32 lines
831 B
C
32 lines
831 B
C
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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/* This program evaluates the integral of exp(x) in [0;1] through the
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* trapezoidal rule.
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* The integration step is given in input as d in step = 1e-d.
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*
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*/
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int main(int argc, char** argv){
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double left = 0; // left limit
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double point = left; // points at the current position
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double right = 1; // right limit
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double step = pow(10, -atoi(argv[1])); // step of integration
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double sum = 0;
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// Integral evaluation: stops when point goes over the right edge of the
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// range.
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do {
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sum += step * 0.5 * (exp(point) + exp(point + step));
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point += step;
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} while (point < right);
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// Print out the result
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printf("∫exp(x)dx in [0,1]:\t%.7f\n", sum);
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return EXIT_SUCCESS;
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}
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