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SIGNAL/RTS APPLICATION NOTES

4 Application Note 11

fid = fopen ('rfile','rb');

fseek(fid,1024,'bof');

A = fread (fid,inf,'float32');

3. Example: calculate the power spectrum of TWEET.1 in SIGNAL and store it as a

SIGNAL-header floating point file, then read and plot this file in MATLAB. To display this

file correctly, you must know its FFT length (8192 points) and sample rate (25000 Hz).

>R T 1 In SIGNAL

Filename: C:\SIGNAL\TWEET.1

>XF T 1 1

>W F 1

Filename: TWEET.F

fid = fopen ('tweet.f','rb'); In MATLAB

fseek(fid,1024,'bof');

A = fread (fid,inf,'float32');

X = [0:(length(A)-1)] * (25000/8192);

plot(X,A);

Headerless floating point files

1. Write the SIGNAL T or F buffer to a headerless floating point file. The following will

write time buffer 1 to the headerless file RFILE in floating point (/F) format.

>W T 1 /B /F

Filename: RFILE

2. Read the file into a MATLAB array. The following MATLAB commands will read the

entire floating point file RFILE into the array A.

fid = fopen ('rfile','rb');

A = fread (fid,inf,'float32');

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Engineering Design NIDisk Guia do Utilizador Página 28