From 8df91660bfbcd378b081c6ff028768bcda692523 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Mon, 3 Jun 2019 17:31:12 +0200
Subject: [PATCH] hist: port to C++
---
common/include/villas/hist.hpp | 136 +++++++++++---------
common/lib/hist.cpp | 219 ++++++++++++++++-----------------
common/tests/unit/hist.cpp | 17 ++-
3 files changed, 194 insertions(+), 178 deletions(-)
diff --git a/common/include/villas/hist.hpp b/common/include/villas/hist.hpp
index b4a2b68b5..11adef22d 100644
--- a/common/include/villas/hist.hpp
+++ b/common/include/villas/hist.hpp
@@ -1,4 +1,4 @@
-/** Histogram functions.
+/** Histogram class.
*
* @file
* @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
@@ -28,13 +28,81 @@
#include <jansson.h>
-#define HIST_HEIGHT (LOG_WIDTH - 55)
-#define HIST_SEQ 17
+#define HEIGHT (LOG_WIDTH - 55)
+#define SEQ 17
-typedef uintmax_t hist_cnt_t;
+namespace villas {
/** Histogram structure used to collect statistics. */
-struct hist {
+class Hist {
+
+public:
+ using cnt_t = uintmax_t;
+
+ /** Initialize struct hist with supplied values and allocate memory for buckets. */
+ Hist(int buckets, cnt_t warmup);
+
+ /** Free the dynamically allocated memory. */
+ ~Hist();
+
+ /** Reset all counters and values back to zero. */
+ void reset();
+
+ /** Count a value within its corresponding bucket. */
+ void put(double value);
+
+ /** Calcluate the variance of all counted values. */
+ double getVar() const;
+
+ /** Calculate the mean average of all counted values. */
+ double getMean() const;
+
+ /** Calculate the standard derivation of all counted values. */
+ double getStddev() const;
+
+ /** Print all statistical properties of distribution including a graphilcal plot of the histogram. */
+ void print(const int details) const;
+
+ /** Print ASCII style plot of histogram */
+ void plot() const;
+
+ /** Dump histogram data in Matlab format.
+ *
+ * @return The string containing the dump. The caller is responsible to free() the buffer.
+ */
+ char * dump() const;
+
+ /** Prints Matlab struct containing all infos to file. */
+ int dumpMatlab(FILE *f) const;
+
+ /** Write the histogram in JSON format to fiel \p f. */
+ int dumpJson(FILE *f) const;
+
+ /** Build a libjansson / JSON object of the histogram. */
+ json_t * toJson() const;
+
+ double getHigh() const
+ {
+ return high;
+ }
+ double getLow() const
+ {
+ return low;
+ }
+ double getHighest() const
+ {
+ return highest;
+ }
+ double getLowest() const
+ {
+ return lowest;
+ }
+ double getLast() const
+ {
+ return last;
+ }
+
+protected:
double resolution; /**< The distance between two adjacent buckets. */
double high; /**< The value of the highest bucket. */
@@ -46,60 +114,16 @@ struct hist {
int length; /**< The number of buckets in #data. */
- hist_cnt_t total; /**< Total number of counted values. */
- hist_cnt_t warmup; /**< Number of values which are used during warmup phase. */
+ cnt_t total; /**< Total number of counted values. */
+ cnt_t warmup; /**< Number of values which are used during warmup phase. */
- hist_cnt_t higher; /**< The number of values which are higher than #high. */
- hist_cnt_t lower; /**< The number of values which are lower than #low. */
+ cnt_t higher; /**< The number of values which are higher than #high. */
+ cnt_t lower; /**< The number of values which are lower than #low. */
- hist_cnt_t *data; /**< Pointer to dynamically allocated array of size length. */
+
+ cnt_t *data; /**< Pointer to dynamically allocated array of size length. */
double _m[2], _s[2]; /**< Private variables for online variance calculation */
};
-#define hist_last(h) ((h)->last)
-#define hist_highest(h) ((h)->highest)
-#define hist_lowest(h) ((h)->lowest)
-#define hist_total(h) ((h)->total)
-
-/** Initialize struct hist with supplied values and allocate memory for buckets. */
-int hist_init(struct hist *h, int buckets, hist_cnt_t warmup);
-
-/** Free the dynamically allocated memory. */
-int hist_destroy(struct hist *h);
-
-/** Reset all counters and values back to zero. */
-void hist_reset(struct hist *h);
-
-/** Count a value within its corresponding bucket. */
-void hist_put(struct hist *h, double value);
-
-/** Calcluate the variance of all counted values. */
-double hist_var(const struct hist *h);
-
-/** Calculate the mean average of all counted values. */
-double hist_mean(const struct hist *h);
-
-/** Calculate the standard derivation of all counted values. */
-double hist_stddev(const struct hist *h);
-
-/** Print all statistical properties of distribution including a graphilcal plot of the histogram. */
-void hist_print(const struct hist *h, int details);
-
-/** Print ASCII style plot of histogram */
-void hist_plot(const struct hist *h);
-
-/** Dump histogram data in Matlab format.
- *
- * @return The string containing the dump. The caller is responsible to free() the buffer.
- */
-char * hist_dump(const struct hist *h);
-
-/** Prints Matlab struct containing all infos to file. */
-int hist_dump_matlab(const struct hist *h, FILE *f);
-
-/** Write the histogram in JSON format to fiel \p f. */
-int hist_dump_json(const struct hist *h, FILE *f);
-
-/** Build a libjansson / JSON object of the histogram. */
-json_t * hist_json(const struct hist *h);
+} /* namespace villas */
diff --git a/common/lib/hist.cpp b/common/lib/hist.cpp
index c559931e2..888410ab4 100644
--- a/common/lib/hist.cpp
+++ b/common/lib/hist.cpp
@@ -1,4 +1,4 @@
-/** Histogram functions.
+/** Histogram class.
*
* @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
* @copyright 2014-2019, Institute for Automation of Complex Power Systems, EONERC
@@ -34,141 +34,134 @@
using namespace villas::utils;
-#define VAL(h, i) ((h)->low + (i) * (h)->resolution)
-#define INDEX(h, v) round((v - (h)->low) / (h)->resolution)
+namespace villas {
-int hist_init(struct hist *h, int buckets, hist_cnt_t warmup)
+Hist::Hist(int buckets, Hist::cnt_t wu)
{
- h->length = buckets;
- h->warmup = warmup;
+ length = buckets;
+ warmup = wu;
- h->data = (hist_cnt_t *) (buckets ? alloc(h->length * sizeof(hist_cnt_t)) : nullptr);
+ data = (Hist::cnt_t *) (buckets ? alloc(length * sizeof(Hist::cnt_t)) : nullptr);
- hist_reset(h);
-
- return 0;
+ Hist::reset();
}
-int hist_destroy(struct hist *h)
+Hist::~Hist()
{
- if (h->data) {
- free(h->data);
- h->data = nullptr;
- }
-
- return 0;
+ if (data)
+ free(data);
}
-void hist_put(struct hist *h, double value)
+void Hist::put(double value)
{
- h->last = value;
+ last = value;
/* Update min/max */
- if (value > h->highest)
- h->highest = value;
- if (value < h->lowest)
- h->lowest = value;
+ if (value > highest)
+ highest = value;
+ if (value < lowest)
+ lowest = value;
- if (h->total < h->warmup) {
+ if (total < warmup) {
}
- else if (h->total == h->warmup) {
- h->low = hist_mean(h) - 3 * hist_stddev(h);
- h->high = hist_mean(h) + 3 * hist_stddev(h);
- h->resolution = (h->high - h->low) / h->length;
+ else if (total == warmup) {
+ low = getMean() - 3 * getStddev();
+ high = getMean() + 3 * getStddev();
+ resolution = (high - low) / length;
}
else {
- int idx = INDEX(h, value);
+ int idx = round((value - low) / resolution);
/* Check bounds and increment */
- if (idx >= h->length)
- h->higher++;
+ if (idx >= length)
+ higher++;
else if (idx < 0)
- h->lower++;
- else if (h->data != nullptr)
- h->data[idx]++;
+ lower++;
+ else if (data != nullptr)
+ data[idx]++;
}
- h->total++;
+ total++;
/* Online / running calculation of variance and mean
* by Donald Knuthâs Art of Computer Programming, Vol 2, page 232, 3rd edition */
- if (h->total == 1) {
- h->_m[1] = h->_m[0] = value;
- h->_s[1] = 0.0;
+ if (total == 1) {
+ _m[1] = _m[0] = value;
+ _s[1] = 0.0;
}
else {
- h->_m[0] = h->_m[1] + (value - h->_m[1]) / h->total;
- h->_s[0] = h->_s[1] + (value - h->_m[1]) * (value - h->_m[0]);
+ _m[0] = _m[1] + (value - _m[1]) / total;
+ _s[0] = _s[1] + (value - _m[1]) * (value - _m[0]);
/* Set up for next iteration */
- h->_m[1] = h->_m[0];
- h->_s[1] = h->_s[0];
+ _m[1] = _m[0];
+ _s[1] = _s[0];
}
}
-void hist_reset(struct hist *h)
+void Hist::reset()
{
- h->total = 0;
- h->higher = 0;
- h->lower = 0;
+ total = 0;
+ higher = 0;
+ lower = 0;
- h->highest = -DBL_MAX;
- h->lowest = DBL_MAX;
+ highest = -DBL_MAX;
+ lowest = DBL_MAX;
- if (h->data)
- memset(h->data, 0, h->length * sizeof(unsigned));
+ if (data)
+ memset(data, 0, length * sizeof(unsigned));
}
-double hist_mean(const struct hist *h)
+double Hist::getMean() const
{
- return (h->total > 0) ? h->_m[0] : NAN;
+ return (total > 0) ? _m[0] : NAN;
}
-double hist_var(const struct hist *h)
+double Hist::getVar() const
{
- return (h->total > 1) ? h->_s[0] / (h->total - 1) : NAN;
+ return (total > 1) ? _s[0] / (total - 1) : NAN;
}
-double hist_stddev(const struct hist *h)
+double Hist::getStddev() const
{
- return sqrt(hist_var(h));
+ return sqrt(getVar());
}
-void hist_print(const struct hist *h, int details)
+void Hist::print(int details) const
{
- if (h->total > 0) {
- hist_cnt_t missed = h->total - h->higher - h->lower;
+ if (total > 0) {
+ Hist::cnt_t missed = total - higher - lower;
- info("Counted values: %ju (%ju between %f and %f)", h->total, missed, h->low, h->high);
- info("Highest: %g", h->highest);
- info("Lowest: %g", h->lowest);
- info("Mu: %g", hist_mean(h));
- info("1/Mu: %g", 1.0/hist_mean(h));
- info("Variance: %g", hist_var(h));
- info("Stddev: %g", hist_stddev(h));
+ info("Counted values: %ju (%ju between %f and %f)", total, missed, low, high);
+ info("Highest: %g", highest);
+ info("Lowest: %g", lowest);
+ info("Mu: %g", getMean());
+ info("1/Mu: %g", 1.0 / getMean());
+ info("Variance: %g", getVar());
+ info("Stddev: %g", getStddev());
- if (details > 0 && h->total - h->higher - h->lower > 0) {
- char *buf = hist_dump(h);
+ if (details > 0 && total - higher - lower > 0) {
+ char *buf =dump();
info("Matlab: %s", buf);
free(buf);
- hist_plot(h);
+ plot();
}
}
else
- info("Counted values: %ju", h->total);
+ info("Counted values: %ju", total);
}
-void hist_plot(const struct hist *h)
+void Hist::plot() const
{
- hist_cnt_t max = 1;
+ Hist::cnt_t max = 1;
/* Get highest bar */
- for (int i = 0; i < h->length; i++) {
- if (h->data[i] > max)
- max = h->data[i];
+ for (int i = 0; i < length; i++) {
+ if (data[i] > max)
+ max = data[i];
}
std::vector<TableColumn> cols = {
@@ -182,9 +175,9 @@ void hist_plot(const struct hist *h)
/* Print plot */
table.header();
- for (int i = 0; i < h->length; i++) {
- double value = VAL(h, i);
- hist_cnt_t cnt = h->data[i];
+ for (int i = 0; i < length; i++) {
+ double value = low + (i) * resolution;
+ Hist::cnt_t cnt = data[i];
int bar = cols[2].getWidth() * ((double) cnt / max);
char *buf = strf("%s", "");
@@ -197,47 +190,47 @@ void hist_plot(const struct hist *h)
}
}
-char * hist_dump(const struct hist *h)
+char * Hist::dump() const
{
char *buf = (char *) alloc(128);
strcatf(&buf, "[ ");
- for (int i = 0; i < h->length; i++)
- strcatf(&buf, "%ju ", h->data[i]);
+ for (int i = 0; i < length; i++)
+ strcatf(&buf, "%ju ", data[i]);
strcatf(&buf, "]");
return buf;
}
-json_t * hist_json(const struct hist *h)
+json_t * Hist::toJson() const
{
json_t *json_buckets, *json_hist;
json_hist = json_pack("{ s: f, s: f, s: i }",
- "low", h->low,
- "high", h->high,
- "total", h->total
+ "low", low,
+ "high", high,
+ "total", total
);
- if (h->total > 0) {
+ if (total > 0) {
json_object_update(json_hist, json_pack("{ s: i, s: i, s: f, s: f, s: f, s: f, s: f }",
- "higher", h->higher,
- "lower", h->lower,
- "highest", h->highest,
- "lowest", h->lowest,
- "mean", hist_mean(h),
- "variance", hist_var(h),
- "stddev", hist_stddev(h)
+ "higher", higher,
+ "lower", lower,
+ "highest", highest,
+ "lowest", lowest,
+ "mean", getMean(),
+ "variance", getVar(),
+ "stddev", getStddev()
));
}
- if (h->total - h->lower - h->higher > 0) {
+ if (total - lower - higher > 0) {
json_buckets = json_array();
- for (int i = 0; i < h->length; i++)
- json_array_append(json_buckets, json_integer(h->data[i]));
+ for (int i = 0; i < length; i++)
+ json_array_append(json_buckets, json_integer(data[i]));
json_object_set(json_hist, "buckets", json_buckets);
}
@@ -245,9 +238,9 @@ json_t * hist_json(const struct hist *h)
return json_hist;
}
-int hist_dump_json(const struct hist *h, FILE *f)
+int Hist::dumpJson(FILE *f) const
{
- json_t *j = hist_json(h);
+ json_t *j = Hist::toJson();
int ret = json_dumpf(j, f, 0);
@@ -256,29 +249,31 @@ int hist_dump_json(const struct hist *h, FILE *f)
return ret;
}
-int hist_dump_matlab(const struct hist *h, FILE *f)
+int Hist::dumpMatlab(FILE *f) const
{
fprintf(f, "struct(");
- fprintf(f, "'low', %f, ", h->low);
- fprintf(f, "'high', %f, ", h->high);
- fprintf(f, "'total', %ju, ", h->total);
- fprintf(f, "'higher', %ju, ", h->higher);
- fprintf(f, "'lower', %ju, ", h->lower);
- fprintf(f, "'highest', %f, ", h->highest);
- fprintf(f, "'lowest', %f, ", h->lowest);
- fprintf(f, "'mean', %f, ", hist_mean(h));
- fprintf(f, "'variance', %f, ", hist_var(h));
- fprintf(f, "'stddev', %f, ", hist_stddev(h));
+ fprintf(f, "'low', %f, ", low);
+ fprintf(f, "'high', %f, ", high);
+ fprintf(f, "'total', %ju, ", total);
+ fprintf(f, "'higher', %ju, ", higher);
+ fprintf(f, "'lower', %ju, ", lower);
+ fprintf(f, "'highest', %f, ", highest);
+ fprintf(f, "'lowest', %f, ", lowest);
+ fprintf(f, "'mean', %f, ", getMean());
+ fprintf(f, "'variance', %f, ", getVar());
+ fprintf(f, "'stddev', %f, ", getStddev());
- if (h->total - h->lower - h->higher > 0) {
- char *buf = hist_dump(h);
+ if (total - lower - higher > 0) {
+ char *buf = dump();
fprintf(f, "'buckets', %s", buf);
free(buf);
}
else
- fprintf(f, "'buckets', zeros(1, %d)", h->length);
+ fprintf(f, "'buckets', zeros(1, %d)", length);
fprintf(f, ")");
return 0;
}
+
+} /* namespace villas */
diff --git a/common/tests/unit/hist.cpp b/common/tests/unit/hist.cpp
index 541d55709..41ec005ef 100644
--- a/common/tests/unit/hist.cpp
+++ b/common/tests/unit/hist.cpp
@@ -27,21 +27,18 @@
const double test_data[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+using namespace villas;
+
TestSuite(hist, .description = "Histogram");
Test(hist, simple) {
- struct hist h;
- int ret;
- ret = hist_init(&h, 0, 0);
- cr_assert_eq(ret, 0);
+ Hist h(0, 0);
for (unsigned i = 0; i < ARRAY_LEN(test_data); i++)
- hist_put(&h, test_data[i]);
+ h.put(test_data[i]);
- cr_assert_float_eq(hist_mean(&h), 5.5, 1e-6);
- cr_assert_float_eq(hist_var(&h), 9.1666, 1e-3,);
- cr_assert_float_eq(hist_stddev(&h), 3.027650, 1e-6);
-
- hist_destroy(&h);
+ cr_assert_float_eq(h.getMean(), 5.5, 1e-6);
+ cr_assert_float_eq(h.getVar(), 9.1666, 1e-3,);
+ cr_assert_float_eq(h.getStddev(), 3.027650, 1e-6);
}