A Brief Overview of Data Objects

In addition to simple plotting, Kst has the ability to do real time analysis of data using a number of “Data Objects”, which include spectra, equations, histograms, fits, and filters.

As a quick demo of Data Objects, lets create a spectrum. Start Kst and re-load mykstsession.kst that you created in previous sections. Then, from the Create menu select Power Spectrum. The New Power Spectrum menu will appear.

Fill out the dialog as shown. Make sure you select “Column 3 (V4)” as the Data vector, set the FFT length to “2^13”, Sample rate to “60” and select “In new tab” under Placement. Then select OK. A plot of the spectrum of “Column 3 (V4)” will appear in a new tab.

It is hard to see any details in this plot - a log-log plot would be much easier. To toggle the Y axis to log press l (that is, small L) and to toggle the X axis to log press g. (These options are also available in the context menu under the Zoom submenu in case you forget the keyboard commands). The plot will now be log-log, as shown:

Hitting l (small L) and g will toggle back to linear axis.

From the Create you can similarly create histograms, spectrograms and equations of fields you have loaded.