3.3.13 Calculating the inverse Laplace transform spectrum

In the Spectrum folder there is a list of the numerical routines to be used for the Laplace transform inversion. Any or all of them can be chosen. If the Current option button is chosen in the Send data frame then the data currently displayed on the Main Graph with the name shown in the Current data frame will be sent. If the Previous option button is chosen then the files chosen from the top right-hand side list will be calculated. The Find uncalculated button helps to find all data files in the current data path for which there is no spectrum file in the current data path. The search is performed among the data files which names fit to the Pattern. When the files from the disk are sent for calculations (Previous data) and the Fixed starting point choice is active (the Customise form, and the Configuration menu) then for all files this preset number of points from the transient beginning are taken away.

 

The calculation process is initiated by pressing the Send button either on the Spectrum folder or on the Main toolbar. The calculations can be performed synchronously with the main application. It means that the main application showing the hourglass mouse pointer waits until the numerical procedure is over. The calculations are performed synchronously when the While-U-Wait check box is checked or corresponding button on the Main toolbar pressed. NOTE: depending on the number of the signal samples, the points on the spectrum, and the processor speed the calculations in some cases can take up to several minutes. When the calculations are completed the spectrum appears on the main graph. If the calculations are completed successfully the spectrum will be automatically saved on the disk and recorded by the Data base provided the Auto save box is checked. This spectrum can be also saved by pressing the corresponding button on the Main toolbar. For synchronous calculations only the current data can be sent (i.e. the Send data: previous option is disabled).

 

Performing numerical calculation in an asynchronous way (the While-U-Wait check box is unchecked) means that the main application creates input files for the calculations on the disk and passes them to another application (Calculation Dispatcher program RExeTris), which controls the queue of files waiting to be processed. This application is opened when the first data file is sent for calculation, and shuts down when the queue is empty AND the main application is not running. The Calculation queue is displayed in the Spectrum folder and is updated every 1 second when this folder is visible. The data files which have the status OK can be retrieved from the queue (using the Retrieve button), i.e. the corresponding spectrum file is created and registered (stored) in the Data base. All files, for which the calculations have completed successfully, can be retrieved automatically provided this action is enabled on the Customise form (default option). The Queue toolbar also allows the given (highlighted) file to be promoted and demoted in the file list. This action, however, cannot be performed for the file being processed. IMPORTANT: the first file which is processed is the one at the top of the list of files having the Waiting status. The Time label shows when the files having Waiting status were sent for processing and in the case of files having OK status the duration of calculations. The Points label shows the number of points on the spectrum. The time and the number of points are shown for the highlighted file on the list.