Miscellaneous <br>

Classes
class	gr::fxpt
	fixed point sine and cosine and friends. More...
class	gr::fxpt_nco
	Numerically Controlled Oscillator (NCO) More...
class	gr::fxpt_vco
	Voltage Controlled Oscillator (VCO) More...
class	gr::message
	Message class. More...
class	gr::msg_queue
	thread-safe message queue More...
class	gr::nco< o_type, i_type >
	base class template for Numerically Controlled Oscillator (NCO) More...
class	gr::prefs
	Base class for representing user preferences a la windows INI files. More...
class	gr::blocks::lfsr_15_1_0
	Linear Feedback Shift Register using primitive polynomial x^15 + x + 1. More...
class	gr::blocks::lfsr_32k
	generate pseudo-random sequence of length 32768 bits. More...
class	gr::digital::lfsr
	Fibonacci Linear Feedback Shift Register using specified polynomial mask. More...
struct	gr::fft::fft_inbuf< T, forward >
	FFT: templated. More...
class	gr::fft::goertzel
	Implements Goertzel single-bin DFT calculation. More...
class	gr::wavelet::squash_ff
	Implements cheap resampling of spectrum directly from spectral points, using gsl interpolation. More...

Functions
GR_RUNTIME_API float	gr::fast_atan2f (float y, float x)
	Fast arc tangent using table lookup and linear interpolation. More...
GR_RUNTIME_API rt_status_t	gr::enable_realtime_scheduling ()
	If possible, enable high-priority "real time" scheduling. More...

Detailed Description

Function Documentation

enable_realtime_scheduling()

GR_RUNTIME_API rt_status_t gr::enable_realtime_scheduling

(

)

If possible, enable high-priority "real time" scheduling.

fast_atan2f()

GR_RUNTIME_API float gr::fast_atan2f	(	float	y,
		float	x
	)

Fast arc tangent using table lookup and linear interpolation.

Parameters

y	component of input vector
x	component of input vector

Returns

float angle angle of vector (x, y) in radians

This function calculates the angle of the vector (x,y) based on a table lookup and linear interpolation. The table uses a 256 point table covering -45 to +45 degrees and uses symmetry to determine the final angle value in the range of -180 to 180 degrees. Note that this function uses the small angle approximation for values close to zero. This routine calculates the arc tangent with an average error of +/- 0.045 degrees.

Referenced by gr::fast_atan2f().