Zeptoscope

This page will walk you through using some of the basic functions of Zeptoscope. If you don't have the program installed yet, install it from the download page. Then download a sample data file from here and save it somewhere on your computer.

Opening a file

Start Zeptoscope and open the data file by using the File menu or simply by dragging and dropping the file icon. You should see a signal selection dialog. Choose all of the signals, as shown below, and click OK.

signal selection dialog

Now you will see a plot of the selected signals. You can bring up the signal selection dialog again using the Plot menu or the shortcut key Ctrl-D.

plot

Zoom

Try zooming in using the mouse. Draw the zoom rectangle from the upper left corner while pressing the mouse key. A zoom rectangle is shown on the screenshot below. Autorange by moving the mouse in any other direction while pressing down the key. You can also zoom in and out on either axis or both axes using the commands on the plot menu, as well as shortcut keys.

zoom rectangle

Pan

Hold down the right mouse key and drag the plot (use the mouse button with the Control key on a Mac), or use the Plot pull-down menu and go to Pan submenu. Finally, you can use the shortcut keys for fine and coarse panning, which are listed next to the commands in the Pan submenu. Using the shortcut keys is usually the most convenient way to pan the plot, and in some cases to scale it as well.

panning panning shortcuts

Markers

Double-click on a trace and you will see a thin red crosshair. This is marker zero. Above the plot you will see a red cross symbol and in parentheses next to it the values of the x and y coordinates of the marker. Now click once on the same trace. This time a blue crosshair should appear. This is marker one. A small blue cross symbol will appear above the plot, and to the right of it there will be some information about the selected range of data: x and y delta values, y ratio, ratio of delta values, mean y value in the selected range, ordinary linear regression slope and standard deviation of residuals, and number of points.

values markers

If you right-click on a plot without moving the mouse, a context menu will appear, with a Marker submenu, where useful shortcuts are listed.

markers

In this case the standard deviation of residuals Sy.x is approximately the RMS noise value. Essentially, this statistic is a measure of noise around the trend line. The blue marker may actually be placed on a different trace. In that case, there will be less information about the selection: no mean y and no regression statistics, and, if the y-units of the two traces are different, there will be just the delta x value.

Panels

Download the second data file example from here. It is similar to the first one except that one of the signals has different units of measurement. Open the second example. You will see that the plot is now split into two panels, which share the horizontal axis. The horizontal zoom and pan are coupled, and vertical, independent. The split-panel mode is optional. It is controlled by the plot settings, which are discussed in detail in the next section.

panels

Plot settings

Many things about the plot's appearance are determined by the settings XML file. Although this page is called "getting started", this feature is for advanced users. However, we hope that it is easy to learn. By using it, you can customize the plots and automate the way they are generated, which can save a lot of time. If you are satisfied with the default appearance of the plots, simply skip this section. Knowledge of XML or some programming experience will help but is not required.

The following are the most important functions of plot settings:

  • Title and subtitles can be generated automatically from metadata contained in the file header.
  • Trace settings are assigned according to signal names. Multiple names per trace type and regular expressions (more on that below) are supported, i.e. it is possible to write simple generic rules. Trace settings determine trace and symbol type and color, symbol size, and panel. All of these attributes are optional.
  • Similarly, axis settings are assigned according to units of measurement. Axis settings determine axis color, panel assignment and, if you are not satisfied with autorange, the default range.

When Zeptoscope is first installed, it uses the default settings file, which you can export through the File menu. You can always switch back to the default settings by selecting "Restore defaults" from the File menu.

Try downloading this modified settings file and importing it (also through the File menu, of course). The open plots will be redrawn using the new settings. Below is the plot of the second data file example with the modified plot settings. This plot has a different title and no subtitle (the title can also be changed in the plot properties under the Edit menu, but here we are more interested in the automatic generation); the color assignments are different, the second panel is gone, and of course one of the signals uses symbols instead of a trace line; you may also notice that the range of the A axis is different.

panels

If you compare the default and the modified settings files, you may also notice that the modified version uses a regular expression to match "noise signal 3". In this case, it works the same as a simple wild card that matches the word "noise". Another, more complicated regular expression is used in both the default and the modified settings to match various pressure units. If you are not familiar with regular expressions and are curious, you can find a lot of information about them on the web. However, it is not necessary to use them for Zeptoscope. Without regular expressions, your settings may be more verbose, but everything will still work.

Multiple settings files may be created for different types of data and loaded as needed, but, in our opinion, even for many different types, it's best to try to define all the rules in one or two files.

Although the settings have rules defined for all the signal names and units of measurement that are used in these examples, of course the program will work with any signal names; if there is no match, it will use the default list of trace types and colors.

For editing the settings files, we recommend using an XML editor with syntax highlighting, autocompletion and error checking. When you open a settings file, it should download the schema automatically from this website and be aware of Zeptoscope plot settings syntax. One such editor is jEdit, which is an open-source cross-paltform programmer's text editor. When you install jEdit, add the XML editor plugin through the Plugins menu.


This is a good place to end the introduction. We have already touched on some of the more advanced features. We will try to add a separate section with more details about these features, and cover the ones that were not covered here.