SOFA Statistics (http://www.sofastatistics.com) is an open source desktop Python statistics application with an emphasis on ease of use, learn as you go, and attractive output. This presentation covers the lead developer's experiences with some of the technical aspects of the project as well as project management issues.

1. SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand SOFA Statistics Developing and releasing a Python open source application Grant Paton-Simpson sofastatistics.com

3. How SOFA works with SQL databases

4. Using HTML for output (via wxWebKit)

5. Experience with existing statistics modules

6. wxPython GUI toolkit (esp the grid widget)

7. The release process (esp packaging)

8. In 30 minutes flat out!

11. Producing charts

13. May be useful for specialist statisticians but emphasis on supporting non-specialists, and learning statisticians

14. Currently version 0.8.10 and pushing on towards a version 1.0 release

15. SOFA Architecture ... Linking not importing SQLite MySQL MS Access PostgreSQL SQL Server SOFA Scripts from GUI or by hand (available for automation) HTML output (spreadsheet- friendly)

17. Want control over the information I get about data configuration (e.g character set)

20. PostgreSQL and SUM(expression)

22. Created an artificial limit of 5000 cells

23. Scales linearly and Python not the bottleneck

24. Rendered locally using wxWebKit

27. Less risk (the results of statistical algorithms can wildly diverge because of small floating point errors compounding and multiplying)

29. No option of using decimal instead of floating point maths

30. Half-baked code in some places

33. NB still lots more functionality to be added

34. Switch over to Jaunty

37. Mac OS X package, more flexible packaging

38. Add ability to import from Calc and SPSS

39. Other databases e.g. Oracle, DB2, Interbase

40. Increase test coverage SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Plans

42. ROC, power calculations

44. May be useful for specialist statisticians but emphasis on supporting non-specialists, and learning statisticians

45. Focus on making most common needs easy to satisfy

46. Plugin extensions for rest SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Plans cont ...

49. Mailing list (with Robin Dunn a regular contributor)

50. Lots of online documentation (but googling and integration of different ideas often required)

52. Can reuse code across different forms

55. Only 1100 lines of code to make the data grid you saw in the demonstration (inc validation, ability to add new rows and edit values etc)

56. May be sensible to have more lines of documentation than code in some modules

58. Found out Windows intercepted Tabs and Returns before they could be exposed and reacted to

59. But there was a solution SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand wx.Grid

60. SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Example of wx.Grid code self.frame.Bind(wx.grid.EVT_GRID_EDITOR_CREATED, self.OnGridEditorCreated) … def OnGridEditorCreated(self, event): """ Need to bind KeyDown to the control itself e.g. a choice control. wx.WANTS_CHARS makes it work. """ control = event.GetControl() control.WindowStyle |= wx.WANTS_CHARS control.Bind(wx.EVT_KEY_DOWN, self.OnGridKeyDown) event.Skip() … def OnGridKeyDown(self, event): keycode = event.GetKeyCode() if keycode in (wx.WXK_TAB, wx.WXK_RETURN): etc The user clicks on a cell to edit a value. We bind to that event. Now we can grab the control ... … and respond to its key down event Now we're away again :-)

61. SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Custom Controls

63. Conditional formatting e.g. all values > 1000 red

67. Make sure I have translations for any new strings I've added.

68. Make and test the new deb and Windows packages. I use VirtualBox to give me identical install environments each time.

69. Add the new files to Sourceforge (I wanted to consolidate downloads to help me measure usage).

70. Add a new release to Launchpad and Freshmeat complete with updated release notes and change log (used Bazaar to push to Launchpad so can browse my commit comments).

71. Make announcements in both Launchpad and Freshmeat.

72. Update the project homepage to account for the new download location, new features.

73. Add a blog item to the project site.

74. Update release version and release date on Wikipedia.

75. Revisit any important threads commenting on open source statistics packages. SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Release process

79. Any files needed by an individual user are transferred during first use of application /home/username/sofa/... SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Making Debian Package (for Ubuntu)

81. Weird language – cross between PHP and assembler

82. Plenty of documentation etc but best to start and then extend

83. Issue – file size. Including mysqldb, numpy, wxpython, sqlite, python

84. Put program in Program Files and user files in Documents and Settingssernameofa.. SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand NSIS Windows Installer

86. Lots of new learning

87. A long-term commitment

88. Lots to do. Not just glamour coding - someone has to “take out the trash”

89. Phenomenal resources available in open source world – bazaar, loggerhead, nosetests, etc

90. Hands up if ever considered it (or doing it) SOFA Paton-Simpson & Associates Ltd Auckland, New Zealand Final Thoughts