--- ray/src/util/rmtxop.c	2019/08/12 02:26:46	2.14
+++ ray/src/util/rmtxop.c	2021/01/19 23:32:00	2.18
@@ -1,11 +1,10 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rmtxop.c,v 2.14 2019/08/12 02:26:46 greg Exp $";
+static const char RCSid[] = "$Id: rmtxop.c,v 2.18 2021/01/19 23:32:00 greg Exp $";
 #endif
 /*
  * General component matrix operations.
  */
 
-#include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include "rtio.h"
@@ -15,8 +14,6 @@ static const char RCSid[] = "$Id: rmtxop.c,v 2.14 2019
 
 #define MAXCOMP		16		/* #components we support */
 
-static const char	stdin_name[] = "<stdin>";
-
 /* unary matrix operation(s) */
 typedef struct {
 	double		sca[MAXCOMP];		/* scalar coefficients */
@@ -29,6 +26,7 @@ typedef struct {
 /* matrix input source and requested operation(s) */
 typedef struct {
 	const char	*inspec;		/* input specification */
+	RMPref		rmp;			/* matrix preference */
 	RUNARYOP	preop;			/* unary operation(s) */
 	RMATRIX		*mtx;			/* original matrix if loaded */
 	int		binop;			/* binary op with next (or 0) */
@@ -43,8 +41,7 @@ loadmatrix(ROPMAT *rop)
 	if (rop->mtx != NULL)
 		return(0);
 
-	rop->mtx = rmx_load(rop->inspec == stdin_name ?
-				(const char *)NULL : rop->inspec);
+	rop->mtx = rmx_load(rop->inspec, rop->rmp);
 	if (rop->mtx == NULL) {
 		fputs(rop->inspec, stderr);
 		fputs(": cannot load matrix\n", stderr);
@@ -140,19 +137,22 @@ binaryop(const char *inspec, RMATRIX *mleft, int op, R
 
 	if ((mleft == NULL) | (mright == NULL))
 		return(NULL);
-
 	switch (op) {
 	case '.':			/* concatenate */
-		mres = rmx_multiply(mleft, mright);
+		if (mleft->ncomp != mright->ncomp) {
+			fputs(inspec, stderr);
+			fputs(": # components do not match\n", stderr);
+		} else if (mleft->ncols != mright->nrows) {
+			fputs(inspec, stderr);
+			fputs(": mismatched dimensions\n",
+					stderr);
+		} else
+			mres = rmx_multiply(mleft, mright);
 		rmx_free(mleft);
 		rmx_free(mright);
 		if (mres == NULL) {
 			fputs(inspec, stderr);
-			if (mleft->ncols != mright->nrows)
-				fputs(": mismatched dimensions for multiply\n",
-						stderr);
-			else
-				fputs(": concatenation failed\n", stderr);
+			fputs(": concatenation failed\n", stderr);
 			return(NULL);
 		}
 		if (verbose) {
@@ -320,13 +320,13 @@ main(int argc, char *argv[])
 	for (i = 1; i < argc; i++) {
 		if (argv[i][0] && !argv[i][1] &&
 				strchr(".+*/", argv[i][0]) != NULL) {
-			if (mop[nmats].inspec == NULL || mop[nmats].binop) {
+			if (!nmats || mop[nmats-1].binop) {
 				fprintf(stderr,
-			"%s: missing matrix argument for '%c' operation\n",
+			"%s: missing matrix argument before '%c' operation\n",
 						argv[0], argv[i][0]);
 				return(1);
 			}
-			mop[nmats++].binop = argv[i][0];
+			mop[nmats-1].binop = argv[i][0];
 		} else if (argv[i][0] != '-' || !argv[i][1]) {
 			if (argv[i][0] == '-') {
 				if (stdin_used++) {
@@ -380,6 +380,14 @@ main(int argc, char *argv[])
 					get_factors(mop[nmats].preop.cmat,
 							n, argv+i+1);
 				break;
+			case 'r':
+				if (argv[i][2] == 'f')
+					mop[nmats].rmp = RMPreflF;
+				else if (argv[i][2] == 'b')
+					mop[nmats].rmp = RMPreflB;
+				else
+					goto userr;
+				break;
 			default:
 				fprintf(stderr, "%s: unknown operation '%s'\n",
 						argv[0], argv[i]);
@@ -391,6 +399,12 @@ main(int argc, char *argv[])
 	}
 	if (mop[0].inspec == NULL)	/* nothing to do? */
 		goto userr;
+	if (mop[nmats-1].binop) {
+		fprintf(stderr,
+			"%s: missing matrix argument after '%c' operation\n",
+				argv[0], mop[nmats-1].binop);
+		return(1);
+	}
 					/* favor quicker concatenation */
 	mop[nmats].mtx = prefer_right2left(mop) ? op_right2left(mop)
 						: op_left2right(mop);
@@ -416,7 +430,7 @@ main(int argc, char *argv[])
 	return(0);
 userr:
 	fprintf(stderr,
-	"Usage: %s [-v][-f[adfc][-t][-s sf .. | -c ce ..] m1 [.+*/] .. > mres\n",
+	"Usage: %s [-v][-f[adfc][-t][-s sf .. | -c ce ..][-r[fb]] m1 [.+*/] .. > mres\n",
 			argv[0]);
 	return(1);
 }