Chapter 4. A Quick Tour of the Data Wizard

While using KST from the command-line is fast and convenient, there may be situations in which it is easier to import data from the graphical user interfacefor example, if you already have KST open with other data loaded. Or, you may simply prefer using the graphical user interface. Becoming familiar with both methods of importing data will allow you to make more efficient use of KST.

The Data Wizard provides a quick and easy way of creating vectors, curves, and plots in KST from data files. To launch the wizard, select Data Wizard... from the Data menu or click the button on the toolbar. You will be prompted to select a data source. Browse to the gyrodata.dat file used in the command-line examples and click Next. The following window will be displayed.

Data Wizard Screen 2

The fields available in gyrodata.dat are listed to the left. You may filter the list of highlighted fields by entering a string to match (wildcards such as * are supported) into the text box above the list. Enter * to match anything (i.e. highlight all the available fields), and then click Check Selected to select all the highlighted fields (which in this case happens to be all the fields).

The Data Range section is used to specify the range of data to read from the selected vectors in the input file. The following discussion assumes knowledge of frames. In brief, a frame is simply a number of data samples, and each data file is composed of a number of frames. For a detailed description of this concept, see the Kst Handbook.

Starting frame, Count from end, Number of frames, and Read to end

Using these four settings, the lower and upper boundaries of the data range can be set. As an example, select Count from end and enter 10000 for Number of frames to read only the last 10000 frames. If gyrodata.dat was being updated in real-time, subsequent additions to the end of the file would be read.

Read 1 sample per N frames and Boxcar filter first

In addition to the lower and upper range boundaries, the samples to read from the selected range can be set. If Read 1 sample per N frames (where N is the entered value) is not selected, all samples in the selected range will be read. Alternatively, frames in the data file can be skipped by selecting Read 1 sample per N frames For now, deselect Read 1 sample per N frames.

Power Spectrum and X axis settings can be specified within the Plot Types section.

XY, Power Spectrum, and XY and Power Spectrum

Select XY and Power Spectrum to produce plots of both the data itself and its power spectrum.

X Axis Vector

The vector to be used as the independent vector for the plots. You may select a field from your data file, or the INDEX vector. Since gyrodata.dat does not contain an X axis vector, leave the selection as INDEX.

The FFT Options subsection in the Plot Types section is available only if a power spectrum is to be plotted. This tutorial will not deal with the details of power spectra, so use the default settings for this subsection.

Once you are satisfied with all the settings, click Next to advance to the next window.

Data Wizard Screen 3

From here, you can change general plotting settings. Most of the settings are self-explanatory. Select 1 new plot per curve for Curve Placement and In new window for Plot Placement. This will place all six plots (three curves and three power spectra) in the same window.

Once you are satisfied with all the settings, click Finish and the plots will be generated:

The Generated Plots

Generating these plots took a bit of effort, so we should save the current KST session (it will be used in the next section of this tutorial). Select Save As... from the File menu, and save the session as mykstsession.kst:

Saving a KST session

Saving a KST session saves all the plots, data objects (you will learn about these later), and layouts that exist at the time of saving.

Once the file has been saved, you can exit KST.