af_approx

C interface for Interpolation. More...

Vector Interpolation
Vector (1D) interpolation. Parameters [out] d_YI Interpolated function values [in] n Number of elements in inputs d_Y [in] d_Y Function values [in] batch_Y Number of tiles of d_Y [in] ni Number of elements in d_XI [in] d_XI Grid values to interpolate at [in] batch_XI Number of tiles of d_XI [in] method interpolation type ('N' nearest, 'L' linear, 'C' cubic) [in] offgrid Value for interpolations off the grid (i.e. out-of-bounds)
afError	af_approx1_S (float *d_YI, unsigned n, const float *d_Y, unsigned batch_Y, unsigned ni, const float *d_XI, unsigned batch_XI, char method, float offgrid)
afError	af_approx1_D (double *d_YI, unsigned n, const double *d_Y, unsigned batch_Y, unsigned ni, const double *d_XI, unsigned batch_XI, char method, float offgrid)
afError	af_approx1_C (cfloat *d_YI, unsigned n, const cfloat *d_Y, unsigned batch_Y, unsigned ni, const float *d_XI, unsigned batch_XI, char method, float offgrid)
afError	af_approx1_Z (cdouble *d_YI, unsigned n, const cdouble *d_Y, unsigned batch_Y, unsigned ni, const double *d_XI, unsigned batch_XI, char method, float offgrid)

Matrix Interpolation
Matrix (2D) interpolation. Parameters [out] d_ZI Interpolated function values [in] nx Number of rows in d_Z [in] ny Number of columns in d_Z [in] d_Z Function values [in] batch_Z Number of tiles of d_Z [in] ni Number of elements in d_XI, d_YI [in] d_XI X Grid or Vector values to interpolate at [in] batch_XI Number of tiles of d_XI [in] d_YI Y Grid or Vector values to interpolate at [in] batch_YI Number of tiles of d_YI [in] method interpolation type ('N' nearest, 'L' linear, 'C' cubic) [in] offgrid Value for interpolations off the grid (i.e. out-of-bounds)
afError	af_approx2_S (float *d_ZI, unsigned nx, unsigned ny, const float *d_Z, unsigned batch_Z, unsigned ni, const float *d_XI, unsigned batch_XI, const float *d_YI, unsigned batch_YI, char method, float offgrid)
afError	af_approx2_D (double *d_ZI, unsigned nx, unsigned ny, const double *d_Z, unsigned batch_Z, unsigned ni, const double *d_XI, unsigned batch_XI, const double *d_YI, unsigned batch_YI, char method, float offgrid)
afError	af_approx2_C (cfloat *d_ZI, unsigned nx, unsigned ny, const cfloat *d_Z, unsigned batch_Z, unsigned ni, const float *d_XI, unsigned batch_XI, const float *d_YI, unsigned batch_YI, char method, float offgrid)
afError	af_approx2_Z (cdouble *d_ZI, unsigned nx, unsigned ny, const cdouble *d_Z, unsigned batch_Z, unsigned ni, const double *d_XI, unsigned batch_XI, const double *d_YI, unsigned batch_YI, char method, float offgrid)

Detailed Description

C interface for Interpolation.

approx1 and approx2 perform interpolation on data in one and two dimensions, respectively. These methods have three options for the type of interpolation to perform—nearest neighbor, linear interpolation, and cubic interpolation.

1D Example:

// Pass the values to arrayfire
float h_Y[] = {0,1,2,3,4,5,6};
array Y = array(7,h_Y);

// Interpolate for the following
float h_Xi[] = {1.2, 1.4, 1.6, 4, 700};
array Xi = array(5,h_Xi);

// Perform interpolation
array Yi = approx1(Y,    // Original sample data
                   Xi,   // locations for interpolation
                   'L'); // linear interpolation
print(Yi);
// Yi =
//        1.2000
//        1.4000
//        1.6000
//        4.0000
//           nan

2D Example:

float h_data[] = { 0.00, // (0,0)
                   0.10, // (1,0)
                   0.20, // (2,0)
                   0.01, // (0,1)
                   0.11, // (1,1)
                   0.21  // (2,1)
};

// Interpolate for the following
float h_Xirange[] = {1.2, 1.4, 1.6};
float h_Yirange[] = {0.3, 0.4, 0.6, 0.7};

// Pass the values to arrayfire
array data = array(3,2, h_data);

// Create a 2D grid from the 1D range vectors
array Xi = tile(array(3, 1, h_Xirange), 1, 4);
array Yi = tile(array(1, 4, h_Yirange), 3, 1);

// Perform interpolation
array result = approx2(data,    // Original sample data
                       Xi, Yi,  // locations for interpolation
                       'L');    // linear interpolation
print(result);
// result =
//     0.1230        0.1240        0.1260        0.1270
//     0.1430        0.1440        0.1460        0.1470
//     0.1630        0.1640        0.1660        0.1670

Function Documentation

afError af_approx1_S	(	float *	d_YI,
		unsigned	n,
		const float *	d_Y,
		unsigned	batch_Y,
		unsigned	ni,
		const float *	d_XI,
		unsigned	batch_XI,
		char	method,
		float	offgrid
	)

afError af_approx1_D	(	double *	d_YI,
		unsigned	n,
		const double *	d_Y,
		unsigned	batch_Y,
		unsigned	ni,
		const double *	d_XI,
		unsigned	batch_XI,
		char	method,
		float	offgrid
	)

afError af_approx1_C	(	cfloat *	d_YI,
		unsigned	n,
		const cfloat *	d_Y,
		unsigned	batch_Y,
		unsigned	ni,
		const float *	d_XI,
		unsigned	batch_XI,
		char	method,
		float	offgrid
	)

afError af_approx1_Z	(	cdouble *	d_YI,
		unsigned	n,
		const cdouble *	d_Y,
		unsigned	batch_Y,
		unsigned	ni,
		const double *	d_XI,
		unsigned	batch_XI,
		char	method,
		float	offgrid
	)

afError af_approx2_S	(	float *	d_ZI,
		unsigned	nx,
		unsigned	ny,
		const float *	d_Z,
		unsigned	batch_Z,
		unsigned	ni,
		const float *	d_XI,
		unsigned	batch_XI,
		const float *	d_YI,
		unsigned	batch_YI,
		char	method,
		float	offgrid
	)

afError af_approx2_D	(	double *	d_ZI,
		unsigned	nx,
		unsigned	ny,
		const double *	d_Z,
		unsigned	batch_Z,
		unsigned	ni,
		const double *	d_XI,
		unsigned	batch_XI,
		const double *	d_YI,
		unsigned	batch_YI,
		char	method,
		float	offgrid
	)

afError af_approx2_C	(	cfloat *	d_ZI,
		unsigned	nx,
		unsigned	ny,
		const cfloat *	d_Z,
		unsigned	batch_Z,
		unsigned	ni,
		const float *	d_XI,
		unsigned	batch_XI,
		const float *	d_YI,
		unsigned	batch_YI,
		char	method,
		float	offgrid
	)

afError af_approx2_Z	(	cdouble *	d_ZI,
		unsigned	nx,
		unsigned	ny,
		const cdouble *	d_Z,
		unsigned	batch_Z,
		unsigned	ni,
		const double *	d_XI,
		unsigned	batch_XI,
		const double *	d_YI,
		unsigned	batch_YI,
		char	method,
		float	offgrid
	)