0. Introduction

This project is focused on using STL containers in order to graph data on a one-dimensional and two-dimensional (and if time allows, 3D!) plot. The plot would be written in an svg image, compliant with the W3C standard. The goals of the project are as follows:

• To let users produce a simple plot with minimal intervention by using sane defaults
• To demonstrate how to incorporate SVG images into Boost documentation
• To allow users to easily customize graphs to their heart's content
• To allow the user to talk with the svg_graph class using coordinate units instead of pixels or other arbitrary measures

I have only a student's grasp of C++, so if you have a suggestion to help me with design or implementation, either leave them here or email me at jakevoytko [at] gmail [dot] com

This page will hold examples of what I have implemented thus far, and what my program will be capable of in the future. More complete documentation will be live in a few days on my personal website.

What can it do?

Example

Potential example

vector<double> data1;
deque<double> data2;


svg_plot my_plot("D:\\1D_legend_demo.svg");

// size/scale settings
my_plot.image_size(500, 350);
my_plot.x_scale(-2, 10);
    
// command settings
my_plot.draw_axis()
       .show_legend();

// color settings
my_plot.set_background_color(lightgray)
       .set_legend_background_color(whitesmoke);

// drawing
plot_range(my_plot, data2.begin(), data2.end(), "Lions",  blue);
plot_range(my_plot, data1.begin(), data1.end(), "Tigers", limegreen);

// write to file. NOTE: Will change to write(filename) soon
my_plot.write();

produces the following output:

​http://www.tcnj.edu/~voytko2/svg.htm

Using Boost.Array

Because Boost.Array supports an iterator-like interface, (my_arr.begin(), my_arr.end()), Boost.Array can freely be used with the program produces the following output:

To-Do List

For next week

• Create a more consistent internal name scheme (I'm starting to confuse myself)
• Accept generic STL containers, Boost.Array
• Begin to incorporate a key/legend into the graph
• Allow streams to be specified as output points
• Move files not to be consumed by users to "detail" folder

By July 2nd

• Expand workings of program to two dimensions

3. Suggestions (No ETA as of May 28)

By Matias Capeletto:

• Be able to choose a log scale for either the X or the Y axis
• Proposal to include a plugable extractor to plot_range()

In general, containers will store other things than double. Starting simple, I want to be able to plot std::vector<int>. This is very easy to support. Add a function:

template<class Iter, class DoubleExtractor >
plot& plot_range( Iter start, Iter end, DoubleExtractor double_extractor)
{
    return your_old_plot_range(
       boost::make_transform_iterator(start, double_extractor),
       boost::make_transform_iterator(end  , double_extractor)
    );
}

This have other implications, for example if we have list<Human> hl, and struct get_age_functor { ... }; We can:

plot_range(svg, hl.begin(), hl.end(), get_age_functor() ); // fun stuff :)

By Paul Bristow

• Customize background color of plot Completed
• Customize the background border color
• Customize the "axis area" background color
• Title
  • Customize font
  • Customize font color
• Axis
  • Customize line colors
  • Customize line thickness
  • Define labels for axis
  • Major ticks width, length, color
  • Minor ticks width, length, color
  • Reasonable defaults for ticks
  • Axis marker labels
  • Consider the axis for data where the origin is not in the view window
  • Consider auto-scaling
  • Grid lines
• Data representation
  • Allow different data representation points
  • Allow appropriate customization of data points
  • Consider labels for data points (combined with exploration of hover-text features of SVG mentioned above) Completed in legend
  • Consider how to concisely represent the scale of data points
  • Multiple data series Completed
• Legend
  • Border
  • color Partially Completed
  • position
  • border thickness
  • background colors Completed
• Unicode strings

4. Bugs D:

• Changing or setting the x_scale after calling my_graph.draw_axis() makes the axis not be drawn.
  • This is caused because I store points after setting the graph. I will fix this by storing infinity as +NaN in the point, and when outputting, writing it at a location far off the graph