Signal Handling

Loading and Saving Signals
Signal Types
The Signal Iconbar
Displaying Signals

Loading and Saving Signals

Signal data files can be loaded in either of the following ways:

• Click on the icon in the command toolbar.
• Select Load signal from the File menu.
• Drag and Drop.
• Click with the right mouse button on the signal iconbar.

In both cases a file selection dialog box with the title "Load a signal file'' is brought up that asks you to specify a file. Click OK to load the selected file and close the dialog box or Cancel to quit the file selection box without loading a file.
You can load several or all signal data files contained in a directory using Load signals from the File menu. Specify a directory in the dialog box that appears. If you click OK a window showing an alphabetical list of all files in the directory is invoked. All files in the list are preselected, i.e. they appear on a blue background, and will be loaded if you confirm. To unselect those you do not want to load click on the filename which then will appear on a white background.
For loading signal data Dataplore ® supports the following file formats:

.dpa:

Dataplore ® ASCII file format. Files with the extension .san also contain data in Dataplore ® ASCII format. They are obsolete but can still be read by Dataplore ®.

.dpb:

Dataplore ® binary file format. Files with the extension .sbf also contain data in Dataplore ® binary format. They are obsolete but can still be read by Dataplore ®.

.mw:

MegaWave II format.

.wav:

WAVE audio file format.

.au:

Sun audio file format (not implemented yet).

.??? (any other extension):

raw ASCII data without header information.

If you choose ASCII data to be loaded as a signal, (e.g. a *.txt file), an ASCII import dialog will pop up, giving you the following options :
Separate channel by Tab, Space, Comma, Semicolon or Other. The idea is that your ASCII data may be organized in one or more columns, each being the input of a "channel''.
The Decimal character can be set to Point or Comma.
Signal type can be one of the following:

• Channel, this is a one-dimensional ("normal'') signal with one or more channels,
• IBI (Inter Beat Intervals),
• Plot, to create a plot signal from your file, assuming the data are the 2 or 3-dimensional coordinates of the points to be set. (There have to be 2 or 3 columns, respectively.)
• Grid, to create a two-dimensional signal defined on a regular 2D grid.

You can save a signal to the hard disk in either of two ways:

• Click on the icon in the command toolbar.
• Choose Save signal from the File menu.
• Click with the right mouse button on the signal iconbar.

A file selection box with the title "Save a signal file'' appears. Enter a filename and click OK to store the signal data under this name or click Cancel to quit the selection dialog box without saving the signal.

Signal Types

Dataplore ® distinguishes between the following signal types:

Standard:

a one-dimensional signal with only one channel containing equidistantly sampled data.

Complex:

a one-dimensional signal with two channels, the first one being the real part and the second being the imaginary part.

Multi-channel:

a one-dimensional signal with several channels having the same number of sample points, sampling rate, shift, and units. The maximum number of channels is 128.

IBI:

Inter Beat Intervals. IBI signal data contain the (time) intervals between the peaks of a standard signal. You can convert a standard signal into an IBI signal using Convert/Signal to IBI from the Basic menu.

XY(Z) Plot:

2D or 3D plot signal containing a list of points (2D or 3D coordinates) in the 2D or 3D space (not necessarily equidistant).

2D Signal:

a two-dimensional signal defined on a regular 2D grid, i.e. one z-value for each sample location (xi,yi) on the 2D grid, where the (xi,yi) are lying equidistantly on a rectangular two-dimensional area.

DWT:

discrete wavelet transform type; the result type of Decompose (discrete wavelet transform).

CWT:

continuous wavelet transform type; the result type of a Continuous wavelet transform.

WPD:

wavelet packet decomposition type; the result type of a Wavelet packet decomposition.

Within the Dataplore ® macro language, the signal types are accessed by their symbolic names:

signal type	internal name
Standard	SIG_TYPE_STD
2D Signal	SIG_TYPE_2D
Multi-channel	SIG_TYPE_CHANNEL
Complex	SIG_TYPE_COMPLEX
IBI	SIG_TYPE_IBI
2D contour plot (obsolete)	SIG_TYPE_CONTOUR
XY(Z) Plot	SIG_TYPE_PLOT
CWT	SIG_TYPE_CWT
WPD	SIG_TYPE_WPD
DWT	SIG_TYPE_DWT

The Signal Iconbar

Each signal object either loaded from disk or being the result of an operation within Dataplore ® is represented by an icon on the signal iconbar. For every signal type there is a corresponding icon style.

A typical iconbar looks like the following:

signal type Standard.

signal type Complex.

signal type Multi-channel

signal type IBI.

signal type Plot.

signal type 2D signal.

signal types DWT and CWT.

signal type WPD.

You can access a signal object via the corresponding icon.
If you move the mouse pointer on a signal icon, the signal's selection number (see below), filename (if loaded from disk), title, size, and dimension are shown in the left part of the statusbar at the bottom of the Dataplore ® main window.
Almost all of Dataplore ®'s functions require a certain number of input signals. The corresponding signals must be selected by clicking on their icon. To unselect a signal click a second time on its icon.
A number is given to every selected signal, its selection number. This number corresponds to the order of selection. Thus the signal selected first receives the number 1, the second 2, ... If a selected signal is unselected or removed from Dataplore ® the selection numbers of other signals are changed correspondingly. The signal selection number is useful because the result of almost all functions requiring more than one input signal depends on their order.
If the number of selected signals as input to a function is wrong, a dialogbox showing a list of all signals will appear. You can change the number and order of the input signals and start the function by confirming your selection (OK). From the General panel on the preferences dialog (invoked from Preferences... in the Options menu) you can choose when to invoke this "signal input dialog" by setting one of the three alternatives

• Always, i.e. every time a signal is required as input to a function
• Only if number of inputs incorrect, if more or less input signals than required are selected.
• If number of required inputs > 1, if the function requires more than one input signal.

Signal Icon Context Menu

The signal icon context menu appears after a right mouse click on a signal icon. The items in this menu refer to this signal (except the two items refering to all selected signals).

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The signal icon pop-up menu.

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Open window:

brings up a window displaying the signal graph. The signal graph can also be displayed with a double click on the signal icon.

Open window with selected:

brings up a window displaying the graphs of all selected signals in a common coordinate system. Only Standard, Complex, and Multi-channel signals are allowed.

Play sound signal:

performs an internal conversion of the signal to the WAVE format (standard extension .wav) and plays it. Warning: The WAVE format supports only sample rates of 11.025 Hz, 22.050 Hz and 44.100 Hz. If the signal's sample rate does not match one of these three, the nearest will be taken instead and the user will be asked for the specifications of the sound format in a dialog box.

Delete signal:

removes the signal from Dataplore ®. Its icon disappears from the signal iconbar.

Delete all signals:

removes all signals from Dataplore ®. The icons disappear from the signal iconbar.

Delete selected signals:

removes all selected signals. A listbox appears allowing you to check the selection and change it, if necessary. When you confirm the selected signals are removed from Dataplore ® and the corresponding icons disappear from the signal iconbar.

Load signals:

loads a signals file (extension .dps) previously saved with Dataplore ® and adds the respective signal icons to the signal iconbar.

Save selected signals:

saves all selected signals to a .dps or .dpa file.

Save signals:

saves all signals in the iconbar to a .dps file.

Displaying Signals

The Dataplore ® Signal Display Windows

For every signal type Dataplore ® offers corresponding display methods to visualize and present it:

• Signal plots for the signal types Standard, Complex, Multi-channel, and IBI. Figure 1.10: Multi-channel signal
• Isoline (contour) and surface plots for the signal type 2D signal. Figure 1.11: Surface plot.
• Wavelet decomposition displays for the signal types DWT, CWT, and WPD. Figure 1.12: Continuous wavelet transform (density style).
• 2D and 3D delay and phase plots for the signal type XY(Z) Plot. Figure 1.13: 3D delay plot.

To display a signal invoke the signal icon context menu and choose Open window. A window appears showing a plot of the signal. The style of the plot corresponds to the signal type.
Under Linux/Unix you can use drag-and-drop to display a signal in the Dataplore ® main window: Move the mouse pointer onto the signal icon, hold the left button down and drag the signal into main windows display area. If you release the mouse button the signal plot is shown. If the main window is splitted you can drag and drop one signal into the upper and one into the lower part. By holding down the 'Control' key while dragging and dropping a signal into one of the main windows you can easily add the selected signal to the signal displayed in that window. Note that the x/y area of the first signal in that window will be kept unless Capture min and max in the Area options is de-activated. If you want to add a signal to another window but the main window under Linux/Unix as described above, you will have to drop the icon at a position in the respective window that does not overlap with the main window since there is no other possibility to decide which window is the active one.

Dataplore ® offers various ways to display more than one signal in the same window:

• Select the signals by clicking on their icon and then choose Open window with selected from the signal icon context menu. They will be plotted in a common axes system using a different colour for each signal. Only signals of the types standard, complex, and multi-channel can be used.
• Select Open signal window from the View menu to open a signal display window showing a plot of the selected signals within the same coordinate system. A different colour is used for each signal.
  If no signal is selected, a dialog box appears allowing you to select from a list of signals.
  Only signals of the types standard, complex, and multi-channel can be used as well as single or multiple XY-plots.
• Choose Open multiple signal window from the View menu to open a display window showing separate plots of all selected signals.
  The signals may have different types.
• Open tag signal window opens up a display window showing the selected signals on the left hand side and their y-values at the current x-position that can be changed by sliding along the signal with the middle mouse button held pressed or by using the PgUp and PgDown keys for pointwise movement.
  This kind of window can be applied to standard, complex and multi-channel signals. Note that the signals must be of equal scale and shift.
• Use Open scroll window from the View menu to open a display window showing one twentieth of each dimension of the selected signals in a separate axes system. Two scroll bars are at the bottom of the window. The left one allows you to scroll along the time-axis. The right one can be used to reduce or to enlarge the interval displayed (from the complete signal to one fiftieth).
  Only standard, complex, and multi-channel signals can be displayed this way.

You can create a hardcopy of the contents of any Dataplore display window by selecting Print from the File menu or by clicking on the icon on the command toolbar.

Annotation, Positioning, and Zooming Mode

You can work on the contents of a signal display window in one of the three following modes:

Annotation mode

allows you to create text areas for annotations in a signal plot. Place the mouse pointer on the signal display, hold the left button down and move the mouse. A rectangle surrounded by a dashed line is raised. Release the mouse button if the area defined this way has the desired size.
The text area can be moved within the display window: Place the mouse pointer on it, hold the left mouse button down and move the mouse. Shift the text area to its new location and release the mouse button.
To resize the text area, place the mouse pointer on one of the borders, where it will turn into a double arrow. You can then shift the border by holding the left mouse button down.
To enter text double-click on the text area. A text editor appears allowing you to enter the annotation text. Click OK to quit the editor and to display the text.

Positioning mode

allows you to move a signal plot to a new position within the display window. Move the mouse pointer into the window and press the left button. The signal plot will appear surrounded by a broken line. You can then move the plot by holding the mouse button down and shift it to the desired place.
To resize a signal plot, place the mouse pointer on one of the borders, where it will turn into a double arrow. You can then shift the border by holding the left mouse button down.

Zooming mode

allows you to zoom into a signal plot. By holding down the left mouse button you can specify an arbitrary rectangle for defining a region of interest. Release the mouse button to zoom in. You can repeat this procedure several times.
Press the 'ESC' key to get the previous view. At any time the full signal display (default) can be requested by a click with the middle mouse button or a double click with the left mouse button.
To view another interval of the signal use the right arrow key or the left arrow key from your keyboard to scroll along the x-axis in the corresponding direction.

Signal Window Context Menu

By moving the mouse pointer onto the display window or a signal window a signal window context pop-up menu can be invoked by a right mouse button click.

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The signal window pop-up menu.

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Child settings ...:

brings up a the child settings dialog allowing you to change the display attributes such as

• the general appearance (colour, line style, line width, ...)
• the canvas style
• axis properties (scaling, colour, units, ...)
• titles and keys
• annotation text
• colour map selection for 2D grid plots

The Options menu section contains a more detailed description of its possibilities.

Add zoom marker:

adds a zoom marker at the current x-position of the mouse pointer within the window. The appearance of the zoom markers can be changed in the Child Settings menu.

Zoom to marker:

zooms into the area between two zoom markers.

Del zoom marker:

deletes the zoom marker below or near the current mouse pointer position.

Cut out signal:

creates a new signal by cutting out the signal segment currently displayed (see also Cut out)

Clip signal:

creates a new signal by clipping y-axis values outside the range currently displayed (see also Clip)

Reset:

resets the signal window to its original size and position and places the signal title at the position specified in Child settings.