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arduinoFFT
kopia lustrzana https://github.com/kosme/arduinoFFT
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Add nuttall & blackman complimentary windowing 

Add functions for nuttall, blackman-nuttall and blackman-harris windowing
pull/22/head
Dantali0n 2018-10-26 12:24:13 +02:00
rodzic a060c2f7d1
commit 68e59c2e61
4 zmienionych plików z 33 dodań i 5 usunięć
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3
README.md
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@ -68,7 +68,10 @@ Performs a windowing function on the values array. The possible windowing option
* FFT_WIN_TYP_HAMMING
* FFT_WIN_TYP_HANN
* FFT_WIN_TYP_TRIANGLE
* FFT_WIN_TYP_NUTTALL
* FFT_WIN_TYP_BLACKMAN
* FFT_WIN_TYP_BLACKMAN_NUTTALL
* FFT_WIN_TYP_BLACKMAN_HARRIS
* FFT_WIN_TYP_FLT_TOP
* FFT_WIN_TYP_WELCH
* **Exponent**(uint16_t value);

3
keywords.txt
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@ -31,6 +31,9 @@ FFT_WIN_TYP_RECTANGLE LITERAL1
FFT_WIN_TYP_HAMMING LITERAL1
FFT_WIN_TYP_HANN LITERAL1
FFT_WIN_TYP_TRIANGLE LITERAL1
FFT_WIN_TYP_NUTTALL LITERAL1
FFT_WIN_TYP_BLACKMAN LITERAL1
FFT_WIN_TYP_BLACKMAN_NUTTALL LITERAL1
FFT_WIN_TYP_BLACKMAN_HARRIS LITERAL1
FFT_WIN_TYP_FLT_TOP LITERAL1
FFT_WIN_TYP_WELCH LITERAL1

22
src/arduinoFFT.cpp
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@ -199,9 +199,18 @@ void arduinoFFT::Windowing(uint8_t windowType, uint8_t dir)
case FFT_WIN_TYP_TRIANGLE: // triangle (Bartlett)
weighingFactor = 1.0 - ((2.0 * abs(indexMinusOne - (samplesMinusOne / 2.0))) / samplesMinusOne);
break;
case FFT_WIN_TYP_BLACKMAN: // blackmann
case FFT_WIN_TYP_NUTTALL: // nuttall
weighingFactor = 0.355768 - (0.487396 * (cos(twoPi * ratio))) + (0.144232 * (cos(fourPi * ratio))) - (0.012604 * (cos(sixPi * ratio)));
break;
case FFT_WIN_TYP_BLACKMAN: // blackman
weighingFactor = 0.42323 - (0.49755 * (cos(twoPi * ratio))) + (0.07922 * (cos(fourPi * ratio)));
break;
case FFT_WIN_TYP_BLACKMAN_NUTTALL: // blackman nuttall
weighingFactor = 0.3635819 - (0.4891775 * (cos(twoPi * ratio))) + (0.1365995 * (cos(fourPi * ratio))) - (0.0106411 * (cos(sixPi * ratio)));
break;
case FFT_WIN_TYP_BLACKMAN_HARRIS: // blackman harris
weighingFactor = 0.35875 - (0.48829 * (cos(twoPi * ratio))) + (0.14128 * (cos(fourPi * ratio))) - (0.01168 * (cos(sixPi * ratio)));
break;
case FFT_WIN_TYP_FLT_TOP: // flat top
weighingFactor = 0.2810639 - (0.5208972 * cos(twoPi * ratio)) + (0.1980399 * cos(fourPi * ratio));
break;
@ -244,9 +253,18 @@ void arduinoFFT::Windowing(double *vData, uint16_t samples, uint8_t windowType,
case FFT_WIN_TYP_TRIANGLE: // triangle (Bartlett)
weighingFactor = 1.0 - ((2.0 * abs(indexMinusOne - (samplesMinusOne / 2.0))) / samplesMinusOne);
break;
case FFT_WIN_TYP_BLACKMAN: // blackmann
case FFT_WIN_TYP_NUTTALL: // nuttall
weighingFactor = 0.355768 - (0.487396 * (cos(twoPi * ratio))) + (0.144232 * (cos(fourPi * ratio))) - (0.012604 * (cos(sixPi * ratio)));
break;
case FFT_WIN_TYP_BLACKMAN: // blackman
weighingFactor = 0.42323 - (0.49755 * (cos(twoPi * ratio))) + (0.07922 * (cos(fourPi * ratio)));
break;
case FFT_WIN_TYP_BLACKMAN_NUTTALL: // blackman nuttall
weighingFactor = 0.3635819 - (0.4891775 * (cos(twoPi * ratio))) + (0.1365995 * (cos(fourPi * ratio))) - (0.0106411 * (cos(sixPi * ratio)));
break;
case FFT_WIN_TYP_BLACKMAN_HARRIS: // blackman harris
weighingFactor = 0.35875 - (0.48829 * (cos(twoPi * ratio))) + (0.14128 * (cos(fourPi * ratio))) - (0.01168 * (cos(sixPi * ratio)));
break;
case FFT_WIN_TYP_FLT_TOP: // flat top
weighingFactor = 0.2810639 - (0.5208972 * cos(twoPi * ratio)) + (0.1980399 * cos(fourPi * ratio));
break;

10
src/arduinoFFT.h
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@ -48,12 +48,16 @@
#define FFT_WIN_TYP_HAMMING 0x01 /* hamming */
#define FFT_WIN_TYP_HANN 0x02 /* hann */
#define FFT_WIN_TYP_TRIANGLE 0x03 /* triangle (Bartlett) */
#define FFT_WIN_TYP_BLACKMAN 0x04 /* blackmann */
#define FFT_WIN_TYP_FLT_TOP 0x05 /* flat top */
#define FFT_WIN_TYP_WELCH 0x06 /* welch */
#define FFT_WIN_TYP_NUTTALL 0x04 /* nuttall */
#define FFT_WIN_TYP_BLACKMAN 0x05 /* blackman */
#define FFT_WIN_TYP_BLACKMAN_NUTTALL 0x06 /* blackman nuttall */
#define FFT_WIN_TYP_BLACKMAN_HARRIS 0x07 /* blackman harris*/
#define FFT_WIN_TYP_FLT_TOP 0x08 /* flat top */
#define FFT_WIN_TYP_WELCH 0x09 /* welch */
/*Mathematial constants*/
#define twoPi 6.28318531
#define fourPi 12.56637061
#define sixPi 18.84955593
class arduinoFFT {
public: