text: //
  //  FFTHelper.h
  //  OpenSpirometry
  //
  //  Updated for objective-c implementation
  //
  //*  Real FFT wrapper for Apple's Accelerate Framework
  //*
  //*  Created by Parag K. Mital - http://pkmital.com
  //*  Contact: parag@pkmital.com
  //*
  //*  Copyright 2011 Parag K. Mital. All rights reserved.
  //  Modified by Eric Larson 2013.
  //  Copyright (c) 2013 Eric Larson. All rights reserved.
  //
  
  
  #import <Foundation/Foundation.h>
  #import <Accelerate/Accelerate.h>
  
  enum WindowType {
      WindowTypeHann,
      WindowTypeHamming,
      WindowTypeRect,
      WindowTypeBlackman,
  };
  
  @interface FFTHelper : NSObject
  
  @property (nonatomic,readonly) float *timeSeries; // for getting the invers FFT time series
  @property (nonatomic,readonly) size_t fftSize;
  @property (nonatomic,readonly) size_t fftSizeOver2;
  @property (nonatomic,readonly) size_t windowSize;
  
  - (id)init;
  - (id)initWithFFTSize: (int)fftSize;
  - (id)initWithFFTSize: (int)fftSize
              andWindow:(enum WindowType) winType;
  
  -(void)performForwardFFTWithData:(float*)data;
  -(void)copydBMagnitudeToBuffer:(float*)buffer;
  -(void)performForwardFFTWithData:(float*)data andCopydBMagnitudeToBuffer:(float*)buffer;
  
  
  //TODO: check inverse FFT and add to public API
  
  @end
  