More PG checking

3 files changed, 58 insertions, 10 deletions

diff --git a/src/symmetry.c b/src/symmetry.c
index b0e430b5..6c290756 100644
--- a/src/symmetry.c
+++ b/src/symmetry.c
@@ -405,8 +405,9 @@ static SymOpList *make_4m()
 static SymOpList *make_4()
 {
 	SymOpList *new = new_symoplist();
-	add_symop(new, v(0,1,0,0), v(1,0,0,0), v(0,0,0,1), 4); /* 4 */
-	return NULL;
+	add_symop(new, v(0,-1,0,0), v(1,0,0,0), v(0,0,0,1), 4); /* 4 */
+	new->name = strdup("4");
+	return expand_ops(new);
 }
 
 
@@ -673,6 +674,28 @@ void get_asymm(const SymOpList *ops,
 }
 
 
+static int is_inversion(const struct sym_op *op)
+{
+	if ( (op->h[0]!=-1) || (op->h[1]!=0) || (op->h[2]!=0) ) return 0;
+	if ( (op->k[0]!=0) || (op->k[1]!=-1) || (op->k[2]!=0) ) return 0;
+	if ( (op->l[0]!=0) || (op->l[1]!=0) || (op->l[2]!=-1) ) return 0;
+	return 1;
+}
+
+
+int is_centrosymmetric(const SymOpList *s)
+{
+	int i, n;
+
+	n = num_ops(s);
+	for ( i=0; i<n; i++ ) {
+		if ( is_inversion(&s->ops[i]) ) return 1;
+	}
+
+	return 0;
+}
+
+
 /**
  * get_twins:
  *
diff --git a/src/symmetry.h b/src/symmetry.h
index 45ffe318..4ecf11a4 100644
--- a/src/symmetry.h
+++ b/src/symmetry.h
@@ -48,6 +48,7 @@ extern void get_equiv(const SymOpList *ops, const SymOpMask *m, int idx,
                       signed int h, signed int k, signed int l,
                       signed int *he, signed int *ke, signed int *le);
 
+extern int is_centrosymmetric(const SymOpList *s);
 extern SymOpList *get_twins(const SymOpList *source, const SymOpList *target);
 
 #endif	/* SYMMETRY_H */
diff --git a/tests/symmetry_check.c b/tests/symmetry_check.c
index bda6961e..b3d4cb34 100644
--- a/tests/symmetry_check.c
+++ b/tests/symmetry_check.c
@@ -22,10 +22,20 @@
 #include "../src/utils.h"
 
 
-static void check_nequiv(const char *pg, int answer, int *fail)
+static const char *maybenot(int v)
+{
+	if ( v ) {
+		return "";
+	} else {
+		return " not";
+	}
+}
+
+
+static void check_pg_props(const char *pg, int answer, int centro, int *fail)
 {
 	SymOpList *sym;
-	int n;
+	int n, c;
 
 	//STATUS("**************************************** Testing '%s'\n", pg);
 
@@ -33,11 +43,18 @@ static void check_nequiv(const char *pg, int answer, int *fail)
 	n = num_equivs(sym, NULL);
 
 	if ( n != answer ) {
-		ERROR("Number of equivalents in '%s' is %i (not %i)\n",
+		ERROR("Number of equivalents in '%s' is %i (not %i).\n",
 		      pg, n, answer);
 		*fail = 1;
 	}
 
+	c = is_centrosymmetric(sym);
+	if ( c != centro ) {
+		ERROR("'%s' should%s be centrosymmetric, but is%s.\n",
+		      pg, maybenot(centro), maybenot(c));
+		*fail = 1;
+	}
+
 	free_symoplist(sym);
 }
 
@@ -46,11 +63,18 @@ int main(int argc, char *argv[])
 {
 	int fail = 0;
 
-	check_nequiv(  "1",  1, &fail);
-	check_nequiv( "-1",  2, &fail);
-	check_nequiv(  "2",  2, &fail);
-	check_nequiv(  "m",  2, &fail);
-	check_nequiv("2/m",  4, &fail);
+	check_pg_props(  "1",  1, 0, &fail);
+	check_pg_props( "-1",  2, 1, &fail);
+
+	check_pg_props(  "2",  2, 0, &fail);
+	check_pg_props(  "m",  2, 0, &fail);
+	check_pg_props("2/m",  4, 1, &fail);
+
+	check_pg_props("222",  4, 0, &fail);
+	check_pg_props("mm2",  4, 0, &fail);
+	check_pg_props("mmm",  8, 1, &fail);
+
+	check_pg_props(  "4",  4, 0, &fail);
 
 	return fail;
 }