Dec 232017

Fast Fourier Transforms in Turbo Pascal. | |||
---|---|---|---|

File Name | File Size | Zip Size | Zip Type |

FFT12.COM | 35456 | 20127 | deflated |

FFT12.DOC | 4352 | 1710 | deflated |

FFT12.PAS | 7808 | 2302 | deflated |

GETDATA2.COM | 11008 | 7903 | deflated |

GETDATA2.PAS | 1792 | 685 | deflated |

PROCWRIT.PAS | 768 | 316 | deflated |

# Download File FFT12.ZIP Here

## Contents of the FFT12.DOC file

Fast Fourier Transform

ver 1.2

by

Michael F.Griffin

Childrens Hospital Research Foundation

Division of Cardiology

Biomedical Engineering Laboratory

Elland & Bethesda Aves

Cincinnati,Ohio 45229

The Fast Fourier Transform (FFT) is a computationally efficient

algorithm to compute the discrete fourier transform.

There are two methods that are commonly used to compute the

FFT: Decimation in Time and Decimation in Frequency. The author

chooses to use the decimation in time.

The FFT programs written by the author assume that the user

has some background knowledge.

The FFT programs require that the number of data points be a

power of two. Some modifications would be needed to transform a

length other than a power of two. Please contact the author if

you are interested in the modifications.

If you are using real data the computational efficiency can

be further improved by modifying the transform to take advantage

of certain properties of Fourier Transforms.

Modifications:

--------------

- added Turbo Graphix Toolbox routines for plots

- magnitude and phase (-pi/2 to pi/2) are displayed versus N points

- GETDATA.PAS slightly modified ===> GETDATA2.PAS

- FFT.COM requires both 8087 & Hercules Graphics board

Problems:

---------

- If the real parts are zero, you will get a run-time error

regarding a divide by zero during phase calculations. This

will try to be corrected on future versions.

List of some Fourier Analysis Programs available

------------------------------------------------

FFT.PAS - Turbo Pascal version of a complete FFT program

with data input from files and data output to

either files or printer.

The program works but could use a little work

on the input and output sections.

It does not know if an output file already

exists and could write over another data file.

FFT.COM - Compiled version of the above.

PROCFFT.PAS - Turbo Pascal FFT 'procedure'.

CHIRPZ.COM - Evaluating the Fourier Transform along a different contour.

FFT.EXE - Compiled Basica FFT.

FFT.BAS - Source code for FFT.EXE.

DFT.EXE - Discrete Fourier Transform - Compiled Basica

DFT.BAS - Source code for DFT.EXE

Data gathering for the Turbo Pascal FFT's

GETDATA2.PAS - Crude program to enter complex data into a

random access file. This program was written

to enter test data. Although it is crude, it

works. In most cases the data will be gathered

from a source and dumped into a random access

file that can be read by the program. If

entering data by hand is desired, this file

needs to be modified so that an editing

capability is added.

GETDATA2.COM- Turbo-87 compiled version of GETDATA2.PAS.

- requires an 8087

Hopefully, the author will find time to modify some of the

problems mentioned above. If not, you are more than welcome to

modify them yourselves. If you do modify the programs, please

download them to the Biomedical Engineering RBBS.

List of some future programs

----------------------------

Two Dimensional FFT - FFT for image data.

Complex Cepstrum - Log Spectrum.

Please send any corrections, modifications, suggestions, or

ideas to the address listed or leave a message on the RBBS. If

you are having any problems, feel free to call between 9am and

6pm on weekdays.

Biomedical Engineering RBBS

---------------------------

data/voice: 513-559-8599

RBBS hours: 1800-0900 weekdays

: 24 hours weekends

: Eastern Standard Time

4/29/85

ver 1.2

by

Michael F.Griffin

Childrens Hospital Research Foundation

Division of Cardiology

Biomedical Engineering Laboratory

Elland & Bethesda Aves

Cincinnati,Ohio 45229

The Fast Fourier Transform (FFT) is a computationally efficient

algorithm to compute the discrete fourier transform.

There are two methods that are commonly used to compute the

FFT: Decimation in Time and Decimation in Frequency. The author

chooses to use the decimation in time.

The FFT programs written by the author assume that the user

has some background knowledge.

The FFT programs require that the number of data points be a

power of two. Some modifications would be needed to transform a

length other than a power of two. Please contact the author if

you are interested in the modifications.

If you are using real data the computational efficiency can

be further improved by modifying the transform to take advantage

of certain properties of Fourier Transforms.

Modifications:

--------------

- added Turbo Graphix Toolbox routines for plots

- magnitude and phase (-pi/2 to pi/2) are displayed versus N points

- GETDATA.PAS slightly modified ===> GETDATA2.PAS

- FFT.COM requires both 8087 & Hercules Graphics board

Problems:

---------

- If the real parts are zero, you will get a run-time error

regarding a divide by zero during phase calculations. This

will try to be corrected on future versions.

List of some Fourier Analysis Programs available

------------------------------------------------

FFT.PAS - Turbo Pascal version of a complete FFT program

with data input from files and data output to

either files or printer.

The program works but could use a little work

on the input and output sections.

It does not know if an output file already

exists and could write over another data file.

FFT.COM - Compiled version of the above.

PROCFFT.PAS - Turbo Pascal FFT 'procedure'.

CHIRPZ.COM - Evaluating the Fourier Transform along a different contour.

FFT.EXE - Compiled Basica FFT.

FFT.BAS - Source code for FFT.EXE.

DFT.EXE - Discrete Fourier Transform - Compiled Basica

DFT.BAS - Source code for DFT.EXE

Data gathering for the Turbo Pascal FFT's

GETDATA2.PAS - Crude program to enter complex data into a

random access file. This program was written

to enter test data. Although it is crude, it

works. In most cases the data will be gathered

from a source and dumped into a random access

file that can be read by the program. If

entering data by hand is desired, this file

needs to be modified so that an editing

capability is added.

GETDATA2.COM- Turbo-87 compiled version of GETDATA2.PAS.

- requires an 8087

Hopefully, the author will find time to modify some of the

problems mentioned above. If not, you are more than welcome to

modify them yourselves. If you do modify the programs, please

download them to the Biomedical Engineering RBBS.

List of some future programs

----------------------------

Two Dimensional FFT - FFT for image data.

Complex Cepstrum - Log Spectrum.

Please send any corrections, modifications, suggestions, or

ideas to the address listed or leave a message on the RBBS. If

you are having any problems, feel free to call between 9am and

6pm on weekdays.

Biomedical Engineering RBBS

---------------------------

data/voice: 513-559-8599

RBBS hours: 1800-0900 weekdays

: 24 hours weekends

: Eastern Standard Time

4/29/85

December 23, 2017
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