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Spectral analysis options

 
Movie BioloMICS: Spectral analysis, from 1.19 min.
 
Click on the button Options to see/change the parameters.
 
 
The upper section is used for the parameters of the smoothing step.
  • Average parameters (custom average smoothing):
The equation that is used is displayed on the top and the ‘a’, ‘b’, ‘c’, ‘d’ and ‘e’ are parameters that can be set as preferred to calculate the average.
a = Multiplication of the original value. Typical value: 4.0. Valid range: -10 to 10.
b = Multiplication of the values just before and after the original value. Typical value: 2.0. Valid range: -10 to 10.
c = Multiplication of the values 2 places before and after the original value. Typical value: 1.0. Valid range: -10 to 10.
d = Multiplication of the values 3 places before and after the original value. Typical value: 0.5. Valid range: -10 to 10
e = Multiplication of the values 4 places before and after the original value. Typical value: 0.25. Valid range: -10 to 10
 
  • Gaussian parameter (gauss smoothing):
The smaller the value the stronger the smoothing. If g =0.0, this is an average smoothing on 5 values. If g >= 5.0, the smoothing is nearly undetectable. Valid range: 0.0 to 5.0.
 
  • Flat average parameter (wide average smoothing):
‘r’ is number of points taken into account on either side. This means for the value 10 that there will be 10 point on the left and 10 on the right used.
 
The middle section is used for the parameters of the base line step.
  • Floating window width for SNIP. This is the width of the floating window used to compute the base line, in value index, not in X value. So if value is 20, the 10 points before and after the middle point are used during computation.
  • Floating window width for median. This is the width of the floating window used to compute the base line, in value index, not in X value. So if value is 20, the 10 points before and after the middle point are used during computation. Typical values are from 20 to 800. Start trial around 2% of the number of points in the spectra. Valid range is from 4 to 10.000.
  • Floating window width for top-hat. This is the width of the floating window used to compute the base line, in value index, not in X value. So if value is 20, the 10 points before and after the middle point are used during computation. Typical values are from 20 to 200. Valid range is from 4 to 10.000.
 
The bottom section is used for the parameters of the peak detection step.
  • Peak detection radius. This value represents the number of points used to find the valley points. If this value is 20, this means that a point is a valley point if the 20 points left and right are greater. Curve fittings used during peak detection are considering twice this number of points. Typical value is 40.
  • Peak minimum area ratio. If this value is 1000, peaks having a surface lower than the whole spectrum surface divided by 1000 (or 1%) are discarded. Typical value is 10.000.