Fivenum: Difference between revisions
Added C
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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.
=={{header|C}}==
{{trans|Kotlin}}
<lang c>#include <stdio.h>
#include <stdlib.h>
double median(double *x, int start, int end_inclusive) {
int size = end_inclusive - start + 1;
if (size <= 0) {
printf("Array slice cannot be empty\n");
exit(1);
}
int m = start + size / 2;
if (size % 2) return x[m];
return (x[m - 1] + x[m]) / 2.0;
}
int compare (const void *a, const void *b) {
double aa = *(double*)a;
double bb = *(double*)b;
if (aa > bb) return 1;
if (aa < bb) return -1;
return 0;
}
int fivenum(double *x, double *result, int x_len) {
int i, m, lower_end;
for (i = 0; i < x_len; i++) {
if (x[i] != x[i]) {
printf("Unable to deal with arrays containing NaN\n\n");
return 1;
}
}
qsort(x, x_len, sizeof(double), compare);
result[0] = x[0];
result[2] = median(x, 0, x_len - 1);
result[4] = x[x_len - 1];
m = x_len / 2;
lower_end = (x_len % 2) ? m : m - 1;
result[1] = median(x, 0, lower_end);
result[3] = median(x, m, x_len - 1);
return 0;
}
int show(double *result, int places) {
int i;
char f[7];
sprintf(f, "%%.%dlf", places);
printf("[");
for (i = 0; i < 5; i++) {
printf(f, result[i]);
if (i < 4) printf(", ");
}
printf("]\n\n");
}
int main() {
double result[5];
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};
if (!fivenum(x1, result, 11)) show(result, 1);
double x2[6] = {36.0, 40.0, 7.0, 39.0, 41.0, 15.0};
if (!fivenum(x2, result, 6)) show(result, 1);
double x3[20] = {
0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555,
-0.03035726, 1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527,
-0.98983780, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385,
0.75775634, 0.32566578
};
if (!fivenum(x3, result, 20)) show(result, 9);
return 0;
}</lang>
{{out}}
<pre>
[6.0, 25.5, 40.0, 42.5, 49.0]
[7.0, 15.0, 37.5, 40.0, 41.0]
[-1.950595940, -0.676741205, 0.233247060, 0.746070945, 1.731315070]
</pre>
=={{header|Kotlin}}==
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