);
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double nat_log = (M_PI / (2 * _agm(1, 4/s))) - (24 * M_LN2);
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return nat_log;
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}
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