check_hkl: Move "single-list" FoMs into API

Reasons for differences:

1. Resolution shells slightly different
The binning calculation needs to take into account small rounding errors
in the resolution calculation, when not using an explicit resolution
range (--highres).  The old version did this by taking a min/max
resolution range slightly larger than the resolution of the data.  The
new version handles the rounding errors explicitly, so does not need
this.

2. Number of reflections with infinite/invalid I/sigI values halved
The number reported for this count was twice what it should have been,
due to a bug in the old check_hkl.

3. Overall SNR is different
When the above warning message applies, the old version still allowed
the reflections with invalid I/sigI values to contribute to the
denominator of the mean SNR calculation.  The new version does not
include them in the SNR calculation at all.  Note that the reflections
contribute to the other figures of merit unless otherwise stated.

4. Standard deviation of intensity is not calculated
It would've been a lot of work to include this in the new version, and
it's a totally useless number.  If you disagree, please get in touch!

2 files changed, 158 insertions, 344 deletions

diff --git a/src/check_hkl.c b/src/check_hkl.c
index f743d575..d95fc51f 100644
--- a/src/check_hkl.c
+++ b/src/check_hkl.c
@@ -45,6 +45,7 @@
 #include <reflist.h>
 #include <reflist-utils.h>
 #include <cell-utils.h>
+#include <fom.h>
 
 #include "version.h"
 
@@ -390,67 +391,16 @@ static void plot_shells(RefList *list, UnitCell *cell, const SymOpList *sym,
                         double rmin_fix, double rmax_fix, int nshells,
 			const char *shell_file)
 {
-	unsigned long *possible;
-	unsigned long *measurements;
-	unsigned long *measured;
-	unsigned long *snr_measured;
-	double total_vol, vol_per_shell;
-	double *rmins;
-	double *rmaxs;
-	double *snr;
-	double *mean;
-	double *var;
 	double rmin, rmax;
-	signed int h, k, l;
 	int i;
 	FILE *fh;
-	double snr_total = 0;
-	unsigned long nrefl = 0;
-	unsigned long nmeastot = 0;
-	unsigned long nout = 0;
-	unsigned long possible_tot = 0;
-	unsigned long nsilly = 0;
-	Reflection *refl;
-	RefListIterator *iter;
-	RefList *counted;
-	int hmax, kmax, lmax;
-	double ax, ay, az;
-	double bx, by, bz;
-	double cx, cy, cz;
-
-	possible = malloc(nshells*sizeof(unsigned long));
-	measurements = malloc(nshells*sizeof(unsigned long));
-	measured = malloc(nshells*sizeof(unsigned long));
-	snr_measured = malloc(nshells*sizeof(unsigned long));
-	if ( (possible == NULL) || (measurements == NULL)
-	  || (measured == NULL) || (snr_measured == NULL) ) {
-		ERROR("Couldn't allocate memory.\n");
-		free(possible);
-		free(measurements);
-		free(measured);
-		free(snr_measured);
-		return;
-	}
-
-	rmins = malloc(nshells*sizeof(double));
-	rmaxs = malloc(nshells*sizeof(double));
-	snr = malloc(nshells*sizeof(double));
-	mean = malloc(nshells*sizeof(double));
-	var = malloc(nshells*sizeof(double));
-	if ( (rmins == NULL) || (rmaxs == NULL) || (snr == NULL)
-	  || (mean == NULL) || (var == NULL) ) {
-		ERROR("Couldn't allocate memory.\n");
-		free(possible);
-		free(measurements);
-		free(measured);
-		free(snr_measured);
-		free(rmins);
-		free(rmaxs);
-		free(snr);
-		free(mean);
-		free(var);
-		return;
-	}
+	struct fom_shells *shells;
+	struct fom_context *nmeas_ctx;
+	struct fom_context *red_ctx;
+	struct fom_context *snr_ctx;
+	struct fom_context *mean_ctx;
+	struct fom_context *stddev_ctx;
+	struct fom_context *compl_ctx;
 
 	fh = fopen(shell_file, "w");
 	if ( fh == NULL ) {
@@ -458,224 +408,72 @@ static void plot_shells(RefList *list, UnitCell *cell, const SymOpList *sym,
 		return;
 	}
 
-	for ( i=0; i<nshells; i++ ) {
-		possible[i] = 0;
-		measured[i] = 0;
-		snr_measured[i] = 0;
-		measurements[i] = 0;
-		snr[i] = 0;
-		var[i] = 0;
-		mean[i] = 0;
-	}
-
 	resolution_limits(list, cell, &rmin, &rmax);
 	STATUS("1/d goes from %f to %f nm^-1\n", rmin/1e9, rmax/1e9);
 
-	/* Widen the range just a little bit */
-	rmin -= 0.001e9;
-	rmax += 0.001e9;
-
 	/* Fixed resolution shells if needed */
 	if ( rmin_fix > 0.0 ) rmin = rmin_fix;
 	if ( rmax_fix > 0.0 ) rmax = rmax_fix;
 
-	total_vol = pow(rmax, 3.0) - pow(rmin, 3.0);
-	vol_per_shell = total_vol / nshells;
-	rmins[0] = rmin;
-	for ( i=1; i<nshells; i++ ) {
-
-		double r;
-
-		r = vol_per_shell + pow(rmins[i-1], 3.0);
-		r = pow(r, 1.0/3.0);
-
-		/* Shells of constant volume */
-		rmaxs[i-1] = r;
-		rmins[i] = r;
-	}
-	rmaxs[nshells-1] = rmax;
-
-	/* Count the number of reflections possible in each shell */
-	counted = reflist_new();
-	cell_get_cartesian(cell, &ax, &ay, &az,
-	                         &bx, &by, &bz,
-	                         &cx, &cy, &cz);
-	hmax = rmax * modulus(ax, ay, az);
-	kmax = rmax * modulus(bx, by, bz);
-	lmax = rmax * modulus(cx, cy, cz);
-	for ( h=-hmax; h<=hmax; h++ ) {
-	for ( k=-kmax; k<=kmax; k++ ) {
-	for ( l=-lmax; l<=lmax; l++ ) {
-
-		double d;
-		signed int hs, ks, ls;
-		int bin;
-
-		get_asymm(sym, h, k, l, &hs, &ks, &ls);
-		d = 2.0 * resolution(cell, hs, ks, ls);
-
-		if ( forbidden_reflection(cell, h, k, l) ) continue;
-
-		bin = -1;
-		for ( i=0; i<nshells; i++ ) {
-			if ( (d>rmins[i]) && (d<=rmaxs[i]) ) {
-				bin = i;
-				break;
-			}
-		}
-		if ( bin == -1 ) continue;
-
-		if ( find_refl(counted, hs, ks, ls) != NULL ) continue;
-		add_refl(counted, hs, ks, ls);
-
-		possible[bin]++;
-		possible_tot++;
-
-	}
-	}
-	}
-	reflist_free(counted);
-
-	/* Calculate means */
-	for ( refl = first_refl(list, &iter);
-	      refl != NULL;
-	      refl = next_refl(refl, iter) )
-	{
-		signed int h, k, l, hs, ks, ls;
-		double d, val, esd;
-		int bin;
-		int j;
-
-		get_indices(refl, &h, &k, &l);
-		if ( forbidden_reflection(cell, h, k, l) ) continue;
-
-		get_asymm(sym, h, k, l, &hs, &ks, &ls);
-		d = resolution(cell, hs, ks, ls) * 2.0;
-		val = get_intensity(refl);
-		esd = get_esd_intensity(refl);
-
-		bin = -1;
-		for ( j=0; j<nshells; j++ ) {
-			if ( (d>rmins[j]) && (d<=rmaxs[j]) ) {
-				bin = j;
-				break;
-			}
-		}
-		if ( bin == -1 ) continue;
-
-		measured[bin]++;
-		mean[bin] += get_intensity(refl);
-
-		if ( !isfinite(val/esd) ) nsilly++;
-
-	}
-
-	for ( i=0; i<nshells; i++ ) {
-		mean[i] /= (double)measured[i];
-	}
-
-	/* Characterise the data set */
-	for ( refl = first_refl(list, &iter);
-	      refl != NULL;
-	      refl = next_refl(refl, iter) )
-	{
-		signed int h, k, l;
-		double d;
-		int bin;
-		int j;
-		double val, esd;
-
-		get_indices(refl, &h, &k, &l);
-		if ( forbidden_reflection(cell, h, k, l) ) continue;
-
-		d = resolution(cell, h, k, l) * 2.0;
-		val = get_intensity(refl);
-		esd = get_esd_intensity(refl);
-
-		bin = -1;
-		for ( j=0; j<nshells; j++ ) {
-			if ( (d>rmins[j]) && (d<=rmaxs[j]) ) {
-				bin = j;
-				break;
-			}
-		}
-		if ( bin == -1 ) {
-			nout++;
-			continue;
-		}
-
-		/* measured[bin] was done earlier */
-		measurements[bin] += get_redundancy(refl);
-
-		if ( isfinite(val/esd) ) {
-			snr[bin] += val / esd;
-			snr_total += val / esd;
-			snr_measured[bin]++;
-		} else {
-			nsilly++;
-		}
-
-		nrefl++;
-		nmeastot += get_redundancy(refl);
-
-		var[bin] += pow(val-mean[bin], 2.0);
-
-	}
+	shells = fom_make_resolution_shells(rmin, rmax,  nshells);
 
 	STATUS("Overall values within specified resolution range:\n");
-	STATUS("%li measurements in total.\n", nmeastot);
-	STATUS("%li reflections in total.\n", nrefl);
-	STATUS("%li reflections possible.\n", possible_tot);
-	STATUS("Overall <snr> = %f\n", snr_total/(double)nrefl);
-	STATUS("Overall redundancy = %f measurements/unique reflection\n",
-	       nmeastot/(double)nrefl);
-	STATUS("Overall completeness = %f %%\n", 100.0*nrefl/(double)possible_tot);
 
-	if ( nout ) {
-		STATUS("WARNING; %li reflections outside resolution range.\n",
-		       nout);
-	}
-
-	if ( nsilly ) {
-		STATUS("WARNING; %li reflections had infinite or invalid values"
-		       " of I/sigma(I).\n", nsilly);
-	}
+	nmeas_ctx = fom_calculate(list, NULL, cell, shells,
+	                          FOM_NUM_MEASUREMENTS, 0, sym);
+	red_ctx = fom_calculate(list, NULL, cell, shells,
+	                        FOM_REDUNDANCY, 0, sym);
+	snr_ctx = fom_calculate(list, NULL, cell, shells,
+	                        FOM_SNR, 0, sym);
+	mean_ctx = fom_calculate(list, NULL, cell, shells,
+	                         FOM_MEAN_INTENSITY, 0, sym);
+	stddev_ctx = fom_calculate(list, NULL, cell, shells,
+	                           FOM_STDDEV_INTENSITY, 0, sym);
+	compl_ctx = fom_calculate(list, NULL, cell, shells,
+	                          FOM_COMPLETENESS, 0, sym);
+
+	STATUS("%.0f measurements in total.\n",
+	       fom_overall_value(nmeas_ctx));
+	STATUS("%li reflections in total.\n",
+	       fom_overall_num_reflections(compl_ctx));
+	STATUS("%li reflections possible.\n",
+	       fom_overall_num_possible(compl_ctx));
+	STATUS("Overall <snr> = %f\n", fom_overall_value(snr_ctx));
+	STATUS("Overall redundancy = %f measurements/unique reflection\n",
+	       fom_overall_value(red_ctx));
+	STATUS("Overall completeness = %f %%\n",
+	       100.0*fom_overall_value(compl_ctx));
 
 	fprintf(fh, "Center 1/nm  # refs Possible  Compl       "
 		    "Meas   Red   SNR    Std dev       Mean     d(A)    "
 		    "Min 1/nm   Max 1/nm\n");
 	for ( i=0; i<nshells; i++ ) {
 
-		double cen;
-		cen = rmins[i] + (rmaxs[i] - rmins[i])/2.0;
-		fprintf(fh, "%10.3f %8li %8li %6.2f %10li %5.1f"
+		long int measured, possible;
+
+		measured = fom_shell_num_reflections(compl_ctx, i);
+		possible = fom_shell_num_possible(compl_ctx, i);
+
+		fprintf(fh, "%10.3f %8li %8li %6.2f %10.0f %5.1f"
 		            " %5.2f %10.2f %10.2f %8.2f  %10.3f %10.3f\n",
-		        cen*1.0e-9,
-		        measured[i],
-		        possible[i],
-		        100.0*(double)measured[i]/possible[i],
-		        measurements[i],
-		        (double)measurements[i]/measured[i],
-		        snr[i]/(double)snr_measured[i],
-		        sqrt(var[i]/measured[i]),
-		        mean[i], (1.0/cen)*1e10,
-			rmins[i]*1.0e-9, rmaxs[i]*1.0e-9);
+		        fom_shell_centre(shells, i)*1.0e-9,
+		        measured,
+		        possible,
+		        100.0*fom_shell_value(compl_ctx, i),
+		        fom_shell_value(nmeas_ctx, i),
+		        fom_shell_value(red_ctx, i),
+		        fom_shell_value(snr_ctx, i),
+		        fom_shell_value(stddev_ctx, i),
+		        fom_shell_value(mean_ctx, i),
+		        (1.0/fom_shell_centre(shells, i))*1e10,
+			shells->rmins[i]*1.0e-9,
+			shells->rmaxs[i]*1.0e-9);
 
 	}
 
 	fclose(fh);
 
 	STATUS("Resolution shell information written to %s.\n", shell_file);
-
-	free(possible);
-	free(measurements);
-	free(measured);
-	free(snr_measured);
-	free(rmins);
-	free(rmaxs);
-	free(snr);
-	free(mean);
-	free(var);
 }
 
 
@@ -711,10 +509,7 @@ int main(int argc, char *argv[])
 	SymOpList *sym;
 	RefList *raw_list;
 	RefList *list;
-	Reflection *refl;
-	RefListIterator *iter;
 	char *cellfile = NULL;
-	int rej = 0;
 	float rmin_fix = -1.0;
 	float rmax_fix = -1.0;
 	float sigma_cutoff = -INFINITY;
@@ -725,9 +520,8 @@ int main(int argc, char *argv[])
 	int ltest = 0;
 	int ignorenegs = 0;
 	int zeronegs = 0;
-	int nneg = 0;
-	int nres = 0;
 	float highres, lowres;
+	struct fom_rejections rej;
 
 	/* Long options */
 	const struct option longopts[] = {
@@ -905,74 +699,32 @@ int main(int argc, char *argv[])
 	}
 
 	/* Reject some reflections */
-	list = reflist_new();
-	for ( refl = first_refl(raw_list, &iter);
-	      refl != NULL;
-	      refl = next_refl(refl, iter) ) {
-
-		signed int h, k, l;
-		double val, sig;
-		int ig = 0;
-		Reflection *new;
-
-		get_indices(refl, &h, &k, &l);
+	rej = fom_select_reflections(raw_list, &list, cell, sym,
+	                             rmin_fix, rmax_fix, sigma_cutoff,
+	                             ignorenegs, zeronegs, 0);
 
-		val = get_intensity(refl);
-		sig = get_esd_intensity(refl);
-
-		if ( val < sigma_cutoff * sig ) {
-			rej++;
-			ig = 1;
-		}
-
-		if ( ignorenegs && (val < 0.0) ) {
-			nneg++;
-			ig = 1;
-		}
-
-		if ( zeronegs && (val < 0.0) ) {
-			set_intensity(refl, 0.0);
-			nneg++;
-		}
-
-		if ( rmin_fix > 0.0 ) {
-			double res = 2.0*resolution(cell, h, k, l);
-			if ( res < rmin_fix ) {
-				nres++;
-				continue;
-			}
-		}
-
-		if ( rmax_fix > 0.0 ) {
-			double res = 2.0*resolution(cell, h, k, l);
-			if ( res > rmax_fix ) {
-				nres++;
-				continue;
-			}
-		}
-
-		if ( ig ) continue;
-
-		new = add_refl(list, h, k, l);
-		copy_data(new, refl);
-
-	}
 	STATUS("Discarded %i reflections (out of %i) with I/sigma(I) < %f\n",
-	       rej, num_reflections(raw_list), sigma_cutoff);
+	       rej.low_snr, num_reflections(raw_list), sigma_cutoff);
 	reflist_free(raw_list);
 
-	if ( ignorenegs && (nneg > 0) ) {
+	if ( rej.negative_deleted > 0 ) {
 		STATUS("Discarded %i reflections because they had negative "
-		       "intensities.\n", nneg);
+		       "intensities.\n", rej.negative_deleted);
 	}
 
-	if ( zeronegs && (nneg > 0) ) {
-		STATUS("Set %i negative intensities to zero\n", nneg);
+	if ( rej.negative_zeroed > 0 ) {
+		STATUS("Set %i negative intensities to zero\n",
+		       rej.negative_zeroed);
 	}
 
-	if ( nres > 0 ) {
+	if ( rej.outside_resolution_range > 0 ) {
 		STATUS("%i reflections rejected because they were outside the "
-		       "resolution range.\n", nres);
+		       "resolution range.\n", rej.outside_resolution_range);
+	}
+
+	if ( rej.nan_inf_value ) {
+		STATUS("WARNING: %i reflections had infinite or invalid values"
+		       " of I or sigma(I).\n", rej.nan_inf_value);
 	}
 
 	if ( wilson ) {
diff --git a/src/compare_hkl.c b/src/compare_hkl.c
index 2cd7207b..cb5bee38 100644
--- a/src/compare_hkl.c
+++ b/src/compare_hkl.c
@@ -106,55 +106,58 @@ static void do_fom(RefList *list1, RefList *list2, UnitCell *cell,
 	switch ( fom ) {
 
 		case FOM_R1I :
-		STATUS("Overall R1(I) = %.2f %%\n", 100.0*fom_overall(fctx));
+		STATUS("Overall R1(I) = %.2f %%\n", 100.0*fom_overall_value(fctx));
 		break;
 
 		case FOM_R1F :
-		STATUS("Overall R1(F) = %.2f %%\n", 100.0*fom_overall(fctx));
+		STATUS("Overall R1(F) = %.2f %%\n", 100.0*fom_overall_value(fctx));
 		break;
 
 		case FOM_R2 :
-		STATUS("Overall R(2) = %.2f %%\n", 100.0*fom_overall(fctx));
+		STATUS("Overall R(2) = %.2f %%\n", 100.0*fom_overall_value(fctx));
 		break;
 
 		case FOM_RSPLIT :
-		STATUS("Overall Rsplit = %.2f %%\n", 100.0*fom_overall(fctx));
+		STATUS("Overall Rsplit = %.2f %%\n", 100.0*fom_overall_value(fctx));
 		break;
 
 		case FOM_CC :
-		STATUS("Overall CC = %.7f\n", fom_overall(fctx));
+		STATUS("Overall CC = %.7f\n", fom_overall_value(fctx));
 		break;
 
 		case FOM_CCSTAR :
-		STATUS("Overall CC* = %.7f\n", fom_overall(fctx));
+		STATUS("Overall CC* = %.7f\n", fom_overall_value(fctx));
 		break;
 
 		case FOM_CCANO :
-		STATUS("Overall CCano = %.7f\n", fom_overall(fctx));
+		STATUS("Overall CCano = %.7f\n", fom_overall_value(fctx));
 		break;
 
 		case FOM_CRDANO :
-		STATUS("Overall CRDano = %.7f\n", fom_overall(fctx));
+		STATUS("Overall CRDano = %.7f\n", fom_overall_value(fctx));
 		break;
 
 		case FOM_RANO :
-		STATUS("Overall Rano =  %.2f %%\n", 100.0*fom_overall(fctx));
+		STATUS("Overall Rano =  %.2f %%\n", 100.0*fom_overall_value(fctx));
 		break;
 
 		case FOM_RANORSPLIT :
-		STATUS("Overall Rano/Rsplit =  %.7f\n", fom_overall(fctx));
+		STATUS("Overall Rano/Rsplit =  %.7f\n", fom_overall_value(fctx));
 		break;
 
 		case FOM_D1SIG :
 		STATUS("Fraction of differences less than 1 sigma = %.7f %%\n",
-		       100.0*fom_overall(fctx));
+		       100.0*fom_overall_value(fctx));
 		break;
 
 		case FOM_D2SIG :
 		STATUS("Fraction of differences less than 2 sigma = %.7f %%\n",
-		       100.0*fom_overall(fctx));
+		       100.0*fom_overall_value(fctx));
 		break;
 
+		default :
+		ERROR("Unhandled figure of merit type\n");
+		break;
 
 	}
 
@@ -217,14 +220,17 @@ static void do_fom(RefList *list1, RefList *list2, UnitCell *cell,
 		fprintf(fh, "%s D<2sigma/%%     nref%s\n", t1, t2);
 		break;
 
+		default :
+		break;
+
 	}
 
 	for ( i=0; i<nshells; i++ ) {
 
 		double r, cen;
 
-		cen = fom_shell_label(shells, i);
-		r = fom_shell(fctx, i);
+		cen = fom_shell_centre(shells, i);
+		r = fom_shell_value(fctx, i);
 
 		switch ( fom ) {
 
@@ -235,7 +241,8 @@ static void do_fom(RefList *list1, RefList *list2, UnitCell *cell,
 			case FOM_RANO :
 			fprintf(fh, "%10.3f %10.2f %10i %10.2f "
 			        "%10.3f  %10.3f\n",
-			        cen*1.0e-9, r*100.0, fctx->cts[i],
+			        cen*1.0e-9, r*100.0,
+			        fom_shell_num_reflections(fctx, i),
 			        (1.0/cen)*1e10,
 			        shells->rmins[i]*1.0e-9,
 			        shells->rmaxs[i]*1.0e-9);
@@ -247,7 +254,9 @@ static void do_fom(RefList *list1, RefList *list2, UnitCell *cell,
 			case FOM_CRDANO :
 			fprintf(fh, "%10.3f %10.7f %10i %10.2f "
 			        "%10.3f  %10.3f\n",
-			        cen*1.0e-9, r, fctx->cts[i], (1.0/cen)*1e10,
+			        cen*1.0e-9, r,
+			        fom_shell_num_reflections(fctx, i),
+			        (1.0/cen)*1e10,
 			        shells->rmins[i]*1.0e-9,
 			        shells->rmaxs[i]*1.0e-9);
 			break;
@@ -255,7 +264,9 @@ static void do_fom(RefList *list1, RefList *list2, UnitCell *cell,
 			case FOM_RANORSPLIT :
 			fprintf(fh, "%10.3f    %10.7f %10i %10.2f "
 			        "%10.3f  %10.3f\n",
-			        cen*1.0e-9, r, fctx->cts[i], (1.0/cen)*1e10,
+			        cen*1.0e-9, r,
+			        fom_shell_num_reflections(fctx, i),
+			        (1.0/cen)*1e10,
 			        shells->rmins[i]*1.0e-9,
 			        shells->rmaxs[i]*1.0e-9);
 			break;
@@ -264,12 +275,16 @@ static void do_fom(RefList *list1, RefList *list2, UnitCell *cell,
 			case FOM_D2SIG :
 			fprintf(fh, "%10.3f %10.2f %10i %10.2f "
 			        "%10.3f  %10.3f\n",
-			        cen*1.0e-9, r*100.0, fctx->cts[i],
+			        cen*1.0e-9, r*100.0,
+			        fom_shell_num_reflections(fctx, i),
 			        (1.0/cen)*1e10,
 			        shells->rmins[i]*1.0e-9,
 			        shells->rmaxs[i]*1.0e-9);
 			break;
 
+			default :
+			break;
+
 		}
 
 	}
@@ -311,7 +326,6 @@ int main(int argc, char *argv[])
 	char *sym_str_fromfile1 = NULL;
 	char *sym_str_fromfile2 = NULL;
 	SymOpList *sym;
-	int ncom;
 	RefList *list1_acc;
 	RefList *list2_acc;
 	RefList *list1;
@@ -332,6 +346,7 @@ int main(int argc, char *argv[])
 	float highres, lowres;
 	int mul_cutoff = 0;
 	int anom;
+	struct fom_rejections rej;
 
 	/* Long options */
 	const struct option longopts[] = {
@@ -478,7 +493,7 @@ int main(int argc, char *argv[])
 			      " intensities.\n");
 			ERROR("Please try again with --ignore-negs or"
 			      " --zero-negs.\n");
-			exit(1);
+			return 1;
 
 			case FOM_R2 :
 			case FOM_R1I :
@@ -492,6 +507,10 @@ int main(int argc, char *argv[])
 			case FOM_D1SIG :
 			case FOM_D2SIG :
 			break;
+
+			default :
+			ERROR("Unhandled figure of merit!\n");
+			return 1;
 		}
 	}
 
@@ -579,6 +598,10 @@ int main(int argc, char *argv[])
 			      " try again using a non-centrosymmetric point"
 			      " group for '-y'.\n");
 			return 1;
+
+			default :
+			ERROR("Unhandled figure of merit type!\n");
+			return 1;
 		}
 	}
 
@@ -622,21 +645,60 @@ int main(int argc, char *argv[])
 	reflist_free(list1_raw);
 	reflist_free(list2_raw);
 
-	list1_acc = reflist_new();
-	list2_acc = reflist_new();
 	anom = ( (fom == FOM_CCANO) || (fom == FOM_CRDANO)
 	        || (fom == FOM_RANO) || (fom == FOM_RANORSPLIT) );
-	ncom = fom_select_reflections(list1, list2, list1_acc, list2_acc,
-	                              cell, sym,
-	                              anom, rmin_fix, rmax_fix, sigma_cutoff,
-	                              config_ignorenegs, config_zeronegs,
-	                              mul_cutoff);
+	rej = fom_select_reflection_pairs(list1, list2, &list1_acc, &list2_acc,
+	                                  cell, sym,
+	                                  anom, rmin_fix, rmax_fix, sigma_cutoff,
+	                                  config_ignorenegs, config_zeronegs,
+	                                  mul_cutoff);
 	reflist_free(list1);
 	reflist_free(list2);
 
 	gsl_set_error_handler_off();
 
-	STATUS("%i reflection pairs accepted.\n", ncom);
+	if ( rej.low_snr > 0 ) {
+		STATUS("Discarded %i reflection pairs because either or both"
+		       " versions had I/sigma(I) < %f.\n",
+		       rej.low_snr, sigma_cutoff);
+	}
+
+	if ( rej.negative_deleted > 0 ) {
+		STATUS("Discarded %i reflection pairs because either or both"
+		       " versions had negative intensities.\n",
+		       rej.negative_deleted);
+	}
+
+	if ( rej.negative_zeroed > 0 ) {
+		STATUS("For %i reflection pairs, either or both versions had"
+		       " negative intensities which were set to zero.\n",
+		       rej.negative_zeroed);
+	}
+
+	if ( rej.few_measurements > 0 ) {
+		STATUS("%i reflection pairs rejected because either or both"
+		       " versions had too few measurements.\n",
+		       rej.few_measurements);
+	}
+
+	if ( rej.outside_resolution_range > 0 ) {
+		STATUS("%i reflection pairs rejected because either or both"
+		       " versions were outside the resolution range.\n",
+		       rej.outside_resolution_range);
+	}
+
+	if ( rej.no_bijvoet > 0 ) {
+		STATUS("%i reflection pairs rejected because either or both"
+		       " versions did not have Bijvoet partners.\n",
+		       rej.no_bijvoet);
+	}
+
+	if ( rej.centric > 0 ) {
+		STATUS("%i reflection pairs rejected because they were"
+		       " centric.\n", rej.centric);
+	}
+
+	STATUS("%i reflection pairs accepted.\n", rej.common);
 
 	resolution_limits(list1_acc, cell, &rmin, &rmax);
 	resolution_limits(list2_acc, cell, &rmin, &rmax);