Archive for January, 2017

Great new SOFA teaching resource

Saturday, January 28th, 2017

Thanks to George Self there is a great new teaching resource available for SOFA users. See https://goo.gl/4lpIaO Here is George’s announcement repeated from the discussion group:

I teach an undergrad research methodology class and wrote a SOFA-based lab manual for that class that some of you may be interested in. You can find the manual and the data sets at https://goo.gl/4lpIaO.

The manual has ten chapters:

  1. Introduction (data types, normal distribution, kurtosis, skew, null hypothesis, downloading/installing SOFA, recoding data)
  2. Central Measures (mean, median, mode)
  3. Data Dispersion (range, quartiles, standard deviation)
  4. Visualizing Dispersion (box charts)
  5. Frequency Tables (frequency tables, crosstabs, complex crosstabs)
  6. Visualizing Frequency (histogram, bar chart, clustered bar chart, pie chart, line graph)
  7. Correlation (pearson’s r, spearman’s rho, significance, scatter plots)
  8. Regression
  9. Hypothesis Testing: Nonparametric Statistics (SOFA Statistics Wizard, Kruskal-Wallis H, Wilcoxon Signed Ranks, Mann-Whitney U)
  10. Hypothesis Testing: Parametric Statistics (ANOVA, t-test-Independent, t-test-Paired)

There are also two appendices, the first is a data dictionary for each of the data sets used and the second covers the various report generating features of SOFA.

The lab manual covers all of the functions and features of SOFA, but in the context of a lab where those functions are practiced rather than just described. The manual also includes a lot of information about how the various statistical measures are used (for example, the difference between correlation and causation). No math knowledge beyond simple high school algebra is assumed on the part of the student and each of the labs includes a “deliverable” activity so instructors can use this as part of a class.

I’ve printed this manual under Creative Commons-BY-ShareAlike so please feel free to use this in any way you want. Of course, I’m also happy to receive comments that could help me improve this manual in the future.

–George

Please give the resource a spin and provide George with any feedback that can improve/refine it. Once again, thanks George for making this available to the community 🙂

SOFA passes quarter-million downloads

Friday, January 27th, 2017

I was delighted when SOFA passed 30 downloads in 2009 and here we are in 2017 more than 250,000 downloads later – still can’t believe it :-). Even though Sourceforge seems to have become confused about how many downloads there are having “lost” a whole lot in the last couple of months I am pretty confident we really have crossed the quarter-million mark. BTW a major new version of SOFA is in the pipeline and will be released when I fix some Mac installer problems.

Installing SOFA on Ubuntu 16.04 and 16.10

Friday, January 27th, 2017

tl;dr

echo "deb http://archive.ubuntu.com/ubuntu wily main universe" | sudo tee /etc/apt/sources.list.d/wily-copies.list

sudo apt update
sudo apt install python-wxgtk2.8
sudo rm /etc/apt/sources.list.d/wily-copies.list
sudo apt update
Download latest deb from http://www.sofastatistics.com/downloads.php
cd ~/Downloads
sudo dpkg -i sofastats-1.4.6-1_all.deb

Details

Even though SOFA is developed on Ubuntu (16.10 at present) there was a problem installing SOFA onto 16.04 or 16.10. The root cause related to Ubuntu support for different versions of wxPython and I spent a lot of time trying different solutions. Fortunately there is a simple workaround that only requires about six terminal commands (see below). Obviously, having to run commands is not as good as a standard installation but it will have to do for now because the main alternatives aren’t currently viable. E.g. some parts of SOFA don’t seem to play nicely with the packaged versions of wxPython 3.0. Snap packaging holds some promise but that will have to wait for later depending on the next releases of Ubuntu.

Thanks to bbobbo for finding a general solution to wxPython 2.8 installation problems on Ubuntu 16 and relating them to the specific SOFA problem and Domenico Somma for bringing it to my attention via the SOFA forum. Here are the steps (Solution from SOFA (statistics) – python 2.8 request – unable installation):

1. Add needed repository and update package list

echo "deb http://archive.ubuntu.com/ubuntu wily main universe" | sudo tee /etc/apt/sources.list.d/wily-copies.list

sudo apt update

2. Install it
sudo apt install python-wxgtk2.8

3. Remove repository entry and update package list again
sudo rm /etc/apt/sources.list.d/wily-copies.list

sudo apt update

4. Install SOFA Statistics
Download latest deb from http://www.sofastatistics.com/downloads.php

cd ~/Downloads

sudo dpkg -i sofastats-1.4.6-1_all.deb

5. Success?
sofastats

Extra info – Warning from http://askubuntu.com/questions/789302/install-python-wxgtk2-8-on-ubuntu-16-04 – “Following this method on large scale can lead to unmet dependency hell. So keep in mind this is similar to PPA’s.” This comment also has more details too about solving issues with broken packages.