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-rw-r--r--libcrystfel/src/histogram.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/libcrystfel/src/histogram.c b/libcrystfel/src/histogram.c
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+/*
+ * histogram.c
+ *
+ * Quick histogram functions
+ *
+ * Copyright © 2013 Deutsches Elektronen-Synchrotron DESY,
+ * a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ * 2013 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"
+
+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);
+}
+
+
+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);
+}