diff --git a/ChangeLog b/ChangeLog
index b5a2ee69..d2471435 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -17,6 +17,7 @@
 - added vips_webpload(), vips_webpload_buffer(), vips_webpsave(),
   vips_webpsave_buffer(), vips_webpsave_mime()
 - tiff reader allows separate planes for strip read
+- added vips_image_new_matrixv()
 
 3/7/13 started 7.34.2
 - lower priority for Matlab load to reduce segvs from Mat_Open(), thanks
diff --git a/TODO b/TODO
index 967f3d31..9ce423c1 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,7 @@
 - finish hist_ismonotonic()
 
+	needs im_conv()
+
 - need to do im_profile() before we can finish hist_percent()
 
 - try:
diff --git a/libvips/histogram/hist_ismonotonic.c b/libvips/histogram/hist_ismonotonic.c
index 2b7c0b1a..5ef2170d 100644
--- a/libvips/histogram/hist_ismonotonic.c
+++ b/libvips/histogram/hist_ismonotonic.c
@@ -63,11 +63,13 @@ typedef struct _VipsHistIsmonotonic {
 
 typedef VipsOperationClass VipsHistIsmonotonicClass;
 
-G_DEFINE_TYPE( VipsHistIsmonotonic, vips_hist_ismonotonic, VIPS_TYPE_OPERATION );
+G_DEFINE_TYPE( VipsHistIsmonotonic, vips_hist_ismonotonic, 
+	VIPS_TYPE_OPERATION );
 
 static int
 vips_hist_ismonotonic_build( VipsObject *object )
 {
+	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
 	VipsHistIsmonotonic *ismonotonic = (VipsHistIsmonotonic *) object; 
 	VipsImage **t = (VipsImage **) vips_object_local_array( object, 4 );
 
@@ -75,17 +77,14 @@ vips_hist_ismonotonic_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
-	if( im_check_hist( "im_ismonotonic", lut ) ||
-		im_open_local_array( lut, t, 2, "im_ismonotonic", "p" ) )
+	if( vips_check_hist( class->nickname, ismonotonic->in ) )
 		return( -1 );
 
-	if( lut->Xsize == 1 ) 
-		mask = im_create_imaskv( "im_ismonotonic", 1, 2, -1, 1 );
+	if( ismonotonic->in->Xsize == 1 ) 
+		t[0] = vips_image_new_matrixv( 1, 2, -1, 1 );
 	else 
-		mask = im_create_imaskv( "im_ismonotonic", 2, 1, -1, 1 );
-	if( !(mask = im_local_imask( lut, mask )) )
-		return( -1 );
-	mask->offset = 128;
+		t[0] = vips_image_new_matrixv( 2, 1, -1, 1 );
+        vips_image_set_double( t[0], "offset", 128 );
 
 	/* We want >=128 everywhere, ie. no -ve transitions.
 	 */
@@ -133,13 +132,12 @@ vips_hist_ismonotonic_init( VipsHistIsmonotonic *ismonotonic )
 }
 
 /**
- * im_ismonotonic:
- * @lut: lookup-table to test
- * @out: set non-zero if @lut is monotonic 
+ * vips_ismonotonic:
+ * @in: lookup-table to test
+ * @out: set non-zero if @in is monotonic 
+ * @...: %NULL-terminated list of optional named arguments
  *
- * Test @lut for monotonicity. @out is set non-zero if @lut is monotonic.
- *
- * See also: im_tone_build_range().
+ * Test @in for monotonicity. @out is set non-zero if @in is monotonic.
  *
  * Returns: 0 on success, -1 on error
  */
diff --git a/libvips/include/vips/image.h b/libvips/include/vips/image.h
index 5ee84c65..83b06185 100644
--- a/libvips/include/vips/image.h
+++ b/libvips/include/vips/image.h
@@ -519,7 +519,8 @@ VipsImage *vips_image_new_from_file_raw( const char *filename,
 	int xsize, int ysize, int bands, guint64 offset );
 VipsImage *vips_image_new_from_memory( void *buffer, 
 	int xsize, int ysize, int bands, VipsBandFormat bandfmt );
-VipsImage *vips_image_new_matrix( int xsize, int ysize );
+VipsImage *vips_image_new_matrix( int width, int height );
+VipsImage *vips_image_new_matrixv( int width, int height, ... );
 void vips_image_set_delete_on_close( VipsImage *image, 
 	gboolean delete_on_close );
 VipsImage *vips_image_new_temp_file( const char *format );
diff --git a/libvips/iofuncs/image.c b/libvips/iofuncs/image.c
index 20caa021..6c84e91b 100644
--- a/libvips/iofuncs/image.c
+++ b/libvips/iofuncs/image.c
@@ -1637,18 +1637,22 @@ vips_image_new_from_memory( void *buffer,
 
 /**
  * vips_image_new_matrix:
- * @xsize: image width
- * @ysize: image height
+ * @width: image width
+ * @height: image height
  *
  * This convenience function makes an image which is a matrix: a one-band
  * VIPS_FORMAT_DOUBLE image held in memory.
  *
  * Use VIPS_IMAGE_ADDR(), or VIPS_MATRIX() to address pixels in the image.
+ *
+ * Use vips_image_set_double() to set "scale" and "offset", if required. 
+ *
+ * See also: vips_image_new_matrixv()
  * 
  * Returns: the new #VipsImage, or %NULL on error.
  */
 VipsImage *
-vips_image_new_matrix( int xsize, int ysize )
+vips_image_new_matrix( int width, int height )
 {
 	VipsImage *image;
 
@@ -1658,8 +1662,8 @@ vips_image_new_matrix( int xsize, int ysize )
 	g_object_set( image,
 		"filename", "vips_image_new_matrix",
 		"mode", "t",
-		"width", xsize,
-		"height", ysize,
+		"width", width,
+		"height", height,
 		"bands", 1,
 		"format", VIPS_FORMAT_DOUBLE,
 		"interpretation", VIPS_INTERPRETATION_MATRIX,
@@ -1677,6 +1681,40 @@ vips_image_new_matrix( int xsize, int ysize )
 	return( image );
 }
 
+/**
+ * vips_image_new_matrixv:
+ * @width: image width
+ * @height: image height
+ * @...: matrix coefficients
+ *
+ * As vips_image_new_matrix(), but initialise the matrix from the argument
+ * list. After @height should be @width * @height double constants which are
+ * used to set the matrix elements. 
+ *
+ * See also: vips_image_new_matrix()
+ * 
+ * Returns: the new #VipsImage, or %NULL on error.
+ */
+VipsImage *
+vips_image_new_matrixv( int width, int height, ... )
+{
+	va_list ap;
+	VipsImage *matrix;
+	int x, y;
+
+	vips_check_init();
+
+	matrix = vips_image_new_matrix( width, height ); 
+
+	va_start( ap, height );
+	for( y = 0; y < height; y++ )
+		for( x = 0; x < width; x++ )
+			*VIPS_MATRIX( matrix, x, y ) = va_arg( ap, double );
+	va_end( ap );
+
+	return( matrix ); 
+}
+
 /**
  * vips_image_set_delete_on_close:
  * @image: image to set