FFT

Basic Information

Name of Program

FFT

Version-Date

2.x

Description-Date

August 2003

Catchwords

analysis of equidistant time series
spectral analysis
filter
fourier transformation
linear trend

Short Description of Functionality

The program FFT processes the time series results of different Mathematical Models for Coastal Areas and Estuaries as well as measured time series. FFT can filter the data, make a spectral analysis and compute a linear trend. It enables the user to modify the analysed data.

Input-Files

1. general input data (file of type fftein.dat)
2. measured or numerically computed time series (file of type boewrt.dat or knoerg.bin)

Bold text

Output-Files

1. lineprinter file with information about spectrum and time series (file of type fftsdr.dat)
2. filtered time series (file of type solwrt.dat)
3. batch file for the program ZEITRIO to convert the filtered time series into a file of type boewrt.dat
4. linear trend of a time series (file of type solwrt.dat)
5. original time series with the subtracted linear trend (file of type solwrt.dat)

Methodology

The program FFT may be used to analyse and modify time series with equidistant time steps. These are the features in detail:

• computation of a discrete spectrum by means of a fourier transformation
• computation of a power spectrum
• computation of correlating spectra and and of a function to correlate two time series
• diverse filter types
• computation of inverse fourier transformation; generation of an equidistant time series out of the (filtered) discrete spectrum
• computation of a linear trend
• subtraction of the linear trend from the original time series
• subtraction of the difference of the linear trends of two time series from the input data of the first originsl time series

Program(s) to run before this Program

MESKOR, XTRDATA, ZEITRIO

Program(s) to run after this Program

BOERND, EVENTFILTER, EXCELENZ, FRQWF, GVIEW2D, TIDKEN, TSCALC, UTRRND, ZEITRIO

Additional Information

Language

FORTRAN90

Additional software

-

Original Version

I. Uliczka

Maintenance

working group PRE

Documentation/Literature

please refer to $PROGHOME/examples/fft/

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