The Calculate noise at frequency dialog


In order to check the significance of a detected frequency it is neccessary to calculate the signal to noise ratio. For this purpose select "Calculate noise at frequency" in the Special menu.

Calculate noise at Frequency Defines the frequency for which the noise should be calculated. The frequencies that are stored in the frequency list in the Fit module are accessible by the combo box below the frequency field. By default the last frequency of the frequency list is activated.
Box size: Determines the size of the frequency range to be used for the noise calculation:
[frequency-box/2, frequency+box/2]
Step rate: Defines the accuracy of the frequency grid for the Fourier calculation. Three default options for the step rate quality are available and can be selected by the combo box: High, Medium and Low. In order to set a user-defined value, select Custom and type the value into the input field next to the step rate combo-box. Please note: The smaller the step rate the longer the calculation will take.
Calculations based on Defines the type of data to be used for the calculation: Original data, Adjusted data, Residuals at original, Residuals at adjusted or Spectral window.

Click on Calculate to start the calculation. The results of the noise calculation will be shown in the text field below. If the frequency has been selected via the combo box then even a value for the signal to noise ratio will be calculated.

You can export or print the content of the text box by pressing the appropriate button.