cairo-chart.c: new struct xrchart_axis

This allows a bit of refactoring.

diff --git a/src/output/cairo-chart.c b/src/output/cairo-chart.c
index 3ec00ce9a53920c978afcb05bc2ec598f0cf304c..070319a58ed07ae78c40c896bea092f2ff4b58e1 100644 (file)
--- a/src/output/cairo-chart.c
+++ b/src/output/cairo-chart.c
@@ -47,10 +47,10 @@ xrchart_geometry_init (cairo_t *cr, struct xrchart_geometry *geom,
                        double width, double length)
 {
   /* Set default chartetry. */
-  geom->data_top = 0.900 * length;
-  geom->data_right = 0.800 * width;
-  geom->data_bottom = 0.120 * length;
-  geom->data_left = 0.150 * width;
+  geom->axis[SCALE_ORDINATE].data_max = 0.900 * length;
+  geom->axis[SCALE_ABSCISSA].data_max = 0.800 * width;
+  geom->axis[SCALE_ORDINATE].data_min = 0.120 * length;
+  geom->axis[SCALE_ABSCISSA].data_min = 0.150 * width;
   geom->abscissa_top = 0.070 * length;
   geom->ordinate_right = 0.120 * width;
   geom->title_bottom = 0.920 * length;
@@ -67,9 +67,9 @@ xrchart_geometry_init (cairo_t *cr, struct xrchart_geometry *geom,
 
   cairo_set_line_width (cr, 1.0);
 
-  cairo_rectangle (cr, geom->data_left, geom->data_bottom,
-                   geom->data_right - geom->data_left,
-                   geom->data_top - geom->data_bottom);
+  cairo_rectangle (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min,
+                   geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min,
+                   geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min);
   cairo_stroke (cr);
 }
 
@@ -226,14 +226,14 @@ draw_tick (cairo_t *cr, const struct xrchart_geometry *geom,
   const int tickSize = 10;
   double x, y;
 
-  cairo_move_to (cr, geom->data_left, geom->data_bottom);
+  cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min);
 
-  if (orientation == TICK_ABSCISSA)
+  if (orientation == SCALE_ABSCISSA)
     {
       cairo_rel_move_to (cr, position, 0);
       cairo_rel_line_to (cr, 0, -tickSize);
     }
-  else if (orientation == TICK_ORDINATE)
+  else if (orientation == SCALE_ORDINATE)
     {
       cairo_rel_move_to (cr, 0, position);
       cairo_rel_line_to (cr, -tickSize, 0);
@@ -253,9 +253,9 @@ draw_tick (cairo_t *cr, const struct xrchart_geometry *geom,
 
       va_start (ap, label);
       s = xvasprintf (label, ap);
-      if (orientation == TICK_ABSCISSA)
+      if (orientation == SCALE_ABSCISSA)
         xrchart_label (cr, 'c', 't', geom->font_size, s);
-      else if (orientation == TICK_ORDINATE)
+      else if (orientation == SCALE_ORDINATE)
         {
           if (fabs (position) < DBL_EPSILON)
            cairo_rel_move_to (cr, 0, 10);
@@ -276,7 +276,7 @@ xrchart_write_title (cairo_t *cr, const struct xrchart_geometry *geom,
   char *s;
 
   cairo_save (cr);
-  cairo_move_to (cr, geom->data_left, geom->title_bottom);
+  cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->title_bottom);
 
   va_start(ap, title);
   s = xvasprintf (title, ap);
@@ -288,55 +288,55 @@ xrchart_write_title (cairo_t *cr, const struct xrchart_geometry *geom,
 }
 
 
-/* Set the scale for the abscissa */
-void
-xrchart_write_xscale (cairo_t *cr, struct xrchart_geometry *geom,
-                    double min, double max, int ticks)
+/* Set the scale for the ordinate */
+static void
+xrchart_write_scale (cairo_t *cr, struct xrchart_geometry *geom,
+                    double smin, double smax, int ticks, enum tick_orientation orient)
 {
-  double x;
+  double y;
 
   const double tick_interval =
-    chart_rounded_tick ((max - min) / (double) ticks);
+    chart_rounded_tick ((smax - smin) / (double) ticks);
 
-  geom->x_max = ceil (max / tick_interval) * tick_interval;
-  geom->x_min = floor (min / tick_interval) * tick_interval;
-  geom->abscissa_scale = fabs(geom->data_right - geom->data_left) /
-    fabs(geom->x_max - geom->x_min);
+  geom->axis[orient].max = ceil (smax / tick_interval) * tick_interval;
+  geom->axis[orient].min = floor (smin / tick_interval) * tick_interval;
 
-  for (x = geom->x_min; x <= geom->x_max; x += tick_interval)
-    draw_tick (cr, geom, TICK_ABSCISSA,
-               (x - geom->x_min) * geom->abscissa_scale, "%g", x);
-}
+  geom->axis[orient].scale = (fabs (geom->axis[orient].data_max - geom->axis[orient].data_min)
+     / fabs (geom->axis[orient].max - geom->axis[orient].min));
 
+  /*
+  geom->axis[orient].scale = (fabs (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min)
+     / fabs (geom->axis[orient].max - geom->axis[orient].min));
+  */
+
+
+  for (y = geom->axis[orient].min; y <= geom->axis[orient].max; y += tick_interval)
+    draw_tick (cr, geom, orient,
+              (y - geom->axis[orient].min) * geom->axis[orient].scale, "%g", y);
+}
 
-/* Set the scale for the ordinate */
 void
 xrchart_write_yscale (cairo_t *cr, struct xrchart_geometry *geom,
                     double smin, double smax, int ticks)
 {
-  double y;
-
-  const double tick_interval =
-    chart_rounded_tick ((smax - smin) / (double) ticks);
-
-  geom->y_max = ceil (smax / tick_interval) * tick_interval;
-  geom->y_min = floor (smin / tick_interval) * tick_interval;
-
-  geom->ordinate_scale =
-    (fabs (geom->data_top - geom->data_bottom)
-     / fabs (geom->y_max - geom->y_min));
+  xrchart_write_scale (cr, geom, smin, smax, ticks, SCALE_ORDINATE);
+}
 
-  for (y = geom->y_min; y <= geom->y_max; y += tick_interval)
-    draw_tick (cr, geom, TICK_ORDINATE,
-              (y - geom->y_min) * geom->ordinate_scale, "%g", y);
+/* Set the scale for the abscissa */
+void
+xrchart_write_xscale (cairo_t *cr, struct xrchart_geometry *geom,
+                    double smin, double smax, int ticks)
+{
+  xrchart_write_scale (cr, geom, smin, smax, ticks, SCALE_ABSCISSA);
 }
 
+
 /* Write the abscissa label */
 void
 xrchart_write_xlabel (cairo_t *cr, const struct xrchart_geometry *geom,
                     const char *label)
 {
-  cairo_move_to (cr, geom->data_left, geom->abscissa_top);
+  cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->abscissa_top);
   xrchart_label (cr, 'l', 't', geom->font_size, label);
 }
 
@@ -346,7 +346,7 @@ xrchart_write_ylabel (cairo_t *cr, const struct xrchart_geometry *geom,
                     const char *label)
 {
   cairo_save (cr);
-  cairo_translate (cr, -geom->data_bottom, -geom->ordinate_right);
+  cairo_translate (cr, -geom->axis[SCALE_ORDINATE].data_min, -geom->ordinate_right);
   cairo_move_to (cr, 0, 0);
   cairo_rotate (cr, M_PI / 2.0);
   xrchart_label (cr, 'l', 'x', geom->font_size, label);
@@ -362,7 +362,7 @@ xrchart_write_legend (cairo_t *cr, const struct xrchart_geometry *geom)
   const int xpad = 10;
   const int ypad = 10;
   const int swatch = 20;
-  const int legend_top = geom->data_top;
+  const int legend_top = geom->axis[SCALE_ORDINATE].data_max;
   const int legend_bottom = legend_top -
     (vstep * geom->n_datasets + 2 * ypad );
 
@@ -425,8 +425,8 @@ void
 xrchart_datum (cairo_t *cr, const struct xrchart_geometry *geom,
              int dataset UNUSED, double x, double y)
 {
-  double x_pos = (x - geom->x_min) * geom->abscissa_scale + geom->data_left;
-  double y_pos = (y - geom->y_min) * geom->ordinate_scale + geom->data_bottom;
+  double x_pos = (x - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
+  double y_pos = (y - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
 
   xrchart_draw_marker (cr, x_pos, y_pos, XRMARKER_SQUARE, 15);
 }
@@ -444,10 +444,10 @@ void
 xrchart_vector (cairo_t *cr, struct xrchart_geometry *geom, double x, double y)
 {
   const double x_pos =
-    (x - geom->x_min) * geom->abscissa_scale + geom->data_left ;
+    (x - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min ;
 
   const double y_pos =
-    (y - geom->y_min) * geom->ordinate_scale + geom->data_bottom ;
+    (y - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min ;
 
   if (geom->in_path)
     cairo_line_to (cr, x_pos, y_pos);
@@ -488,10 +488,10 @@ xrchart_line(cairo_t *cr, const struct xrchart_geometry *geom,
       y2 = slope * x2 + intercept;
     }
 
-  y1 = (y1 - geom->y_min) * geom->ordinate_scale + geom->data_bottom;
-  y2 = (y2 - geom->y_min) * geom->ordinate_scale + geom->data_bottom;
-  x1 = (x1 - geom->x_min) * geom->abscissa_scale + geom->data_left;
-  x2 = (x2 - geom->x_min) * geom->abscissa_scale + geom->data_left;
+  y1 = (y1 - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
+  y2 = (y2 - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale + geom->axis[SCALE_ORDINATE].data_min;
+  x1 = (x1 - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
+  x2 = (x2 - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale + geom->axis[SCALE_ABSCISSA].data_min;
 
   cairo_move_to (cr, x1, y1);
   cairo_line_to (cr, x2, y2);

diff --git a/src/output/cairo-chart.h b/src/output/cairo-chart.h
index 1a23dd179329cde657b12a98cd6c5f1ef1c8b05b..5e8123ed1a6617408522043c9f0789aefc2818b8 100644 (file)
--- a/src/output/cairo-chart.h
+++ b/src/output/cairo-chart.h
@@ -31,16 +31,20 @@ struct xrchart_colour
     uint8_t blue;
   };
 
+struct xrchart_axis
+{
+  int data_max;
+  int data_min;
+
+  double scale;
+  double min;
+  double max;
+};
+
 /* The geometry of a chart. */
 struct xrchart_geometry
   {
-    int data_top;
-    int data_right;
-    int data_bottom;
-    int data_left;
-
     int abscissa_top;
-
     int ordinate_right;
 
     int title_bottom;
@@ -57,12 +61,9 @@ struct xrchart_geometry
     struct xrchart_colour fill_colour;
 
     /* Stuff particular to cartesians and boxplots. */
-    double ordinate_scale;
-    double abscissa_scale;
-    double x_min;
-    double x_max;
-    double y_min;
-    double y_max;
+    struct xrchart_axis axis[2];
+
+    /* True iff a path is currently being drawn */
     bool in_path;
   };
 
@@ -75,8 +76,8 @@ extern const struct xrchart_colour data_colour[];
 
 enum tick_orientation
   {
-    TICK_ABSCISSA=0,
-    TICK_ORDINATE
+    SCALE_ABSCISSA=0,
+    SCALE_ORDINATE
   };
 
 enum xrmarker_type

diff --git a/src/output/charts/boxplot-cairo.c b/src/output/charts/boxplot-cairo.c
index 1660e86b2db1455d9a4a01bb22b4ace7ec568463..6aaa600be99d8eda6733d9e7d85274dea34a2825 100644 (file)
--- a/src/output/charts/boxplot-cairo.c
+++ b/src/output/charts/boxplot-cairo.c
@@ -31,7 +31,7 @@ static void
 draw_case (cairo_t *cr, const struct xrchart_geometry *geom, double centreline,
           const struct outlier *outlier)
 {
-  double y = geom->data_bottom + (outlier->value - geom->y_min) * geom->ordinate_scale;
+  double y = geom->axis[SCALE_ORDINATE].data_min + (outlier->value - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale;
   xrchart_draw_marker (cr, centreline, y,
                      outlier->extreme ? XRMARKER_ASTERISK : XRMARKER_CIRCLE,
                      20);
@@ -65,14 +65,14 @@ boxplot_draw_box (cairo_t *cr, const struct xrchart_geometry *geom,
   box_whisker_whiskers (bw, whisker);
   box_whisker_hinges (bw, hinge);
 
-  box_bottom = geom->data_bottom + (hinge[0] - geom->y_min ) * geom->ordinate_scale;
+  box_bottom = geom->axis[SCALE_ORDINATE].data_min + (hinge[0] - geom->axis[SCALE_ORDINATE].min ) * geom->axis[SCALE_ORDINATE].scale;
 
-  box_top = geom->data_bottom + (hinge[2] - geom->y_min ) * geom->ordinate_scale;
+  box_top = geom->axis[SCALE_ORDINATE].data_min + (hinge[2] - geom->axis[SCALE_ORDINATE].min ) * geom->axis[SCALE_ORDINATE].scale;
 
-  bottom_whisker = geom->data_bottom + (whisker[0] - geom->y_min) *
-    geom->ordinate_scale;
+  bottom_whisker = geom->axis[SCALE_ORDINATE].data_min + (whisker[0] - geom->axis[SCALE_ORDINATE].min) *
+    geom->axis[SCALE_ORDINATE].scale;
 
-  top_whisker = geom->data_bottom + (whisker[1] - geom->y_min) * geom->ordinate_scale;
+  top_whisker = geom->axis[SCALE_ORDINATE].data_min + (whisker[1] - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale;
 
   /* Draw the box */
   cairo_rectangle (cr,
@@ -94,10 +94,10 @@ boxplot_draw_box (cairo_t *cr, const struct xrchart_geometry *geom,
   cairo_set_line_width (cr, cairo_get_line_width (cr) * 5);
   cairo_move_to (cr,
                  box_left,
-                 geom->data_bottom + (hinge[1] - geom->y_min) * geom->ordinate_scale);
+                 geom->axis[SCALE_ORDINATE].data_min + (hinge[1] - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale);
   cairo_line_to (cr,
                  box_right,
-                 geom->data_bottom + (hinge[1] - geom->y_min) * geom->ordinate_scale);
+                 geom->axis[SCALE_ORDINATE].data_min + (hinge[1] - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale);
   cairo_stroke (cr);
   cairo_restore (cr);
 
@@ -131,7 +131,7 @@ boxplot_draw_box (cairo_t *cr, const struct xrchart_geometry *geom,
     }
 
   /* Draw  tick  mark on x axis */
-  draw_tick(cr, geom, TICK_ABSCISSA, box_centre - geom->data_left, "%s", name);
+  draw_tick(cr, geom, SCALE_ABSCISSA, box_centre - geom->axis[SCALE_ABSCISSA].data_min, "%s", name);
 }
 
 static void
@@ -141,21 +141,21 @@ boxplot_draw_yscale (cairo_t *cr, struct xrchart_geometry *geom,
   double y_tick;
   double d;
 
-  geom->y_max = y_max;
-  geom->y_min = y_min;
+  geom->axis[SCALE_ORDINATE].max = y_max;
+  geom->axis[SCALE_ORDINATE].min = y_min;
 
-  y_tick = chart_rounded_tick (fabs (geom->y_max - geom->y_min) / 5.0);
+  y_tick = chart_rounded_tick (fabs (geom->axis[SCALE_ORDINATE].max - geom->axis[SCALE_ORDINATE].min) / 5.0);
 
-  geom->y_min = (ceil (geom->y_min / y_tick) - 1.0) * y_tick;
+  geom->axis[SCALE_ORDINATE].min = (ceil (geom->axis[SCALE_ORDINATE].min / y_tick) - 1.0) * y_tick;
 
-  geom->y_max = (floor (geom->y_max / y_tick) + 1.0) * y_tick;
+  geom->axis[SCALE_ORDINATE].max = (floor (geom->axis[SCALE_ORDINATE].max / y_tick) + 1.0) * y_tick;
 
-  geom->ordinate_scale = (fabs (geom->data_top - geom->data_bottom)
-                          / fabs (geom->y_max - geom->y_min));
+  geom->axis[SCALE_ORDINATE].scale = (fabs (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min)
+                          / fabs (geom->axis[SCALE_ORDINATE].max - geom->axis[SCALE_ORDINATE].min));
 
-  for (d = geom->y_min; d <= geom->y_max; d += y_tick)
-    draw_tick (cr, geom, TICK_ORDINATE,
-               (d - geom->y_min) * geom->ordinate_scale, "%g", d);
+  for (d = geom->axis[SCALE_ORDINATE].min; d <= geom->axis[SCALE_ORDINATE].max; d += y_tick)
+    draw_tick (cr, geom, SCALE_ORDINATE,
+               (d - geom->axis[SCALE_ORDINATE].min) * geom->axis[SCALE_ORDINATE].scale, "%g", d);
 }
 
 void
@@ -169,11 +169,11 @@ xrchart_draw_boxplot (const struct chart_item *chart_item, cairo_t *cr,
   boxplot_draw_yscale (cr, geom, boxplot->y_max, boxplot->y_min);
   xrchart_write_title (cr, geom, "%s", chart_item->title);
 
-  box_width = (geom->data_right - geom->data_left) / boxplot->n_boxes / 2.0;
+  box_width = (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / boxplot->n_boxes / 2.0;
   for (i = 0; i < boxplot->n_boxes; i++)
     {
       const struct boxplot_box *box = &boxplot->boxes[i];
-      const double box_centre = (i * 2 + 1) * box_width + geom->data_left;
+      const double box_centre = (i * 2 + 1) * box_width + geom->axis[SCALE_ABSCISSA].data_min;
       boxplot_draw_box (cr, geom, box_centre, box_width, box->bw, box->label);
     }
 }

diff --git a/src/output/charts/piechart-cairo.c b/src/output/charts/piechart-cairo.c
index 9e55c56f46a0b8d83ef4b0cf2b9ad4489f1c8fec..7b847f123ef43663b7e26a8660fd73b68671b85a 100644 (file)
--- a/src/output/charts/piechart-cairo.c
+++ b/src/output/charts/piechart-cairo.c
@@ -57,17 +57,17 @@ xrchart_draw_piechart (const struct chart_item *chart_item, cairo_t *cr,
   double angle;
   int i;
 
-  centre_x = (geom->data_right + geom->data_left) / 2.0 ;
-  centre_y = (geom->data_top + geom->data_bottom) / 2.0 ;
+  centre_x = (geom->axis[SCALE_ABSCISSA].data_max + geom->axis[SCALE_ORDINATE].data_min) / 2.0 ;
+  centre_y = (geom->axis[SCALE_ORDINATE].data_max + geom->axis[SCALE_ORDINATE].data_min) / 2.0 ;
 
-  left_label = geom->data_left + (geom->data_right - geom->data_left)/10.0;
-  right_label = geom->data_right - (geom->data_right - geom->data_left)/10.0;
+  left_label = geom->axis[SCALE_ORDINATE].data_min + (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ORDINATE].data_min)/10.0;
+  right_label = geom->axis[SCALE_ABSCISSA].data_max - (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ORDINATE].data_min)/10.0;
 
-  radius = MIN (5.0 / 12.0 * (geom->data_top - geom->data_bottom),
-                1.0 / 4.0 * (geom->data_right - geom->data_left));
+  radius = MIN (5.0 / 12.0 * (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min),
+                1.0 / 4.0 * (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ORDINATE].data_min));
 
-  radius = MIN (5.0 / 12.0 * (geom->data_top - geom->data_bottom),
-                1.0 / 4.0 * (geom->data_right - geom->data_left));
+  radius = MIN (5.0 / 12.0 * (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min),
+                1.0 / 4.0 * (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ORDINATE].data_min));
 
   xrchart_write_title (cr, geom, "%s", chart_item_get_title (chart_item));
 

diff --git a/src/output/charts/plot-hist-cairo.c b/src/output/charts/plot-hist-cairo.c
index 7c09b6df73091a799cfd1c8fa729f2396ba442c2..9ce4abb3ed09fec2796c25e4077e9520893116fc 100644 (file)
--- a/src/output/charts/plot-hist-cairo.c
+++ b/src/output/charts/plot-hist-cairo.c
@@ -33,7 +33,7 @@ static void
 histogram_write_legend (cairo_t *cr, const struct xrchart_geometry *geom,
                         double n, double mean, double stddev)
 {
-  double y = geom->data_bottom;
+  double y = geom->axis[SCALE_ORDINATE].data_min;
   cairo_save (cr);
 
   if (n != SYSMIS)
@@ -74,18 +74,18 @@ hist_draw_bar (cairo_t *cr, const struct xrchart_geometry *geom,
   double height;
 
   const size_t bins = gsl_histogram_bins (h);
-  const double x_pos = (geom->data_right - geom->data_left) * bar / (double) bins ;
-  const double width = (geom->data_right - geom->data_left) / (double) bins ;
+  const double x_pos = (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) * bar / (double) bins ;
+  const double width = (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / (double) bins ;
 
   assert ( 0 == gsl_histogram_get_range (h, bar, &lower, &upper));
 
   assert ( upper >= lower);
 
   height = gsl_histogram_get (h, bar) /
-    (geom->y_max - geom->y_min) *
-    (geom->data_top - geom->data_bottom);
+    (geom->axis[SCALE_ORDINATE].max - geom->axis[SCALE_ORDINATE].min) *
+    (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min);
 
-  cairo_rectangle (cr, geom->data_left + x_pos, geom->data_bottom,
+  cairo_rectangle (cr, geom->axis[SCALE_ABSCISSA].data_min + x_pos, geom->axis[SCALE_ORDINATE].data_min,
                    width, height);
   cairo_save (cr);
   cairo_set_source_rgb (cr,
@@ -96,7 +96,7 @@ hist_draw_bar (cairo_t *cr, const struct xrchart_geometry *geom,
   cairo_restore (cr);
   cairo_stroke (cr);
 
-  draw_tick (cr, geom, TICK_ABSCISSA,
+  draw_tick (cr, geom, SCALE_ABSCISSA,
              x_pos + width / 2.0, "%g", (upper + lower) / 2.0);
 }
 
@@ -142,20 +142,20 @@ xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
       range = not_used - x_min;
       gsl_histogram_get_range (h->gsl_hist, bins - 1, &not_used, &x_max);
 
-      abscissa_scale = (geom->data_right - geom->data_left) / (x_max - x_min);
-      ordinate_scale = (geom->data_top - geom->data_bottom) /
+      abscissa_scale = (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / (x_max - x_min);
+      ordinate_scale = (geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min) /
        gsl_histogram_max_val (h->gsl_hist);
 
-      cairo_move_to (cr, geom->data_left, geom->data_bottom);
-      for (d = geom->data_left;
-          d <= geom->data_right;
-          d += (geom->data_right - geom->data_left) / 100.0)
+      cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min);
+      for (d = geom->axis[SCALE_ABSCISSA].data_min;
+          d <= geom->axis[SCALE_ABSCISSA].data_max;
+          d += (geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min) / 100.0)
        {
-         const double x = (d - geom->data_left) / abscissa_scale + x_min;
+         const double x = (d - geom->axis[SCALE_ABSCISSA].data_min) / abscissa_scale + x_min;
          const double y = h->n * range *
            gsl_ran_gaussian_pdf (x - h->mean, h->stddev);
 
-          cairo_line_to (cr, d, geom->data_bottom  + y * ordinate_scale);
+          cairo_line_to (cr, d, geom->axis[SCALE_ORDINATE].data_min  + y * ordinate_scale);
 
        }
       cairo_stroke (cr);