Fivenum: Difference between revisions
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(→{{header|Kotlin}}: Made more efficient - no intermediate lists.) |
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Given a large array, reduce a large array to five numbers that will have the same boxplot properties as the larger array. |
Given a large array, reduce a large array to five numbers that will have the same boxplot properties as the larger array. |
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=={{header|C}}== |
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{{trans|Kotlin}} |
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<lang c>#include <stdio.h> |
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#include <stdlib.h> |
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double median(double *x, int start, int end_inclusive) { |
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int size = end_inclusive - start + 1; |
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if (size <= 0) { |
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printf("Array slice cannot be empty\n"); |
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exit(1); |
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} |
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int m = start + size / 2; |
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if (size % 2) return x[m]; |
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return (x[m - 1] + x[m]) / 2.0; |
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} |
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int compare (const void *a, const void *b) { |
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double aa = *(double*)a; |
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double bb = *(double*)b; |
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if (aa > bb) return 1; |
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if (aa < bb) return -1; |
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return 0; |
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} |
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int fivenum(double *x, double *result, int x_len) { |
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int i, m, lower_end; |
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for (i = 0; i < x_len; i++) { |
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if (x[i] != x[i]) { |
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printf("Unable to deal with arrays containing NaN\n\n"); |
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return 1; |
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} |
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} |
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qsort(x, x_len, sizeof(double), compare); |
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result[0] = x[0]; |
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result[2] = median(x, 0, x_len - 1); |
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result[4] = x[x_len - 1]; |
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m = x_len / 2; |
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lower_end = (x_len % 2) ? m : m - 1; |
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result[1] = median(x, 0, lower_end); |
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result[3] = median(x, m, x_len - 1); |
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return 0; |
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} |
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int show(double *result, int places) { |
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int i; |
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char f[7]; |
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sprintf(f, "%%.%dlf", places); |
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printf("["); |
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for (i = 0; i < 5; i++) { |
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printf(f, result[i]); |
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if (i < 4) printf(", "); |
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} |
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printf("]\n\n"); |
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} |
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int main() { |
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double result[5]; |
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double x1[11] = {15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0}; |
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if (!fivenum(x1, result, 11)) show(result, 1); |
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double x2[6] = {36.0, 40.0, 7.0, 39.0, 41.0, 15.0}; |
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if (!fivenum(x2, result, 6)) show(result, 1); |
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double x3[20] = { |
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0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555, |
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-0.03035726, 1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527, |
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-0.98983780, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, |
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0.75775634, 0.32566578 |
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}; |
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if (!fivenum(x3, result, 20)) show(result, 9); |
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return 0; |
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}</lang> |
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{{out}} |
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<pre> |
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[6.0, 25.5, 40.0, 42.5, 49.0] |
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[7.0, 15.0, 37.5, 40.0, 41.0] |
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[-1.950595940, -0.676741205, 0.233247060, 0.746070945, 1.731315070] |
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</pre> |
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=={{header|Kotlin}}== |
=={{header|Kotlin}}== |