3. Usage

WASP provides an user-friendly Graphical User Interface (GUI) which makes it quite easy to use. In this user's guide we show how to work with WASP (version 1.2) using GUI.

3.1 Graphical User Interface

Fig.: Main Window

Click the Open item in the File pop-up menu to choose input data file. The Reopen item in this menu allows one to open the same file again (e.g., when the end-of-file is reached). Note, that the implementation of the WASP implies the following input file format. The file is read line-by-line. If the line contains at least two numbers, the first of them is interpreted as a polar angle in radians, the second one -- as azimuthal angle in radians (moreover, it is transformed to be in if necessary), the rest of the line is ignored. Other lines are interpreted as event separators.

Use Next, Prev, Next 10, Prev 10 buttons on the left-hand panel of the main window to get the needed event from file (these functions are duplicated as items of the Tools menu, moreover, there is an All item in it which allows one to collect events from a data file). One can use event selection feature tuning it by clicking the Filter item in the Options menu to skip events that do not satisfy the chosen settings. Event selection dialog is shown on Fig. .

One can choose the raw event representation by clicking Picture button on the main window left-hand panel and the wavelet spectrum representation -- by clicking Picture button on the right-hand one. Instead of clicking Picture buttons one can choose corresponding items in the Options menu. Corresponding panels are shown on Figs. a and b.

Fig.: Event Selection Dialog

Fig.: Event (a) and Wavelet Spectrum (b) Representation Dialog

a) b)

The default event representation is pseudorapidity distribution. The histogram ranges are calculated automatically over each event. They can be fixed by hand using the panel shown on Fig. a instead, moreover, a histogram title, x-axis and y-axis labels can be chosen (Fig.  shows defaults). Note, that the x-range fixed for one-dimensional histograms does not affect on the obtained wavelet spectrum, since it is built over the whole sample directly (without histograming). It is just a zoom feature. The y-range fixing option is not used for one-dimensional histograms. On the contrary, the two-dimensional wavelet analysis takes into account the histogram with its ranges, calculated automatically or fixed by hand.

The default one-dimensional wavelet used for transformation is the second derivative of the Gauss function (``Mexican Hat''). The x-range and the x-axis label are the same as for the raw event histogram. The default scale-range is from 0 to 1/3 x-range. It can be fixed manually using the panel shown on Fig. b instead, moreover, a wavelet spectrum title and scale-axis labels can be chosen (Fig.  shows defaults).

Fig.: Image Filtering. Five levels of decomposition are used here. Wavelet coefficients of the first four levels (``high frequencies'') are nullified before reconstruction.

The Slice/Filt button has two functions. First, it allows one to view the wavelet transform of one-dimensional signal at a chosen scale parameter (the last one is set by a slider and controlled by a text entry). The corresponding view shown in [3] is omitted here. Second, it allows one to view the filtered image of a two-dimensional signal using discretized wavelet transform (see Fig. ).

The Energy button allows one to draw wavelet energy spectrum: (where is a scale parameter, is a number for one-dimensional signals and a two-dimensional vector for two-dimensional ones). The Scalogram button gives a scalogram: .

The Wavelet button allows one to draw wavelet spectrum with a better resolution or just redraw it (after Slice/Filt or Energy buttons are pressed, e.g.)

Fig.: Application of the 2D ``Mexican Hat'' wavelet. The view of the wavelet transform of a two-dimensional signal at a chosen scale parameter (the latter is set by slider).

The two-dimensional ``Mexican Hat'' function is used in WASP for the wavelet transformation of two-dimensional signals (see above). This transformation is performed after the Wavelet button is pushed (see Fig. ).

Both Save buttons are used for saving corresponding images to EPS-files: file ``en_r.eps'' for raw event image and file ``wsn_r.eps'' for wavelet spectrum, where n is an event number in data file, r is an event representation number according to the panel on Fig. a.

The Dump button is used to save a wavelet spectrum matrix to the ASCII file (the x-axis grid is written first, then the y-axis one , and finally corresponding wavelet coefficients, line-by-line, from the minimum of y to the maximum). The file ``wcmn_r.dat'' is created when the Dump button is pressed (n and r have the same meaning as above).