Move Histogram out of API

It's only used by two test programs

1 files changed, 280 insertions, 0 deletions

diff --git a/tests/histogram.c b/tests/histogram.c
new file mode 100644
index 00000000..69acd987
--- /dev/null
+++ b/tests/histogram.c
@@ -0,0 +1,280 @@
+/*
+ * histogram.c
+ *
+ * Quick histogram functions
+ *
+ * Copyright © 2013-2014 Deutsches Elektronen-Synchrotron DESY,
+ *                       a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *  2013-2014 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+#include <assert.h>
+
+#include "histogram.h"
+
+/** \file histogram.h */
+
+struct _histogram
+{
+	int n_vals;
+	int max_vals;
+	double *vals;
+
+	double min;
+	double max;
+
+	int full;
+
+	int n_bins;
+	double bin_width;
+
+	int *bins;
+
+	int plot_height;
+	int peak;
+	double mean;
+	double stddev;
+};
+
+
+Histogram *histogram_init()
+{
+	Histogram *hi;
+
+	hi = malloc(sizeof(struct _histogram));
+	if ( hi == NULL ) return NULL;
+
+	hi->n_vals = 0;
+	hi->max_vals = 0;
+	hi->vals = NULL;
+	hi->full = 0;
+
+	hi->max = -INFINITY;
+	hi->min = INFINITY;
+
+	hi->bins = NULL;
+	hi->n_bins = 50;
+
+	hi->plot_height = 10;
+
+	return hi;
+}
+
+
+void histogram_free(Histogram *hi)
+{
+	free(hi);
+}
+
+
+void histogram_add_value(Histogram *hi, double val)
+{
+	if ( hi->n_vals == hi->max_vals ) {
+		double *new_vals;
+		new_vals = realloc(hi->vals, (hi->max_vals+512)*sizeof(double));
+		if ( new_vals == NULL ) {
+			hi->full = 1;
+			fprintf(stderr, "Histogram %p full.\n", hi);
+			return;
+		}
+		hi->max_vals += 512;
+		hi->vals = new_vals;
+	}
+
+	hi->vals[hi->n_vals++] = val;
+
+	if ( val > hi->max ) hi->max = val;
+	if ( val < hi->min ) hi->min = val;
+}
+
+
+static void calc_bins(Histogram *hi)
+{
+	int i;
+
+	if ( hi->bins != NULL ) {
+		free(hi->bins);
+	}
+
+	hi->bins = calloc(hi->n_bins, sizeof(int));
+	if ( hi->bins == NULL ) {
+		fprintf(stderr, "Failed to allocate bins.\n");
+		return;
+	}
+
+	hi->bin_width = (hi->max - hi->min)/hi->n_bins;
+
+	for ( i=0; i<hi->n_vals; i++ ) {
+
+		int j;
+
+		j = (hi->vals[i] - hi->min) / hi->bin_width;
+
+		/* Tidy up rounding errors */
+		if ( j < 0 ) j = 0;
+		if ( j >= hi->n_bins ) j = hi->n_bins - 1;
+
+		hi->bins[j]++;
+
+	}
+
+	hi->peak = 0;
+	for ( i=0; i<hi->n_bins; i++ ) {
+		if ( hi->bins[i] > hi->peak ) hi->peak = hi->bins[i];
+	}
+}
+
+
+static void calc_stddev(Histogram *hi)
+{
+	double sum = 0.0;
+	int i;
+
+	for ( i=0; i<hi->n_vals; i++ ) {
+		sum += hi->vals[i];
+	}
+	hi->mean = sum / hi->n_vals;
+
+	sum = 0.0;
+	for ( i=0; i<hi->n_vals; i++ ) {
+		sum += pow(hi->vals[i] - hi->mean, 2.0);
+	}
+	hi->stddev = sqrt(sum / hi->n_vals);
+}
+
+
+int *histogram_get_data(Histogram *hi, int *n)
+{
+	calc_bins(hi);
+	*n = hi->n_bins;
+	return hi->bins;
+}
+
+
+void histogram_show(Histogram *hi)
+{
+	int i;
+	int *bins;
+	double lines_per_count;
+	char tmp[32];
+	size_t n_left, n_mid, n_right;
+
+	calc_bins(hi);
+	calc_stddev(hi);
+
+	bins = malloc(hi->n_bins*sizeof(int));
+	if ( bins == NULL ) {
+		fprintf(stderr, "Couldn't scale bins\n");
+		return;
+	}
+
+	lines_per_count = (double)hi->plot_height / hi->peak;
+
+	for ( i=0; i<hi->n_bins; i++ ) {
+		bins[i] = hi->bins[i] * lines_per_count;
+	}
+
+	for ( i=hi->plot_height-1; i>=0; i-- ) {
+
+		int j;
+
+		for ( j=0; j<hi->n_bins; j++ ) {
+			if ( bins[j] > i ) {
+				printf("*");
+			} else {
+				printf(" ");
+			}
+		}
+		printf("\n");
+
+	}
+
+	printf("|");
+	for ( i=1; i<hi->n_bins-1; i++ ) {
+		double bin_low, bin_high;
+		bin_low = hi->min + i*hi->bin_width;
+		bin_high = hi->min + (i+1)*hi->bin_width;
+		if ( (bin_low < 0.0) && (bin_high > 0.0) ) {
+			printf("+");
+		} else {
+			printf("-");
+		}
+	}
+	printf("|\n");
+
+	snprintf(tmp, 31, "%.2f", hi->min);
+	n_left = strlen(tmp);
+	snprintf(tmp, 31, "%.2f", hi->max);
+	n_right = strlen(tmp);
+	n_mid = hi->n_bins - (n_left + n_right);
+
+	printf("%.2f", hi->min);
+	for ( i=0; i<n_mid; i++ ) printf(" ");
+	printf("%.2f\n", hi->max);
+
+	printf("Mean = %.2f, Std dev = %.2f\n", hi->mean, hi->stddev);
+
+	free(bins);
+}
+
+
+double histogram_get_min(Histogram *hi)
+{
+	return hi->min;
+}
+
+
+double histogram_get_max(Histogram *hi)
+{
+	return hi->max;
+}
+
+
+int histogram_get_num_bins(Histogram *hi)
+{
+	return hi->n_bins;
+}
+
+
+void histogram_set_min(Histogram *hi, double min)
+{
+	hi->min = min;
+}
+
+
+void histogram_set_max(Histogram *hi, double max)
+{
+	hi->max = max;
+}
+
+
+void histogram_set_num_bins(Histogram *hi, int n)
+{
+	hi->n_bins = n;
+}