tally: new module for tallying numbers.

[ccan] / ccan / tally / test / run-histogram.c

diff --git a/ccan/tally/test/run-histogram.c b/ccan/tally/test/run-histogram.c
new file mode 100644 (file)
index 0000000..8f8bd2f
--- /dev/null
+++ b/ccan/tally/test/run-histogram.c
@@ -0,0 +1,112 @@
+#include <ccan/tally/tally.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+       int i;
+       struct tally *tally;
+       char *graph, *p;
+       bool trunc;
+
+       plan_tests(100 + 1 + 10 + 1 + 100 + 1 + 10 + 1 + 10 + 2 + 1);
+
+       /* Uniform distribution, easy. */
+       tally = tally_new(100);
+       for (i = 0; i < 100; i++)
+               tally_add(tally, i);
+
+       /* 1:1 height. */
+       graph = p = tally_histogram(tally, 20, 100);
+       for (i = 0; i < 100; i++) {
+               char *eol = strchr(p, '\n');
+
+               /* We expect it filled all way to the end. */
+               ok1(eol - p == 20);
+               p = eol + 1;
+       }
+       ok1(!*p);
+       free(graph);
+
+       /* Reduced height. */
+       trunc = false;
+       graph = p = tally_histogram(tally, 20, 10);
+       for (i = 0; i < 10; i++) {
+               char *eol = strchr(p, '\n');
+
+               /* Last once can be truncated (bucket aliasing) */
+               if (eol) {
+                       if (eol - p < 20) {
+                               ok1(!trunc);
+                               trunc = true;
+                       } else if (eol - p == 20) {
+                               ok1(!trunc);
+                       } else {
+                               fail("Overwidth line %s", p);
+                       }
+               } else
+                       /* We should, at worst, half-fill graph */
+                       ok1(i > 5);
+
+               if (eol)
+                       p = eol + 1;
+       }
+       ok1(!*p);
+       free(graph);
+
+       /* Enlarged height (gets capped). */
+       graph = p = tally_histogram(tally, 20, 1000);
+       for (i = 0; i < 100; i++) {
+               char *eol = strchr(p, '\n');
+               /* We expect it filled all way to the end. */
+               ok1(eol - p == 20);
+               p = eol + 1;
+       }
+       ok1(!*p);
+       free(graph);
+       free(tally);
+
+       /* Distinctive increasing pattern. */
+       tally = tally_new(10);
+       for (i = 0; i < 10; i++) {
+               unsigned int j;
+               for (j = 0; j <= i; j++)
+                       tally_add(tally, i);
+       }
+
+       graph = p = tally_histogram(tally, 10, 10);
+       for (i = 0; i < 10; i++) {
+               char *eol = strchr(p, '\n');
+               ok1(eol - p == i+1);
+               p = eol + 1;
+       }
+       ok1(!*p);
+       diag("Here's the pretty: %s", graph);
+       free(graph);
+       free(tally);
+
+       /* With negative values. */
+       tally = tally_new(10);
+       for (i = 0; i < 10; i++) {
+               tally_add(tally, i - 5);
+       }
+
+       graph = p = tally_histogram(tally, 10, 10);
+       for (i = 0; i < 10; i++) {
+               char *eol = strchr(p, '\n');
+
+               /* We expect it filled all way to the end. */
+               ok1(eol - p == 10);
+
+               /* Check min/max labels. */
+               if (i == 0)
+                       ok1(strncmp(p, "-5*", 3) == 0);
+               if (i == 9)
+                       ok1(strncmp(p, "4*", 2) == 0);
+               p = eol + 1;
+       }
+       ok1(!*p);
+       free(graph);
+       free(tally);
+
+       return exit_status();
+}