Walking Randomly

This is the second post in a series. The third post is at https://www.walkingrandomly.com/?p=3512

DataAnalysis – free curve fitting on iPad

DataAnalysis is a fantastic curve fitting and plotting package written by Evan Kantrowitz.  You can import your data (in .csv format) from a variety of sources including email, iTunes and Dropbox.  Once imported, DataAnalysis allows you to modify your data if necessary and then plot it in a variety of styles before fitting it to one of several different regression models.

There is a nice range of built in model types including polynomial (currently only up to order 3), power, exponential, gaussian and more with the full list detailed over at the DataAnalysis website.  New model-types are being added all the time and the developer is willing to consider specific requests. Fitting is performed in the least-squares sense and the user can choose which numerical algorithm to use – Newton or Levenberg-Marquardt.  My only gripe here is that it is not possible to define your own fit function so if the model you want to fit your data to has not been included then you are stuck.

Once you have completed plotting and fitting your data, you can export the whole thing in either .png or .pdf format via email, Dropbox or to the iPad Photos app.  Alternatively, you can copy the graph to the iPad clipboard for inclusion in other apps.

This is a fantastic app that delivers exactly what it promises at a price that’s impossible to beat.