Orient major axis of contour to point in negative direction.

share/lib/hoc/import3d/import3d_gui.hoc

@@ -1227,14 +1227,21 @@ proc contour2centroid() {local i, j, imax, imin, ok  localobj mean, pts, d, max,
 	tobj = m.symmeig(m)
 	// major axis is the one with largest eigenvalue
 	major = m.getcol(tobj.max_ind)
+	// For plotting and round-off error consistency
+        // want major axis to point in negative direction.
+	// i.e. greatest value is negative.
+	if (major.x[major.c.abs().max_ind()] > 0) {
+		printf("reorient major\n")
+		major.mul(-1)
+	}
 	// minor is normal and in xy plane
 	minor = m.getcol(3-tobj.min_ind-tobj.max_ind)
 	minor.x[2] = 0
 	minor.div(minor.mag)
-if (g != nil) {
-g.beginline(4, 3) g.line(mean.x[0], mean.x[1])
-g.line(mean.x[0] + 20*major.x[0], mean.x[1] + 20*major.x[1]) g.flush
-}
+	if (g != nil) {
+		g.beginline(4, 3) g.line(mean.x[0], mean.x[1])
+		g.line(mean.x[0] + 20*major.x[0], mean.x[1] + 20*major.x[1]) g.flush
+	}
 	d = new Vector(pts.ncol)
 	rad = new Vector(pts.ncol)
 	for i=0, pts.ncol-1 {
@@ -1297,7 +1304,6 @@ if (g != nil) g.line(tobj.x[0], tobj.x[1]) g.flush
 	for i=1,3 { $oi = pts.getrow(i-1) }
 //	print d  d.printf  print rad rad.printf
 //	print side2 side2.printf  print rad2  rad2.printf
-        orient($o1, $o2, $o3, $o4) // 0 end first
 }
 
 proc contourstack2centroid() {local i, j, area, d  localobj c
@@ -1310,29 +1316,6 @@ proc contourstack2centroid() {local i, j, area, d  localobj c
 		c = $o5.contour_list.object(j).approximate_contour_by_circle(&d)
 		$o4.append(d) for i=1,3 { $oi.append(c.x[i-1]) }
 	}
-        orient($o1, $o2, $o3, $o4) // 0 end first
-}
-
-proc orient() { local i, n1, r  localobj v1
-    // first point defines the 0 end. If we want that to be the 1 end,
-    // then reverse.
-    r = 0 // do not reverse
-    n1 = $o1.size() - 1
-    v1 = new Vector(3)
-    v1.x[0] = $o1.x[n1] - $o1.x[0]
-    v1.x[1] = $o2.x[n1] - $o2.x[0]
-    v1.x[2] = $o3.x[n1] - $o3.x[0]
-    // reverse if largest direction not positive
-    i = v1.c().abs().max_ind()
-    if (v1.x[i] < 0) {
-        r = 1
-    }
-    if (r) {
-        $o1.reverse()
-        $o2.reverse()
-        $o3.reverse()
-        $o4.reverse()
-    }
 }
 
 proc name() {