SVGGraph 3D Bar Graphs

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SVGGraph currently contains these classes for drawing orthographic projection 3D bar graphs: Bar3DGraph; StackedBar3DGraph; GroupedBar3DGraph; StackedGroupedBar3DGraph; CylinderGraph; StackedCylinderGraph; GroupedCylinderGraph; StackedGroupedCylinderGraph. An example of each type is shown below.

DoughRayMeSoFarLard01020304050
Bar3DGraph
DoughRayMeSoFarLard01020304050
CylinderGraph
DoughRayMeSoFarLardTea020406080
StackedBar3DGraph
DoughRayMeSoFarLardTea020406080
StackedCylinderGraph
DoughRayMeSoFarLardTea01020304050
GroupedBar3DGraph
DoughRayMeSoFarLardTea01020304050
GroupedCylinderGraph
DoughRayMeSoFarLardTea020406080
StackedGroupedBar3DGraph
DoughRayMeSoFarLardTea020406080
StackedGroupedCylinderGraph

Zero and null

One advantage of using 3D bar graphs over flat bar graphs is that graph entries with a value of 0 appear as a parallelogram. This means that tooltips and links will work, and it also allows you to see whether values are 0 or null.

OneNullFourZeroFive012345
Null and 0 on BarGraph
OneNullFourZeroFive012345
Null and 0 on Bar3DGraph

In the 2D bar graph above, “Null” and “Zero” are both empty columns, whereas in the 3D bar graph the “Zero” column contains a bar with a height of 0 and the “Null” column is empty.

Example code

Here are the settings and PHP code used to generate the graphs above:

<?php
require_once 'SVGGraph/autoloader.php';

$settings = array(
  'back_colour' => '#eee',
  'stroke_colour' => '#000',
  'back_stroke_width' => 0,
  'back_stroke_colour' => '#eee',
  'axis_colour' => '#333',
  'axis_overlap' => 2,
  'axis_font' => 'Arial',
  'axis_font_size' => 10,
  'grid_colour' => '#666',
  'label_colour' => '#000',
  'pad_right' => 20,
  'pad_left' => 20,
  'link_base' => '/',
  'link_target' => '_top',
  'project_angle' => 45,
  'minimum_grid_spacing' => 20
);

$values = array(
 array('Dough' => 30, 'Ray' => 50, 'Me' => 40, 'So' => 25, 'Far' => 45, 'Lard' => 35),
 array('Dough' => 20, 'Ray' => 30, 'Me' => 20, 'So' => 15, 'Far' => 25, 'Lard' => 35,
  'Tea' => 45)
);

$colours = array(
  array('red','yellow'), array('blue','white')
);
$links = array(
  'Dough' => 'jpegsaver.php', 'Ray' => 'crcdropper.php',
  'Me' => 'svggraph.php'
);

$graph = new Goat1000\SVGGraph\SVGGraph(300, 200, $settings);

$graph->colours($colours);
$graph->values($values);
$graph->links($links);
$graph->render('Bar3DGraph');

This code is almost identical to the example on the bar graphs page, but with the addition of the project_angle option and using the “Bar3DGraph” class name in the call to $graph->render().

The StackedGroupedBar3DGraph and StackedGroupedCylinderGraph work in the same way as the StackedGroupedBarGraph, requiring the use of the stack_group option to specify which bars should be stacked.

Shading with overlays

To improve the depth effect, the 3D bar graphs support shading the different parts of the bars using overlays for the side, top and front sections. The overlay is a solid colour with an opacity that allows the bar colour, gradient or pattern underneath to show through.

DoughRayMeSoFarLard01020304050
More intense overlays
bar_top_overlay_opacity = 0.7
bar_side_overlay_opacity = 0.7
DoughRayMeSoFarLard01020304050
Shade front instead of side
bar_top_overlay_opacity = 0.7
bar_side_overlay_opacity = 0
bar_front_overlay_opacity = 0.7

For the first example, the default overlay values have been increased to make the effect more pronounced. The top of the bar uses a white overlay by default, the front and side use a black overlay (with an opacity of 0 for the front, which disables the overlay completely).

The second example swaps the opacity value from the side to the front, making it look like the bars are lit from the side. You could also change the overlay colours to tint the bar sections instead of just making them lighter or darker.

Cylinder graph gradient overlay

The cylinder graphs use a partially transparent gradient overlay to darken the sides of the cylinder for a greater depth effect. The default gradient option is shown here:

$settings['depth_shade_gradient'] = array(
  "black:0.6", "black:0", "black:0.9", "h"
);

The final 'h' in the array of colours tells SVGGraph to create a horizontal gradient, otherwise the gradient would be vertical and not help with the depth effect.

Skewing the bar tops and sides

The skew_side and skew_top options control how the top and side sections of each bar are drawn. When the bars are filled with solid colours it makes no difference, but for pattern fills the difference is obvious:

ABCDEF01020304050
No skewing
skew_side = false
skew_top = false
ABCDEF01020304050
Skew top and side
skew_side = true
skew_top = true

In the first example above, both skew options are turned off. The top is filled with the main colour and the side is filled with the same pattern as the front of the bar. The second example shows how the patterns and gradients are slanted to match the angle of the side and top sections of the bars.

Settings

These options are common to all graph types.

General options + Show table

This table lists the options that are common to all the grid-based graph types - the options for grid spacing, axis labelling, etc.

Grid-based graph options - Hide table

OptionDefaultDescription
axis_colour "rgb(0,0,0)" Colour of axis lines and text.
axis_colour_h NULL Colour of horizontal axis.
axis_colour_v NULL Colour of vertical axis.
axis_fallback_max 1 Sets a fallback value for the axis maximum when the graph contains all zero values.
axis_font "Courier New" Font for axis division labels.
axis_font_adjust 0.6 Font aspect ratio of axis division text.
axis_font_adjust_h NULL Font aspect ratio of horizontal axis division text.
axis_font_adjust_v NULL Font aspect ratio of vertical axis division text.
axis_font_h NULL Font for horizontal axis division labels.
axis_font_size 10 Font size for axis division labels.
axis_font_size_h NULL Font size for horizontal axis division labels.
axis_font_size_v NULL Font size for vertical axis division labels.
axis_font_v NULL Font for vertical axis division labels.
axis_font_weight "normal" Font weight for axis division labels.
axis_font_weight_h null Font weight for horizontal axis division labels.
axis_font_weight_v null Font weight for vertical axis division labels.
axis_label_position 0.5 Sets position of axis label as a fraction of the axis length.
axis_label_position_h null Sets position of horizontal axis label as a fraction of the axis length.
axis_label_position_v null Sets position of vertical axis label as a fraction of the axis length.
axis_levels_h null Sets the number of levels of horizontal axis division labels.
axis_levels_v null Sets the number of levels of vertical axis division labels.
axis_max_h NULL Maximum value for horizontal axis.
axis_max_v NULL Maximum value for vertical axis.
axis_min_h NULL Minimum value for horizontal axis.
axis_min_v NULL Minimum value for vertical axis.
axis_overlap 5 Distance axes extend past grid.
axis_right false Enables axis on right of grid.
axis_space 15 Space between axes on the right of the graph.
axis_stroke_width 2 Width of axis lines.
axis_stroke_width_h NULL Width of horizontal axis line.
axis_stroke_width_v NULL Width of vertical axis line.
axis_text_angle_h 0 Angle of horizontal axis division text.
axis_text_angle_v 0 Angle of vertical axis division text.
axis_text_back_colour null Background colour for axis division labels.
axis_text_back_colour_h null Background colour for horizontal axis division labels.
axis_text_back_colour_v null Background colour for vertical axis division labels.
axis_text_callback NULL Callback function for axis division text labels.
axis_text_callback_x NULL Callback function for X axis division text labels.
axis_text_callback_y NULL Callback function for Y axis division text labels.
axis_text_colour NULL Colour of axis division labels.
axis_text_colour_h NULL Colour of horizontal axis division labels.
axis_text_colour_v NULL Colour of vertical axis division labels.
axis_text_line_spacing null Sets line spacing for axis division labels.
axis_text_line_spacing_h null Sets line spacing for horizontal axis division labels.
axis_text_line_spacing_v null Sets line spacing for vertical axis division labels.
axis_text_location "grid" Position of axis text when graph contains negative numbers.
axis_text_location_h null Position of horizontal axis text when graph contains negative numbers.
axis_text_location_v null Position of vertical axis text when graph contains negative numbers.
axis_text_position "outside" Position of axis division text labels.
axis_text_position_h NULL Position of horizontal axis division text labels.
axis_text_position_v NULL Position of vertical axis division text labels.
axis_text_space 2 Space between axis division text and axis.
axis_text_space_h NULL Space between horizontal axis division text and axis.
axis_text_space_v NULL Space between vertical axis division text and axis.
axis_ticks_x null Specifies positions of axis tick marks for X-axis.
axis_ticks_y null Specifies positions of axis tick marks for Y-axis.
axis_tightness_y 1 Sets the algorithm used to choose Y-axis divisions.
axis_zero_y true Allows graph to pick a non-zero value for bottom of Y-axis.
dataset_axis NULL Enables multiple Y-axes.
datetime_text_format NULL Date format for date/time axis.
datetime_week_start "monday" Week start day for date/time axis.
decimal_digits NULL Number of decimal digits in axis text labels.
decimal_digits_x NULL Number of decimal digits in X axis text labels.
decimal_digits_y NULL Number of decimal digits in Y axis text labels.
division_colour NULL Colour of axis division marks.
division_colour_h NULL Colour of horizontal axis division marks.
division_colour_v NULL Colour of vertical axis division marks.
division_size 3 Length of division marks.
division_size_h NULL Size of horizontal axis division marks.
division_size_v NULL Size of vertical axis division marks.
division_style "out" Style of axis division marks.
division_style_h NULL Style of horizontal axis division marks.
division_style_v NULL Style of vertical axis division marks.
force_block_label_x false Forces block-style labelling for X axis.
grid_back_colour NULL Colour of grid area background.
grid_back_opacity 1 Opacity of grid background fill.
grid_back_stripe false Displays grid background stripes.
grid_back_stripe_colour "rgb(240,240,240)" Colour of grid background stripes.
grid_back_stripe_opacity 1 Opacity of grid background stripes.
grid_bottom NULL Position of bottom of grid.
grid_colour "rgb(220,220,220)" Colour of grid lines.
grid_colour_h NULL Colour of vertical grid lines.
grid_colour_v NULL Colour of horizontal grid lines.
grid_dash NULL Grid lines dash pattern.
grid_dash_h NULL Grid vertical lines dash pattern.
grid_dash_v NULL Grid horizontal lines dash pattern.
grid_division_h NULL Division interval on horizontal axis.
grid_division_v NULL Division interval on vertical axis.
grid_left NULL Position of left side of grid.
grid_right NULL Position of right side of grid.
grid_straight false Enables straight grid lines on radar graph.
grid_stroke_width 1 Sets the thickness of grid lines.
grid_stroke_width_h null Sets the thickness of grid lines drawn from the horizontal axis.
grid_stroke_width_v null Sets the thickness of grid lines drawn from the vertical axis.
grid_subdivision_colour "rgba(220,220,220,0.5)" Colour of grid subdivision lines.
grid_subdivision_colour_h NULL Colour of vertical grid subdivision lines.
grid_subdivision_colour_v NULL Colour of horizontal grid subdivision lines.
grid_subdivision_dash NULL Grid subdivision lines dash pattern.
grid_subdivision_dash_h NULL Grid vertical subdivision lines dash pattern.
grid_subdivision_dash_v NULL Grid horizontal subdivision lines dash pattern.
grid_subdivision_stroke_width null Sets the thickness of grid subdivision lines.
grid_subdivision_stroke_width_h null Sets the thickness of vertical grid subdivision lines.
grid_subdivision_stroke_width_v null Sets the thickness of horizontal grid subdivision lines.
grid_top NULL Position of top of grid.
increment NULL X-axis increment for histograms.
label_colour "rgb(0,0,0)" Colour for axis label text.
label_colour_h NULL Colour for horizontal axis label text.
label_colour_v NULL Colour for vertical axis label text.
label_font "Arial" Font for axis labels.
label_font_h NULL Font for horizontal axis label.
label_font_size 10 Font size for axis labels.
label_font_size_h NULL Font size for horizontal axis label.
label_font_size_v NULL Font size for vertical axis label.
label_font_v NULL Font for vertical axis label.
label_font_weight "normal" Font weight for axis labels.
label_font_weight_h NULL Font weight for horizontal axis label.
label_font_weight_v NULL Font weight for vertical axis label.
label_h "" Text label for horizontal axis.
label_line_spacing null Sets line spacing for axis labels.
label_line_spacing_h null Sets line spacing for label on horizontal axis.
label_line_spacing_v null Sets line spacing for label on vertical axis.
label_space 6 Spacing around axis labels.
label_v "" Text label for vertical axis.
label_x "" Text label for X axis.
label_y "" Text label for Y axis.
limit_text_angle true Limits the angle of axis text to between -90° and +90°.
log_axis_x false Enables logarithmic scale for X-axis.
log_axis_x_base 10 Specifies logarithm base for use on logarithmic X-axis.
log_axis_y false Enables logarithmic Y-axis divisions.
log_axis_y_base 10 Base of the logarithmic axis scale.
minimum_grid_spacing 15 Minimum distance between grid/axis divisions.
minimum_grid_spacing_h NULL Minimum distance between horizontal axis divisions.
minimum_grid_spacing_v NULL Minimum distance between vertical axis divisions.
minimum_subdivision 5 Minimum distance between subdivisions.
minimum_units_y 0 Minimum units to display on Y axis.
show_axes true Enables axis display.
show_axis_h true Enables horizontal axis line.
show_axis_text_h true Enables labelling of horizontal axis divisions.
show_axis_text_v true Enables labelling of vertical axis divisions.
show_axis_v true Enables vertical axis line.
show_divisions true Enables axis division marks.
show_grid true Disables displaying grid.
show_grid_h true Disables displaying horizontal grid lines.
show_grid_subdivisions false Enables displaying grid subdivisions.
show_grid_v true Disables displaying vertical grid lines.
show_subdivisions false Enables axis subdivision marks.
show_x_axis true Enables X-axis on radar graphs.
subdivision_colour NULL Colour of axis subdivision marks.
subdivision_colour_h NULL Colour of horizontal axis subdivision marks.
subdivision_colour_v NULL Colour of vertical axis subdivision marks.
subdivision_h NULL Horizontal axis subdivision interval.
subdivision_size 2 Length of axis subdivision marks.
subdivision_size_h NULL Length of horizontal axis subdivision marks.
subdivision_size_v NULL Length of vertical axis subdivision marks.
subdivision_style "out" Style of axis subdivision marks.
subdivision_style_h NULL Style of horizontal axis subdivision marks.
subdivision_style_v NULL Style of vertical axis subdivision marks.
subdivision_v NULL Vertical axis subdivision interval.
units_before_x NULL Units shown before value on X-axis.
units_before_y NULL Units shown before value on Y-axis.
units_x NULL Units shown after value on X-axis.
units_y NULL Units shown after value on Y-axis.
Grid-based graph options

The options in this table are for use with the 3D bar graphs:

Bar 3D graph options - Hide table

OptionDefaultDescription
bar_space[1] 10 Space between bars
bar_width NULL Width of bar in pixels. Overrides size calculated using bar_space
bar_width_min 1 Minimum width of bar in pixels.
group_space[2] 3 Space between bars of group
project_angle 30 Angle between bar side edges and horizontal axis
skew_side[3] true Skews the side of each bar after filling with pattern or gradient
skew_top[3] true Skews the top of each bar after filling with pattern or gradient instead of filling with solid colour
bar_side_overlay_opacity 0.5 Opacity of overlay on bar sides, 0 for no overlay
bar_side_overlay_colour "#000" Colour of overlay on bar sides
bar_top_overlay_opacity 0.3 Opacity of overlay on bar tops, 0 for no overlay
bar_top_overlay_colour "#fff" Colour of overlay on bar tops
bar_front_overlay_opacity 0 Opacity of overlay on bar fronts, 0 for no overlay
bar_front_overlay_colour "#000" Colour of overlay on bar fronts
depth_shade_gradient[4] "["black:0.6", "black:0",     "black:0.9", "h"]" The gradient to place on top of the sides of cylinders, or NULL for none
stack_group[5] NULL A dataset number (or array of datasets numbers] at which to split the stack
Bar 3D graph options

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