Geopsy: Correlations - Revision history

Clotaire Michel: /* Parameters */

2010-03-12T13:53:14Z

Parameters

Pierre-Yves Bard: /* Use of correlation */

2010-03-12T09:56:39Z

Use of correlation

Pierre-Yves Bard: /* Parameters */

2010-03-12T09:51:13Z

Parameters

Clotaire Michel: /* Parameters */

2010-03-11T14:55:12Z

Parameters

Clotaire Michel: New page: Correlations pop-up window '''Correlations''', reached from the Waveform menu, computes the correlations of the sign...

2010-03-11T13:39:57Z

New page: thumb|right|200px|Correlations pop-up window '''Correlations''', reached from the Waveform menu, computes the correlations of the sign...

New page

[[Image:Correlations.png|thumb|right|200px|Correlations pop-up window]]

'''Correlations''', reached from the [[Geopsy: Waveform Menu|Waveform menu]], computes the correlations of the signals in the active [[Geopsy: Signal Viewer|signal viewer]] with the requested signals.

==Parameters==
By clicking on ''Correlations'', a pop-up window appears with the following options:
*''Maximum time delay'' controls the size of the output window. The value m is in seconds. The correlations are displayed between -m and +m.
*Choice of the signal to correlate with the active signals. The possibilities are:
**''Between all pairs of signals'' will compute all the parts of the correlation matrix, i.e. the correlation of each signal of the active [[Geopsy: Signal Viewer|signal viewer]] with each other.
**''With a reference signal'' will compute the correlation of each signal of the active [[Geopsy: Signal Viewer|signal viewer]] with the selected signal in the combo box (one line of the correlation matrix). It is only possible to correlate the signals with one of them.

''Correlations'' modifies the [[Geopsy: Temporary Signal|temporary signal]].

'''Warning:''' The correlation of signals with a different starting and ending times cannot be computed. First [[Geopsy: Cut|cut]] the signals.
[[Image:CorrelationsEx.png|thumb|left|300px|Example of correlations between signals]]

==Use of correlation==
''Correlation'' between 2 signals (c.f. [[Wikipedia:Cross-correlation|Cross-Correlation]]) is able to give many different informations. First, the maximum in time gives the time delay between two signals. The spectra of the cross-correlations is the cross-power spectra. It enhances the frequencies common to the two signals.

==See also==
*[[Wikipedia:Cross-correlation|Cross-Correlation (Wikipedia)]]

@@ Line 10: / Line 10: @@
 **''With a reference signal'' will compute the correlation of each signal of the active [[Geopsy: Signal Viewer|signal viewer]] with the selected signal in the pop-up menu (one line of the correlation matrix). It is only possible to correlate the signals with one of them.
-''Correlations'' modifies the [[Geopsy: Temporary Signal|temporary signal]].
+''Correlations'' creates new [[Geopsy: Temporary Signal|temporary signals]] in the active [[Geopsy: Signal Viewer|signal viewer]].
 '''Warning:''' The correlation of signals with a different starting and ending times cannot be computed. In such a case, it is needed to first [[Geopsy: Cut|cut]] the signals.

@@ Line 16: / Line 16: @@
 ==Use of correlation==
-''Correlation'' between 2 signals (c.f. [[Wikipedia:Cross-correlation|Cross-Correlation]]) is able to give many different informations. First, the maximum in time gives the time delay between two signals. The spectra of the cross-correlations is the cross-power spectra. It enhances the frequencies common to the two signals.
+''Correlation'' between 2 signals (c.f. [[Wikipedia:Cross-correlation|Cross-Correlation]]) provides many different informations. The two basic one are the following :
 ==See also==
 *[[Wikipedia:Cross-correlation|Cross-Correlation (Wikipedia)]]

@@ Line 12: / Line 12: @@
 ''Correlations'' modifies the [[Geopsy: Temporary Signal|temporary signal]].
-'''Warning:''' The correlation of signals with a different starting and ending times cannot be computed. First [[Geopsy: Cut|cut]] the signals.
+'''Warning:''' The correlation of signals with a different starting and ending times cannot be computed. In such a case, it is needed to first [[Geopsy: Cut|cut]] the signals.
 [[Image:CorrelationsEx.png|thumb|left|300px|Example of correlations between signals]]

@@ Line 8: / Line 8: @@
 *Choice of the signal to correlate with the active signals. The possibilities are:
 **''Between all pairs of signals'' will compute all the parts of the correlation matrix, i.e. the correlation of each signal of the active [[Geopsy: Signal Viewer|signal viewer]] with each other.
-**''With a reference signal'' will compute the correlation of each signal of the active [[Geopsy: Signal Viewer|signal viewer]] with the selected signal in the combo box (one line of the correlation matrix). It is only possible to correlate the signals with one of them.
+**''With a reference signal'' will compute the correlation of each signal of the active [[Geopsy: Signal Viewer|signal viewer]] with the selected signal in the pop-up menu (one line of the correlation matrix). It is only possible to correlate the signals with one of them.
 ''Correlations'' modifies the [[Geopsy: Temporary Signal|temporary signal]].