--- ray/src/util/rmatrix.c	2023/12/05 21:13:38	2.71
+++ ray/src/util/rmatrix.c	2023/12/12 18:45:53	2.76
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rmatrix.c,v 2.71 2023/12/05 21:13:38 greg Exp $";
+static const char RCSid[] = "$Id: rmatrix.c,v 2.76 2023/12/12 18:45:53 greg Exp $";
 #endif
 /*
  * General matrix operations.
@@ -450,7 +450,7 @@ rmx_write_ascii(const double *dp, int nc, int len, FIL
 {
 	while (len-- > 0) {
 		int	k = nc;
-		while (nc-- > 0)
+		while (k-- > 0)
 			fprintf(fp, " %.7e", *dp++);
 		fputc('\t', fp);
 	}
@@ -539,7 +539,9 @@ rmx_write_header(const RMATRIX *rm, int dtype, FILE *f
 		dtype = DTxyze;
 	else if ((dtype == DTxyze) & (rm->dtype == DTrgbe))
 		dtype = DTrgbe;
-	if ((dtype == DTspec) & (rm->ncomp < 3))
+	if ((dtype < DTspec) & (rm->ncomp > 3))
+		dtype = DTspec;
+	else if ((dtype == DTspec) & (rm->ncomp <= 3))
 		return(0);
 
 	if (dtype == DTascii)			/* set file type (WINDOWS) */
@@ -560,8 +562,8 @@ rmx_write_header(const RMATRIX *rm, int dtype, FILE *f
 	}
 	if (dtype >= DTspec) {			/* # components & split? */
 		fputncomp(rm->ncomp, fp);
-		if (dtype == DTspec || (rm->ncomp > 3 &&
-				memcmp(rm->wlpart, WLPART, sizeof(WLPART))))
+		if (rm->ncomp > 3 &&
+				memcmp(rm->wlpart, WLPART, sizeof(WLPART)))
 			fputwlsplit(rm->wlpart, fp);
 	} else if ((rm->ncomp != 3) & (rm->ncomp != 1))
 		return(0);			/* wrong # components */
@@ -666,6 +668,34 @@ rmx_copy(const RMATRIX *rm)
 	copycolor(dnew->cexp, rm->cexp);
 	memcpy(dnew->wlpart, rm->wlpart, sizeof(dnew->wlpart));
 	return(dnew);
+}
+
+/* Replace data in first matrix with data from second */
+int
+rmx_transfer_data(RMATRIX *rdst, RMATRIX *rsrc, int dometa)
+{
+	if (!rdst | !rsrc || (rdst->nrows != rsrc->nrows) |
+			(rdst->ncols != rsrc->ncols) |
+			(rdst->ncomp != rsrc->ncomp))
+		return(0);
+
+	if (dometa) {		/* transfer everything? */
+		rmx_reset(rdst);
+		*rdst = *rsrc;
+		rsrc->info = NULL; rsrc->mapped = NULL; rsrc->mtx = NULL;
+		return(1);
+	}
+#ifdef MAP_FILE			/* just matrix data -- leave metadata */
+	if (rdst->mapped)
+		munmap(rdst->mapped, mapped_size(rdst));
+	else
+#endif
+	if (rdst->mtx)
+		free(rdst->mtx);
+	rdst->mapped = rsrc->mapped;
+	rdst->mtx = rsrc->mtx;
+	rsrc->mapped = NULL; rsrc->mtx = NULL;
+	return(1);
 }
 
 /* Allocate and assign transposed matrix */