# Fit Inspector

With this inspector some mathematical manipulation of data can be done.

## Smooth & Datareduction

**Data Reduction**: Sometimes it is useful to reduce a large number of data points which consist mainly of noise to a more practical amount of points. This function takes *n* points (*n* is specified in the *Factor* field), builds the average, and replaces the *n* points with the new one.

**FFT Smooth**: This functions uses as effective smooth width the value from the *Factor* field and performs a FFT based smooth to reduce the noise on the buffer (see sources).

**Smooth**: This functions uses as effective smooth width the value from the *Factor* field and performs a least square smooth to reduce the noise on the buffer.

## Spline Interpolation

This function calculates a nonparametric cubic spline interpolation (see sources) for all selected buffers.

**Points**: Defines the number of points which should be calculated for each interval.

**Strength**: Defines the *strength* of the interpolation. 2 is in most cases a god choice.

## Differentiate & Integrate

This function allow to differentiate and integrate buffers (see sources).

**Interval**: This the effective interval which will be used to calculate the differentiation.

**Differentiate**: Differentiate all selected buffer and generate new buffers with the result data.

**Integrate**: Integrates all selected buffer and generate new buffers with the result data. The integrate function does not need the interval.

## FFT (Fast Fourier Transform)

This function makes a Fast Fourier Transform for all selected buffers.

**Windowing**: This radio button defines the data windowing mode. For more information about FFT and data windowing read the sources.

## XPS

This two functions allow Shirley background subtraction and X-ray satellite subtraction from X-ray photoelectron spectra.

The reference points for Shirley backround subtraction can be defined with the *Shirley backround* mouse mode

**Find Y**: The Find Y button calculates optimal Y values which depend to the X values for the shirley background subtraction.

**Shirley**: Performs the Shirley background subtraction

**Satsub**: Performa the X-ray satellite subtraction for the given anode type.