The code in Gruff looks right, so I suspect a missing feature or bug in RMagick4J.

this is my first time using github, so let me know if I'm putting this in the wrong spot.
line.rb:
line 156 prevents prev_x and prev_y from ever being set to nil..

That means line 181 won't need to check for null value.

I'm am trying to set the font used in my Gruff charts.

I am on Rails 3.2.11 and I'm using the asset pipeline.

I am using g.font = font_path("rokkitt-bold-webfont.ttf") where g = Gruff::StackedBar.new.

At the command line I can see this path expands to "/assets/rokkitt-bold-webfont.ttf"

Entering that URL into the browser I can see that it points to the font as it attempts to save the font as a download.

I know the font is valid as I'm using it successfully in my HTML.

Is the font method broken with the asset pipeline?

What do we have to do to call Gruff production quality?

Is anybody still maintaining this project?

aoeuoaeu

g.write('gc_chart.png')
g.write('gc_chart.gif')
g.write('gc_chart.jpg')

When writing the same chart multiple times, it gains a "shadow" where the chart has been rendered on top of itself.

This is not an issue.

From what I've read, it is possible to add space between bars. And how about group of bars?

I mean, is it possible to define some spacing between bars and another spacing between groups of bars? If not, here is my feature request :)

Congratulations for Gruff!

I would expect the following code to draw a baseline at y=3, two thirds of the way between y=1 and y=4:

require 'gruff'

g = Gruff::Line.new
g.title = "My Graph" 

g.data("Apples", [1, 2, 3, 4, 4, 3])
g.data("Oranges", [4, 8, 7, 9, 8, 9])
g.data("Watermelon", [2, 3, 1, 5, 6, 8])
g.data("Peaches", [9, 9, 10, 8, 7, 9])

g.labels         = {0 => '2003', 2 => '2004', 4 => '2005'}
g.baseline_value = 3

g.write('my_fruity_graph.jpg') 

However, as you can see from the image below, the baseline is being drawn very close to y=4. I'm not sure whether I've missed something about how baseline_value is meant to work, but this looks like it might be a bug.

For some reason when i pull the gem into my app I am unable to use Themes. otherwise it seems to work fine.

How can I set logarithmic scale for Y axis? It seems that gruff doesn't support that yet, but is there some workaround how to achieve it now? Thanks.

Currently if you set a label like "Score (%)" it is printed as "Score (" since RMagick uses the "%" for special values.

http://www.imagemagick.org/RMagick/doc/draw.html#annotate

I propose we escape the "%" to allow it to be displayed correctly. This removes the feature of inserting image-specific values as described in the link above, but I think that is an unimportant and maybe undesired feature.

Any opinions?

I'm generating JPG graphs and when they are set to the default size (800x600 ?) they look great. However, if I try to generate a smaller graph, say 200x200, it looks awful. Is there something I'm doing wrong?

Thanx!
Richard

I want to generate Side Stacked Bar using gruff library. but i am not bale to understand how to pass data,show labels and color for labels.
could you please give one small example for generating side stack bar

Sorry to disturb, but i`ve faced some problem with templates from documentation:

  g = Gruff::Line.new
  g.title = "A Line Graph"
  g.data 'Fries', [20, 23, 19, 8]
  g.data 'Hamburgers', [50, 19, 99, 29]
  g.write("test/output/line.png")

this produces:

ZeroDivisionError: divided by 0

I tried to build a new gem for gruff after I ran rake in ruby and jruby. I get the following errors:

C:\Users\Roger\Documents\GitHub\gruff>gem build gruff.gemspec
ERROR: While executing gem ... (Gem::InvalidSpecificationException)
["test/output/bar_y_increment_2.0.png", "test/output/dot_y_increment_2.0.png", "test/output_java
/bar_y_increment_2.0.png", "test/output_java/dot_y_increment_2.0.png"] are not files

This is due to the fact that the test are generating an extra ".0" in some file names. For instance, "bar_y_increment_2.0.png" has become "bar_y_increment_2.0.0.png". I think I can create a fix for this.

How to distinguish overlapping point so we display or get to know all dots at one point.
please find attached screenshot

If you have 3 data points, ej (20, 30, 25) the first data point looks just like a line which goes to the origin as seen in http://albertein.com.mx/bmi.png

Merge the xy branch to enable Line charts with dataxy data sets.

Allow placing the legend inside the chart either at given coordinates or anchored to a compass direction or even centered.

Currently Gruff::Line support hiding dots for all lines by setting g.hide_dots = false. It would be nice to have the possibility to hide dots for individual lines as well.

One possibility would be to allow g.data to take more options than just color.

What do you think?

As far as I can see, the dots in the dot graph are drawn in the wrong position.

Also, the y_axis_increment is not respected.

I am pushing a fix for both.

I would like to be able to add the actual values to a graph. For example, on a bar graph, it would be nice to have the actual value on top of or inside the bar. This makes it easier to see where a number lies instead of having to guess by looking at the axis.

Is this possible?

Gruff depends on RMagick, so it should be in it's gem dependencies.

On side bar and side stacked bar types, when a field value is zero, a bar with non-zero width is still drawn.

This patch seems to resolve the issue in my case:

diff --git a/lib/gruff/side_bar.rb b/lib/gruff/side_bar.rb
index 6733a22..090cd8b 100644
--- a/lib/gruff/side_bar.rb
+++ b/lib/gruff/side_bar.rb
@@ -44,7 +44,7 @@ class Gruff::SideBar < Gruff::Base

         height[point_index] += (data_point * @graph_width)

-        @d           = @d.rectangle(left_x, left_y, right_x, right_y)
+        @d           = @d.rectangle(left_x, left_y, right_x, right_y) unless difference <= 0

         # Calculate center based on bar_width and current row
         label_center = @graph_top + (@bars_width * point_index + @bars_width / 2)
diff --git a/lib/gruff/side_stacked_bar.rb b/lib/gruff/side_stacked_bar.rb
index 0b51070..9c3be27 100644
--- a/lib/gruff/side_stacked_bar.rb
+++ b/lib/gruff/side_stacked_bar.rb
@@ -52,7 +52,7 @@ class Gruff::SideStackedBar < Gruff::SideBar
          length[point_index] += difference
         height[point_index] += (data_point * @graph_width - 2)

-        @d = @d.rectangle(left_x, left_y, right_x, right_y)
+        @d = @d.rectangle(left_x, left_y, right_x, right_y) unless difference <= 0

         # Calculate center based on bar_width and current row
         label_center = @graph_top + (@bar_width * point_index) + (@bar_width * @bar_spacing / 2.0)

Merge the scatter branch to enable Scatter charts.

Code:

line_data = [99.931, 99.876, 99.948, 99.98, 99.985, 99.924, 99.98, 100.0]

g = Gruff::Line.new
g.marker_font_size = 10
g.data("test",line_data)
g.write("test.png")

Output:

Details:
Notice the markers report "0.99936E2" for example instead of "99.936".
Is there a way to force the markers to a certain number of decimal places?

It is currently possible to add horizontal background lines to graphs, but not vertical background lines. It should be possible to add both. A sensible strategy would be to match the vertical background lines to the labels on the x axis.

Add a vertical line at x = 0

gruff should depend on rmagick and gruff-java should depend on rmagick4j.

The build is currently failing on Travis:

https://travis-ci.org/topfunky/gruff

Also, it would be nice to add the Build Status image/buttton to our ReadMe like you can see here when you scroll down to the ReadMe:

https://github.com/jruby/jruby

Example image: https://github.com/topfunky/gruff/blob/master/test/output/line_xy.png

The '2003' label should correspond with 0, '2004' with 2
Consider Graph Apples (yellow): It has a datapoint on [1, 1]

Confusingly, the yellow bar is at value 1, exactly about the 2003 label.
If we consider the labels, off-by-one with the X datavalues, the [3, 2] should be right about the '2004' label, which is not the case (but [4,5] is).

(Copied from code docs)

# g.dataxy("Apples", [1,3,4,5,6,10], [1, 2, 3, 4, 4, 3])
...
# g.data("Capples", [1, 1, 2, 2, 3, 3])
# #labels will be drawn at the x locations of the 1st dataset that you
# #passed in. In this example the lables are drawn at x locations 1,4,6

Since the green bar should have the same X values as the green bar, I expect the datapoints to ly on the same Y value, which is totally not the case as can be seen on the second datapoint (slightly shifted to the left).

Also note that the documentation is wrong as it should say at "x locations 1,3,4,5,6,10"

[nathan@psi onderzoeksstage]$ bundle show
Gems included by the bundle:
  * bundler (1.2.1)
  * gruff (0.3.7)
  * rmagick (2.13.1)
[nathan@psi onderzoeksstage]$ 

Hi all!

Currently, "sort" is set to default true which sorts the data sets on average value, largest to smallest. I think the default should be to draw the data sets as they were given. Any opinions?

As a separate feature, some graphs, like "area", should draw the largest values first to avoid hiding the smaller values. This behaviour is chart type dependent.

When the data set is sorted today, the legend is not sorted. I propose we sort the legend to correspond to the order of the data sets.

The automatically generated colours for each data set should be picked after the data sets have been sorted, to comply with the given theme. This has the effect of the developer being able to set the colours (or theme) after the data sets have been given. Some test examples change because of this, for the better, I think.

I have the implementation for this ready, so please be quick with comments.

Is it possible to explicitly specify how given data should overlap? Currently it seems rendering is done from highest to lowest, resulting in data (with lowest totals) being rendered in front of everything else.

Consider the following.

graph = Gruff::Line.new

graph.theme = {
  background: 'transparent'
}

graph.labels = {
  0 => "2013-07-01",
  1 => "2013-07-08"
}

graph.data('first',  [1, 2])
graph.data('second', [2, 3])

graph.write

This will result in the line first being rendered above line second. Is it possible to adjust this by explicitly enforcing what level a line should be rendered at?

I am thinking we release Gruff 0.4.0 on monday. Are there any blockers?

Factor out separate XY module for LineXY and Scatter.

Override draw_label to take X-position instead of sample position.

This is somehow triggered by setting colours.

Tracked as Serabe/RMagick4J#16

I created a simple line graph with the following code:

require 'gruff'

g = Gruff::Line.new(400)
g.title = "Transparent Background"
g.theme = {
:colors => ['black', 'grey'],
:marker_color => 'grey',
:font_color => 'black',
:background_colors => 'white'
}

g.labels = {
0 => '5/6',
1 => '5/15',
2 => '5/24',
3 => '5/30',
}
g.y_axis_label = "Bushels"
g.x_axis_label = "Date"
g.data(:apples, [-1, 0, 4, -4])
g.data(:peaches, [10, 8, 6, 3])
g.write("line_transparent.png")

The generated image looks like this:

The "Bushels" y-label should go in the other direction IMHO. Do you agree? If so, this is a simple fix and I can create a Pull Request (my first, so be patient) if necessary.

Is there any way to set the encoding to uft-8?? i am using the armenian language and whenever i create a graph all my labels are replaced with question marks.