The Basics of Plot Manipulation

Now that you are comfortable with creating plots in Kst, we can explore some of the plot manipulation features available through the Kst graphical user interface. Start Kst and load the mykstsession.kst file you saved earlier. This can be done one of three ways:

All the plots you created earlier should now be loaded in Kst. Consider the plot of Column 1. To take a closer look at that plot, right click in it and select the Maximize menu item (see below). Notice that the menu item shows that Z is a shortcut for this, so you could also just type Z in the plot rather than using the context menu for this. Selecting Maximize (either with Z or with the menu) will cause the selected plot to fill the entire kst window.

Maximizing a plot
Maximizing a plot

Selecting Maximize (or typing Z in the plot) again will restore it the plots to their previous arrangement. This is especially valuable if you have a grid of many small plots and want to temporarily look at just one of them. Obviously typing Z is going to be the most convenient way to do this, but the context menu is there in case you forget.

In Kst, it is very easy to zoom and scroll the data, using either the mouse or the keyboard. To do this you should be in XY Zoom/Scroll mode, selected by selecting the icon in the tool bar. This is the default mode.

To zoom into a region of interest, left-click drag a box in the window with the mouse. When you release the mouse, the window will zoom in X and Y into the region you selected. Holding Shift when you do this will cause the plot to zoom only in Y. Holding Ctrl when you do this will cause the plot to zoom only in X.

Arrow keys scroll the plot. Arrow keys with Shift held down will change the scale. The M key auto-zooms the plots to view all of the data. Play around with these options to become familiar with the various options.

Now look at the plots with y axes labeled Column 2 and Column 3. These are plots of the pitch gyro and roll gyro, respectively, from an instrument. Since these two plots are related, it can be useful to zoom and scroll them simultaneously. Click on the circles located at the top right corners of the two plots. They should turn dark in color to indicate that the two plots are now tied together:

Tied Zoom

Now try zooming in with the mouse on a portion of the green curve in the middle plot. You will find that the lower plot will become blank. This is because the lower plot axes have changed to match the upper plot axes, and there is no data in that particular region of the lower plot. Type M while the mouse cursor is over either plot to return to maximum zoom on both plots. Now hold down Ctrl (this is equivalent to selecting X Mouse Zoom Mode from the Mode menu or clicking the toolbar button). If you then move the mouse, you will see that it is now dragging a vertical line the height of the plots in both of the plots that are tied together. While keeping Ctrl held down, drag a rectangle in the middle plot. While dragging, the region you are selecting will be displayed in both tied plots. Both plots will rescale to the region you have selected.

Tied Zoom

As with the mouse actions, the keyboard based zoom/scrolling actions described earlier will now be applied to both plots.


You can quickly tie or untie all the plots in the window by selecting Toggle Tied Zoom from the Mode menu or by clicking the toolbar button.

When you are finished experimenting with the zooming features, you can close Kst. There is no need to save the plots this time (unless you wish to).