gridpp Namespace Reference

Typedefs
Short-hand notation for vectors of different dimensions sizes
typedef std::vector< float >	vec
typedef std::vector< vec >	vec2
typedef std::vector< vec2 >	vec3
typedef std::vector< int >	ivec
typedef std::vector< ivec >	ivec2
typedef std::vector< ivec2 >	ivec3
typedef std::vector< double >	dvec
typedef std::vector< dvec >	dvec2

Functions
Data assimilation methods
Functions that merge observations with a background field
vec2	optimal_interpolation (const Grid &bgrid, const vec2 &background, const Points &points, const vec &pobs, const vec &pratios, const vec &pbackground, const StructureFunction &structure, int max_points)
	Optimal interpolation for a deterministic gridded field. More...
vec	optimal_interpolation (const Points &bpoints, const vec &background, const Points &points, const vec &pobs, const vec &pratios, const vec &pbackground, const StructureFunction &structure, int max_points)
	Optimal interpolation for a deterministic vector of points. More...
vec2	optimal_interpolation_transform (const Grid &bgrid, const vec2 &background, float bsigma, const Points &points, const vec &pobs, const vec &psigmas, const vec &pbackground, const StructureFunction &structure, int max_points, const Transform &transform)
	This is its own function because the variance parameterization is different than in the non-transformed case. More...
vec	optimal_interpolation_transform (const Points &bpoints, const vec &background, float bsigma, const Points &points, const vec &pobs, const vec &psigmas, const vec &pbackground, const StructureFunction &structure, int max_points, const Transform &transform)
vec3	optimal_interpolation_ensi (const Grid &bgrid, const vec3 &background, const Points &points, const vec &pobs, const vec &psigmas, const vec2 &pbackground, const StructureFunction &structure, int max_points)
	Optimal interpolation using a structure function based on an ensemble See Lussana et al 2019 (DOI: 10.1002/qj.3646) More...
vec2	optimal_interpolation_ensi (const Points &bpoints, const vec2 &background, const Points &points, const vec &pobs, const vec &psigmas, const vec2 &pbackground, const StructureFunction &structure, int max_points)
vec2	fill (const Grid &igrid, const vec2 &input, const Points &points, const vec &radii, float value, bool outside)
	Fill in values inside or outside a set of circles. More...
Spatial neighbourhood filters
Functions that apply neighbourhood filters on a gridded field
vec2	neighbourhood (const vec2 &input, int halfwidth, Statistic statistic)
	Spatial neighbourhood filter, computing a statistic for a sliding square window. More...
vec2	neighbourhood (const vec3 &input, int halfwidth, Statistic statistic)
	Spatial neighbourhood filter for an ensemble of fields. More...
vec2	neighbourhood_quantile (const vec2 &input, float quantile, int halfwidth)
	Computes a quantile in a sliding square neighbourhood. More...
vec2	neighbourhood_quantile (const vec3 &input, float quantile, int halfwidth)
	Computes a quantile in a sliding square neighbourhood for an ensemble of fields. More...
vec2	neighbourhood_quantile_fast (const vec2 &input, float quantile, int halfwidth, const vec &thresholds)
	Fast and approximate neighbourhood quantile. More...
vec2	neighbourhood_quantile_fast (const vec3 &input, float quantile, int halfwidth, const vec &thresholds)
	Fast and approximate neighbourhood quantile for ensemble of fields. More...
vec2	neighbourhood_quantile_fast (const vec2 &input, const vec2 &quantile, int halfwidth, const vec &thresholds)
	Fast and approximate neighbourhood quantile, with spatially varying quantile. More...
vec2	neighbourhood_quantile_fast (const vec3 &input, const vec2 &quantile, int halfwidth, const vec &thresholds)
	Fast and approximate neighbourhood quantile for ensemble of fields, with spatially varying quantile. More...
vec2	neighbourhood_brute_force (const vec2 &input, int halfwidth, Statistic statistic)
	Spatial neighbourhood filter without any shortcuts. More...
vec2	neighbourhood_brute_force (const vec3 &input, int halfwidth, Statistic statistic)
	Spatial neighbourhood filter without any shortcuts. More...
vec	get_neighbourhood_thresholds (const vec2 &input, int num_thresholds)
	Calculate appropriate approximation thresholds for neighbourhood quantile. More...
vec	get_neighbourhood_thresholds (const vec3 &input, int num_thresholds)
	Calculate appropriate approximation thresholds for neighbourhood quantile based on an * ensemble. More...
vec2	neighbourhood_ens (const vec3 &input, int halfwidth, Statistic statistic)
	Deprecated: Compute neighbourhood statistic on ensemble field. More...
vec2	neighbourhood_quantile_ens (const vec3 &input, float quantile, int halfwidth)
	Deprecated: Compute neighbourhood quantiles on ensemble field. More...
vec2	neighbourhood_quantile_ens_fast (const vec3 &input, float quantile, int radius, const vec &thresholds)
	Deprecated: Compute neighbourhood quantiles fast on ensemble field. More...
Calibration methods
Functions that apply statistical methods to data
vec2	quantile_mapping_curve (const vec &ref, const vec &fcst, vec quantiles=vec())
	Create quantile mapping calibration curve. More...
vec2	metric_optimizer_curve (const vec &ref, const vec &fcst, const vec &thresholds, Metric metric)
	Create calibration curve that optimizes a metric. More...
vec	apply_curve (const vec &fcst, const vec2 &curve, Extrapolation policy_below, Extrapolation policy_above)
	Apply arbitrary calibration curve to 1D forecasts. More...
vec2	apply_curve (const vec2 &fcst, const vec2 &curve, Extrapolation policy_below, Extrapolation policy_above)
	Apply arbitrary calibration curve to 2D forecasts. More...
vec2	monotonize_curve (vec2 curve)
	Ensure calibration curve is monotonic, by removing points. More...
float	get_optimal_threshold (const vec &ref, const vec &fcst, float threshold, Metric metric)
float	calc_score (float a, float b, float c, float d, Metric metric)
float	calc_score (const vec &ref, const vec &fcst, float threshold, Metric metric)
float	calc_score (const vec &ref, const vec &fcst, float threshold, float fthreshold, Metric metric)
vec2	correction (const Grid &rgrid, const vec2 &rvalues, const Points &npoints, const vec &nvalues, float mean_radius, float outer_radius, float inner_radius, int min_num, int max_num, CorrectionType type, ivec2 &count)
vec2	correction (const Grid &rgrid, const vec3 &rvalues, const Points &npoints, const vec2 &nvalues, const vec2 &apply_values, float mean_radius, float outer_radius, float inner_radius, int min_num, int max_num, CorrectionType type, ivec2 &count)
Downscaling methods
Functions that interpolate data from one grid to another
vec2	nearest (const Grid &igrid, const Grid &ogrid, const vec2 ivalues)
	Nearest neighbour dowscaling grid to grid. More...
vec3	nearest (const Grid &igrid, const Grid &ogrid, const vec3 ivalues)
vec	nearest (const Grid &igrid, const Points &opoints, const vec2 ivalues)
	Nearest neighbour dowscaling grid to point. More...
vec2	nearest (const Grid &igrid, const Points &opoints, const vec3 ivalues)
vec2	bilinear (const Grid &igrid, const Grid &ogrid, const vec2 ivalues)
	Bilinear downscaling grid to grid. More...
vec	bilinear (const Grid &igrid, const Points &opoints, const vec2 ivalues)
	Bilinear downscaling grid to points. More...
vec2	simple_gradient (const Grid &igrid, const Grid &ogrid, const vec2 ivalues, float elev_gradient)
vec	simple_gradient (const Grid &igrid, const Points &opoints, const vec2 ivalues, float elev_gradient)
vec2	smart (const Grid &igrid, const Grid &ogrid, const vec2 &ivalues, int num, const StructureFunction &structure)
	Smart neighbour downscaling grid to grid. More...
Grid calculations
Functions that calculate statistics on a grid
vec	count (const Grid &grid, const Points &points, float radius)
	For each point, counts the number of gridpoints within the radius. More...
vec2	count (const Points &points, const Grid &grid, float radius)
	For each gridpoint, counts the number of points within the radius. More...
vec	distance (const Grid &grid, const Points &points, int num=1)
	For each point, calculates the distance to nearest gridpoint. More...
vec2	distance (const Grid &igrid, const Grid &ogrid, int num=1)
	For each output gridpoint, calculate the distance to nearest input gridpoint. More...
vec2	distance (const Points &points, const Grid &grid, int num=1)
	For each gridpoint, calculates the distance to nearest point. More...
vec2	fill_missing (const vec2 &values)
	Fill in missing values based on nearby values. More...
vec2	gridding (const Grid &grid, const Points &points, const vec &values, float radius, int min_num, Statistic statistic)
	Aggregate points onto a grid. More...
Diagnosing meteorological variables
Functions that diagnose a meteorological variable based on other variables
float	dewpoint (float temperature, float relative_humidity)
	Calculate dewpoint temperature from temperature and relative humidity. More...
vec	dewpoint (const vec &temperature, const vec &relative_humidity)
	Vector version of dewpoint calculation. More...
float	pressure (float ielev, float oelev, float ipressure, float itemperature=288.15)
	Calculate pressure at a new elevation. More...
vec	pressure (const vec &ielev, const vec &oelev, const vec &ipressure, const vec &itemperature)
	Calculate Vector version of pressure calculation. More...
float	qnh (float pressure, float altitude)
	Diagnose QNH from pressure and altitude. More...
vec	qnh (const vec &pressure, const vec &altitude)
	Vector version of QNH calculation. More...
float	relative_humidity (float temperature, float dewpoint)
	Calculate relative humidity from temperature and dewpoint temperature. More...
vec	relative_humidity (const vec &temperature, const vec &dewpoint)
	Vector version of relative humidity calculation. More...
float	wetbulb (float temperature, float pressure, float relative_humidity)
	Calculate wetbulb temperature from temperature, pressure, and relative humidity. More...
vec	wetbulb (const vec &temperature, const vec &pressure, const vec &relative_humidity)
	Vector version of wetbulb calculation. More...
float	wind_speed (float xwind, float ywind)
	Diagnose wind speed from its components. More...
vec	wind_speed (const vec &xwind, const vec &ywind)
	Vector version of wind speed calculation. More...
float	wind_direction (float xwind, float ywind)
	Diagnose wind direction from its components. More...
vec	wind_direction (const vec &xwind, const vec &ywind)
	Vector version of wind direction calculation. More...
OpenMP settings
Functions that configure OpenMP
void	set_omp_threads (int num)
	Set the number of OpenMP threads to use. More...
void	initialize_omp ()
	Sets the number of OpenMP threads to 1 if OMP_NUM_THREADS undefined. More...
Utilities
Helper functions
Statistic	get_statistic (std::string name)
	Convert name of a statistic enum. More...
std::string	version ()
	The gridpp version. More...
double	clock ()
void	debug (std::string string)
void	warning (std::string string)
void	error (std::string string)
void	future_deprecation_warning (std::string function, std::string other="")
bool	is_valid (float value)
float	calc_statistic (const vec &array, Statistic statistic)
float	calc_quantile (const vec &array, float quantile)
vec	calc_statistic (const vec2 &array, Statistic statistic)
vec	calc_quantile (const vec2 &array, float quantile=MV)
int	num_missing_values (const vec2 &iArray)
int	get_lower_index (float iX, const std::vector< float > &iValues)
	Find the index in a vector that is equal or just below a value. More...
int	get_upper_index (float iX, const std::vector< float > &iValues)
	Find the index in a vector that is equal or just above a value. More...
float	interpolate (float x, const std::vector< float > &iX, const std::vector< float > &iY)
	Piecewise linear interpolation If x is outside the range of iX, then the min/max value of iY is used. More...
ivec2	init_ivec2 (int Y, int X, int value)
	Initialize a vector of size Y, X, with a given value. More...
vec2	init_vec2 (int Y, int X, float value=MV)
ivec3	init_ivec3 (int Y, int X, int E, int value)
	Initialize a vector of size Y, X, E, with a given value. More...
vec3	init_vec3 (int Y, int X, int E, float value=MV)
vec	calc_even_quantiles (const vec &values, int num)
	Get reasonably spaced quantiles from a vector of values, ignoring duplicate values but including the first number after duplicated values. More...
vec2	calc_gradient (const Grid &grid, const vec2 &base, const vec2 &values, int radius, int min_num=2, float min_range=0, float default_gradient=0)
	Computes gradients based on values in neighbourhood. More...
bool	compatible_size (const Grid &grid, const vec2 &v)
	Check if the grid is the same size as the 2D vector. More...
bool	compatible_size (const Grid &grid, const vec3 &v)
bool	point_in_rectangle (const Point &A, const Point &B, const Point &C, const Point &D, const Point &m)
	Checks if a point is located inside a rectangle formed by 4 points. More...

Variables
Constants
Functions that assimilate observations onto a gridded background
static const float	MV = NAN
	Missing value indicator. More...
static const float	MV_CML = -999
	Missing value indicator in gridpp command-line tool. More...
static const float	pi = 3.14159265
	Mathematical constant pi. More...
static const double	radius_earth = 6.378137e6
	Radius of the earth [m]. More...

Enumerations
enum	CoordinateType { Geodetic = 0, Cartesian = 1 }
	Types of coordinates for position of points. More...
enum	CorrectionType { Qq = 0, Multiplicative = 10, Additive = 20 }
	Method for statistical correction. More...
enum	Extrapolation { OneToOne = 0, MeanSlope = 10, NearestSlope = 20, Zero = 30 }
	Methods for extrapolating outside a curve. More...
enum	Metric {   Ets = 0, Ts = 1, Kss = 20, Pc = 30,   Bias = 40, Hss = 50 }
	Binary verification metrics. More...
enum	Statistic {   Mean = 0, Min = 10, Median = 20, Max = 30,   Quantile = 40, Std = 50, Variance = 60, Sum = 70,   Unknown = -1 }
	Statistical operations to reduce a vector to a scalar. More...

Classes
class	BarnesStructure
	Simple structure function based on distance, elevation, and land area fraction. More...
class	BoxCox
class	CressmanStructure
	Simple structure function based on distance, elevation, and land area fraction. More...
class	CrossValidation
class	Grid
	Represents a 2D grid of locations and their metadata. More...
class	Identity
class	KDTree
	Helper class for Grid and Points. More...
class	Log
class	not_implemented_exception
class	Point
	Represents a single point in some coordinate system. More...
class	Points
	Represents a vector of locations and their metadata. More...
class	StructureFunction
	Covariance structure function. More...
class	Transform

SWIG testing functions
Functions for testing the SWIG interface. Not useful for any other purpose.
static const float	swig_default_value = -1
	Default value used to fill array in SWIG testing functions. More...
float *	test_array (float *v, int n)
	Special function whose presense is needed for SWIG. More...
float	test_vec_input (const vec &input)
	Testing function for 1D input vector. More...
int	test_ivec_input (const ivec &input)
	Testing function for 1D input vector. More...
float	test_vec2_input (const vec2 &input)
	Testing function for 2D input vector. More...
float	test_vec3_input (const vec3 &input)
	Testing function for 3D input vector. More...
vec	test_vec_output ()
	Testing function for 1D output vector. More...
ivec	test_ivec_output ()
vec2	test_vec2_output ()
	Testing function for 2D output vector. More...
ivec2	test_ivec2_output ()
vec3	test_vec3_output ()
	Testing function for 3D output vector. More...
ivec3	test_ivec3_output ()
float	test_vec_argout (vec &distances)
	Testing function for 1D vector treated as output. More...
float	test_vec2_argout (vec2 &distances)
	Testing function for 2D vector treated as output. More...
void	test_not_implemented_exception ()

Typedef Documentation

dvec

typedef std::vector<double> gridpp::dvec

dvec2

typedef std::vector<dvec> gridpp::dvec2

ivec

typedef std::vector<int> gridpp::ivec

ivec2

typedef std::vector<ivec> gridpp::ivec2

ivec3

typedef std::vector<ivec2> gridpp::ivec3

vec

typedef std::vector<float> gridpp::vec

vec2

typedef std::vector<vec> gridpp::vec2

vec3

typedef std::vector<vec2> gridpp::vec3

Enumeration Type Documentation

CoordinateType

enum gridpp::CoordinateType

Types of coordinates for position of points.

Enumerator
Geodetic	Latitude and longitude.
Cartesian	X and Y.

CorrectionType

enum gridpp::CorrectionType

Method for statistical correction.

Enumerator
Qq	Quantile mapping.
Multiplicative	Multiplicative.
Additive	Additive.

Extrapolation

enum gridpp::Extrapolation

Methods for extrapolating outside a curve.

Enumerator
OneToOne	Continue past the end-points using a slope of 1.
MeanSlope	Continue past the end-points using the mean slope of the curve.
NearestSlope	Continue past the end-points using the slope of the two lowermost or uppermost points in the curve.
Zero	Continue past the end-points using a slope of 0.

Metric

enum gridpp::Metric

Binary verification metrics.

Enumerator
Ets	Equitable threat score.
Ts	Threat score.
Kss	Hannsen-Kuiper skill score.
Pc	Proportion correct.
Bias	Bias.
Hss	Heidke skill score.

Statistic

enum gridpp::Statistic

Statistical operations to reduce a vector to a scalar.

Enumerator
Mean	Mean of values.
Min	Minimum of values.
Median	Mean of values.
Max	Maximum of values.
Quantile	A quantile from values.
Std	Standard deviation of values.
Variance	Population variance of values.
Sum	Sum of values.
Unknown	Unknown statistic.

Function Documentation

apply_curve() [1/2]

vec gridpp::apply_curve	(	const vec &	fcst,
		const vec2 &	curve,
		gridpp::Extrapolation	policy_below,
		gridpp::Extrapolation	policy_above
	)

Apply arbitrary calibration curve to 1D forecasts.

Parameters

fcst	1D vector of forecast values
curve	Calibration curve
policy_below	Extrapolation policy below curve
policy_above	Extrapolation policy above curve

Returns

Calibrated forecasts

apply_curve() [2/2]

vec2 gridpp::apply_curve	(	const vec2 &	fcst,
		const vec2 &	curve,
		gridpp::Extrapolation	policy_below,
		gridpp::Extrapolation	policy_above
	)

Apply arbitrary calibration curve to 2D forecasts.

Parameters

fcst	2D grid of forecast values
curve	Calibration curve
policy_below	Extrapolation policy below curve
policy_above	Extrapolation policy above curve

Returns

Calibrated forecasts

bilinear() [1/2]

vec2 gridpp::bilinear	(	const Grid &	igrid,
		const Grid &	ogrid,
		const vec2	ivalues
	)

Bilinear downscaling grid to grid.

Parameters

igrid	Input grid
ogrid	Output grid to downscale to
ivalues	2D vector of values on the input grid

Returns

Values on the output grid

bilinear() [2/2]

vec gridpp::bilinear	(	const Grid &	igrid,
		const Points &	opoints,
		const vec2	ivalues
	)

Bilinear downscaling grid to points.

Parameters

igrid	Input grid
ogrid	Output points to downscale to
ivalues	2D vector of values on the input grid

Returns

Values for the output points

calc_even_quantiles()

vec gridpp::calc_even_quantiles	(	const vec &	values,
		int	num
	)

Get reasonably spaced quantiles from a vector of values, ignoring duplicate values but including the first number after duplicated values.

Include the lowest and highest values.

Parameters

values	vector of values (unsorted, and no invalid values)
num	number of thresholds to get

calc_gradient()

vec2 gridpp::calc_gradient	(	const Grid &	grid,
		const vec2 &	base,
		const vec2 &	values,
		int	radius,
		int	min_num = 2,
		float	min_range = 0,
		float	default_gradient = 0
	)

Computes gradients based on values in neighbourhood.

Parameters

grid	Grid
base	Dependent variable. Missing values are not used.
values	Independent variable. Missing values are not used.
radius	Neighbourhood radius in number of gridpoints
min_nim	Minimum number of points required to compute gradient
min_range	Minimum range of base to compute gradient
default_gradient	Use this gradient if minimum number is not met

calc_quantile() [1/2]

float gridpp::calc_quantile	(	const vec &	array,
		float	quantile
	)

calc_quantile() [2/2]

vec gridpp::calc_quantile	(	const vec2 &	array,
		float	quantile = MV
	)

calc_score() [1/3]

float gridpp::calc_score	(	float	a,
		float	b,
		float	c,
		float	d,
		gridpp::Metric	metric
	)

calc_score() [2/3]

float gridpp::calc_score	(	const vec &	ref,
		const vec &	fcst,
		float	threshold,
		gridpp::Metric	metric
	)

calc_score() [3/3]

float gridpp::calc_score	(	const vec &	ref,
		const vec &	fcst,
		float	threshold,
		float	fthreshold,
		gridpp::Metric	metric
	)

calc_statistic() [1/2]

float gridpp::calc_statistic	(	const vec &	array,
		gridpp::Statistic	statistic
	)

calc_statistic() [2/2]

vec gridpp::calc_statistic	(	const vec2 &	array,
		gridpp::Statistic	statistic
	)

clock()

double gridpp::clock

(

)

compatible_size() [1/2]

bool gridpp::compatible_size	(	const Grid &	grid,
		const vec2 &	v
	)

Check if the grid is the same size as the 2D vector.

compatible_size() [2/2]

bool gridpp::compatible_size	(	const Grid &	grid,
		const vec3 &	v
	)

correction() [1/2]

vec2 gridpp::correction	(	const Grid &	rgrid,
		const vec2 &	rvalues,
		const Points &	npoints,
		const vec &	nvalues,
		float	mean_radius,
		float	outer_radius,
		float	inner_radius,
		int	min_num,
		int	max_num,
		gridpp::CorrectionType	type,
		ivec2 &	count
	)

correction() [2/2]

vec2 gridpp::correction	(	const Grid &	rgrid,
		const vec3 &	rvalues,
		const Points &	npoints,
		const vec2 &	nvalues,
		const vec2 &	apply_values,
		float	mean_radius,
		float	outer_radius,
		float	inner_radius,
		int	min_num,
		int	max_num,
		gridpp::CorrectionType	type,
		ivec2 &	count
	)

count() [1/2]

vec gridpp::count	(	const Grid &	grid,
		const Points &	points,
		float	radius
	)

For each point, counts the number of gridpoints within the radius.

Parameters

grid	Grid
points	Points
radius	Radius [m]

Returns

Number of gridpoints

count() [2/2]

vec2 gridpp::count	(	const Points &	points,
		const Grid &	grid,
		float	radius
	)

For each gridpoint, counts the number of points within the radius.

Parameters

grid	Grid
points	Points
radius	Radius [m]

Returns

Number of points

debug()

void gridpp::debug

(

std::string

string

)

dewpoint() [1/2]

float gridpp::dewpoint	(	float	temperature,
		float	relative_humidity
	)

Calculate dewpoint temperature from temperature and relative humidity.

Parameters

temperature	Temperature [K]
relative_humidity	Relative humidity [1]

Returns

Dewpoint temperature [K]

dewpoint() [2/2]

vec gridpp::dewpoint	(	const vec &	temperature,
		const vec &	relative_humidity
	)

Vector version of dewpoint calculation.

Parameters

temperature	Temperatures [K]
relative_humidity	Relative humidities [1]

Returns

Dewpoint temperatures [K]

distance() [1/3]

vec gridpp::distance	(	const Grid &	grid,
		const Points &	points,
		int	num = 1
	)

For each point, calculates the distance to nearest gridpoint.

Parameters

grid	Grid
points	Points
num	Number of points

Returns

Distance [m] to nearest gridpoint for each point

distance() [2/3]

vec2 gridpp::distance	(	const Grid &	igrid,
		const Grid &	ogrid,
		int	num = 1
	)

For each output gridpoint, calculate the distance to nearest input gridpoint.

Parameters

grid	Grid
ogrid	Output grid
num	Number of points

Returns

Distance [m] to nearest gridpoint for each gridpoint

distance() [3/3]

vec2 gridpp::distance	(	const Points &	points,
		const Grid &	grid,
		int	num = 1
	)

For each gridpoint, calculates the distance to nearest point.

Parameters

points	Points
grid	Grid
num	Number of points

Returns

Distance [m] to nearest gridpoint for each point

error()

void gridpp::error

(

std::string

string

)

fill()

vec2 gridpp::fill	(	const Grid &	igrid,
		const vec2 &	input,
		const Points &	points,
		const vec &	radii,
		float	value,
		bool	outside
	)

Fill in values inside or outside a set of circles.

Parameters

input	Deterministic values with dimensions Y, X
radii	Circle radii for each point
value	Fill in this value
outside	if True, fill outside circles, if False, fill inside circles

fill_missing()

vec2 gridpp::fill_missing

(

const vec2 &

values

)

Fill in missing values based on nearby values.

Parameters

values

2D array of values

Returns

2D array of values without any missing values

future_deprecation_warning()

void gridpp::future_deprecation_warning	(	std::string	function,
		std::string	other = ""
	)

get_lower_index()

int gridpp::get_lower_index	(	float	iX,
		const std::vector< float > &	iValues
	)

Find the index in a vector that is equal or just below a value.

Parameters

iX	Lookup value
iValues	Lookup vector. Must be sorted.

Returns

The index into iValues that is equal or just below iX

get_neighbourhood_thresholds() [1/2]

vec gridpp::get_neighbourhood_thresholds	(	const vec2 &	input,
		int	num_thresholds
	)

Calculate appropriate approximation thresholds for neighbourhood quantile.

Parameters

input	2D (Y, X) array of values
num_thresholds	Number of thresholds

get_neighbourhood_thresholds() [2/2]

vec gridpp::get_neighbourhood_thresholds	(	const vec3 &	input,
		int	num_thresholds
	)

Calculate appropriate approximation thresholds for neighbourhood quantile based on an * ensemble.

Parameters

input	3D (Y, X, T) array of values
num_thresholds	Number of thresholds

get_optimal_threshold()

float gridpp::get_optimal_threshold	(	const vec &	ref,
		const vec &	fcst,
		float	threshold,
		gridpp::Metric	metric
	)

get_statistic()

gridpp::Statistic gridpp::get_statistic

(

std::string

name

)

Convert name of a statistic enum.

get_upper_index()

int gridpp::get_upper_index	(	float	iX,
		const std::vector< float > &	iValues
	)

Find the index in a vector that is equal or just above a value.

Parameters

iX	Lookup value
iValues	Lookup vector. Must be sorted.

Returns

The index into iValues that is equal or just above iX

gridding()

vec2 gridpp::gridding	(	const Grid &	grid,
		const Points &	points,
		const vec &	values,
		float	radius,
		int	min_num,
		gridpp::Statistic	statistic
	)

Aggregate points onto a grid.

Writes MV where there are not enough observations

Parameters

grid	Grid to aggregate to
points	Points with values
values	Values at points
radius	Circle radius for aggregate points [m]
min_num	Minimum number of points in radius to create a value
statistic	Statistic to compute on points within radius

init_ivec2()

ivec2 gridpp::init_ivec2	(	int	Y,
		int	X,
		int	value
	)

Initialize a vector of size Y, X, with a given value.

init_ivec3()

ivec3 gridpp::init_ivec3	(	int	Y,
		int	X,
		int	E,
		int	value
	)

Initialize a vector of size Y, X, E, with a given value.

init_vec2()

vec2 gridpp::init_vec2	(	int	Y,
		int	X,
		float	value = MV
	)

init_vec3()

vec3 gridpp::init_vec3	(	int	Y,
		int	X,
		int	E,
		float	value = MV
	)

initialize_omp()

void gridpp::initialize_omp

(

)

Sets the number of OpenMP threads to 1 if OMP_NUM_THREADS undefined.

interpolate()

float gridpp::interpolate	(	float	x,
		const std::vector< float > &	iX,
		const std::vector< float > &	iY
	)

Piecewise linear interpolation If x is outside the range of iX, then the min/max value of iY is used.

Parameters

x	Interpolation to this point
iX	Vector of x-axis values. Vector must be sorted.
iY	Vector of y-axis values corresponding to iX.

Returns

Y value corresponding to x

is_valid()

bool gridpp::is_valid

(

float

value

)

metric_optimizer_curve()

vec2 gridpp::metric_optimizer_curve	(	const vec &	ref,
		const vec &	fcst,
		const vec &	thresholds,
		gridpp::Metric	metric
	)

Create calibration curve that optimizes a metric.

Parameters

ref	Reference values (observations)
fcst	Forecast values
thresholds	Thresholds for computing optimal values for
metric	A Metric to optimize for

Returns

Calibration curve

monotonize_curve()

vec2 gridpp::monotonize_curve

(

vec2

curve

)

Ensure calibration curve is monotonic, by removing points.

Parameters

curve

Calibration curve

Returns

Monotonic calibration curve

nearest() [1/4]

vec2 gridpp::nearest	(	const Grid &	igrid,
		const Grid &	ogrid,
		const vec2	ivalues
	)

Nearest neighbour dowscaling grid to grid.

Parameters

igrid	Input grid
ogrid	Output grid to downscale to
ivalues	2D vector of values on the input grid

Returns

Values on the output grid

nearest() [2/4]

vec3 gridpp::nearest	(	const Grid &	igrid,
		const Grid &	ogrid,
		const vec3	ivalues
	)

nearest() [3/4]

vec gridpp::nearest	(	const Grid &	igrid,
		const Points &	opoints,
		const vec2	ivalues
	)

Nearest neighbour dowscaling grid to point.

Parameters

igrid	Input grid
ogrid	Output points to downscale to
ivalues	2D vector of values on the input grid

Returns

Values for the output points

nearest() [4/4]

vec2 gridpp::nearest	(	const Grid &	igrid,
		const Points &	opoints,
		const vec3	ivalues
	)

neighbourhood() [1/2]

vec2 gridpp::neighbourhood	(	const vec2 &	input,
		int	halfwidth,
		gridpp::Statistic	statistic
	)

Spatial neighbourhood filter, computing a statistic for a sliding square window.

Parameters

input	2D grid of values
halfwidth	Filter halfwidth in number of gridpoints
statistic	Statistic to compute

neighbourhood() [2/2]

vec2 gridpp::neighbourhood	(	const vec3 &	input,
		int	halfwidth,
		gridpp::Statistic	statistic
	)

Spatial neighbourhood filter for an ensemble of fields.

Parameters

input	3D grid of values with dimensions (Y, X, E)
halfwidth	Filter halfwidth in number of gridpoints
statistic	Statistic to compute

neighbourhood_brute_force() [1/2]

vec2 gridpp::neighbourhood_brute_force	(	const vec2 &	input,
		int	halfwidth,
		gridpp::Statistic	statistic
	)

Spatial neighbourhood filter without any shortcuts.

This is quite slow and is only useful for testing.

Parameters

input	2D grid of values
halfwidth	Filter halfwidth in number of gridpoints
operation	one of min, mean, median, max

neighbourhood_brute_force() [2/2]

vec2 gridpp::neighbourhood_brute_force	(	const vec3 &	input,
		int	halfwidth,
		gridpp::Statistic	statistic
	)

Spatial neighbourhood filter without any shortcuts.

This is quite slow and is only useful for testing.

Parameters

input	3D grid of values with dimensions (Y, X, E)
halfwidth	Filter halfwidth in number of gridpoints
operation	one of min, mean, median, max

neighbourhood_ens()

vec2 gridpp::neighbourhood_ens	(	const vec3 &	input,
		int	halfwidth,
		gridpp::Statistic	statistic
	)

Deprecated: Compute neighbourhood statistic on ensemble field.

Deprecated:

Use neighbourhood() function

neighbourhood_quantile() [1/2]

vec2 gridpp::neighbourhood_quantile	(	const vec2 &	input,
		float	quantile,
		int	halfwidth
	)

Computes a quantile in a sliding square neighbourhood.

Parameters

input	2D grid of values
quantile	Quantile to compute (between 0 and 1)
halfwidth	Filter halfwidth in number of gridpoints

neighbourhood_quantile() [2/2]

vec2 gridpp::neighbourhood_quantile	(	const vec3 &	input,
		float	quantile,
		int	halfwidth
	)

Computes a quantile in a sliding square neighbourhood for an ensemble of fields.

Parameters

input	3D grid of values with dimensions (Y, X, E)
quantile	Quantile to compute (between 0 and 1)
halfwidth	Filter halfwidth in number of gridpoints

neighbourhood_quantile_ens()

vec2 gridpp::neighbourhood_quantile_ens	(	const vec3 &	input,
		float	quantile,
		int	halfwidth
	)

Deprecated: Compute neighbourhood quantiles on ensemble field.

Deprecated:

Use neighbourhood_quantile() function

neighbourhood_quantile_ens_fast()

vec2 gridpp::neighbourhood_quantile_ens_fast	(	const vec3 &	input,
		float	quantile,
		int	radius,
		const vec &	thresholds
	)

Deprecated: Compute neighbourhood quantiles fast on ensemble field.

Deprecated:

Use neighbourhood_quantile_fast() function

neighbourhood_quantile_fast() [1/4]

vec2 gridpp::neighbourhood_quantile_fast	(	const vec2 &	input,
		float	quantile,
		int	halfwidth,
		const vec &	thresholds
	)

Fast and approximate neighbourhood quantile.

Parameters

input	2D grid of values
quantile	Quantile to compute (between 0 and 1)
halfwidth	Filter halfwidth in number of gridpoints
thresholds	Vector of thresholds to use to approximate value

neighbourhood_quantile_fast() [2/4]

vec2 gridpp::neighbourhood_quantile_fast	(	const vec3 &	input,
		float	quantile,
		int	halfwidth,
		const vec &	thresholds
	)

Fast and approximate neighbourhood quantile for ensemble of fields.

Parameters

input	3D grid of values with dimensions (Y, X, E)
quantile	Quantile to compute (between 0 and 1)
halfwidth	Filter halfwidth in number of gridpoints
thresholds	Vector of thresholds to use to approximate value

neighbourhood_quantile_fast() [3/4]

vec2 gridpp::neighbourhood_quantile_fast	(	const vec2 &	input,
		const vec2 &	quantile,
		int	halfwidth,
		const vec &	thresholds
	)

Fast and approximate neighbourhood quantile, with spatially varying quantile.

Parameters

input	2D grid of values
quantile	2D grid quantiles to compute (between 0 and 1)
halfwidth	Filter halfwidth in number of gridpoints
thresholds	Vector of thresholds to use to approximate value

neighbourhood_quantile_fast() [4/4]

vec2 gridpp::neighbourhood_quantile_fast	(	const vec3 &	input,
		const vec2 &	quantile,
		int	halfwidth,
		const vec &	thresholds
	)

Fast and approximate neighbourhood quantile for ensemble of fields, with spatially varying quantile.

Parameters

input	3D grid of values with dimensions (Y, X, E)
quantile	2D grid quantiles to compute (between 0 and 1)
halfwidth	Filter halfwidth in number of gridpoints
thresholds	Vector of thresholds to use to approximate value

num_missing_values()

int gridpp::num_missing_values

(

const vec2 &

iArray

)

optimal_interpolation() [1/2]

vec2 gridpp::optimal_interpolation	(	const Grid &	bgrid,
		const vec2 &	background,
		const Points &	points,
		const vec &	pobs,
		const vec &	pratios,
		const vec &	pbackground,
		const StructureFunction &	structure,
		int	max_points
	)

Optimal interpolation for a deterministic gridded field.

Parameters

bgrid	Grid of background field
background	2D field of background values
points	Points of observations
pobs	Vector of observations
pratios	Vector of ratio of observation error variance to background variance
pbackground	Background with observation operator
structure	Structure function
max_points	Maximum number of observations to use inside localization zone; Use 0 to disable

optimal_interpolation() [2/2]

vec gridpp::optimal_interpolation	(	const Points &	bpoints,
		const vec &	background,
		const Points &	points,
		const vec &	pobs,
		const vec &	pratios,
		const vec &	pbackground,
		const StructureFunction &	structure,
		int	max_points
	)

Optimal interpolation for a deterministic vector of points.

Parameters

bpoints	Points of background field
background	1D field of background values
points	Points of observations
pobs	Vector of observations
pratios	Vector of ratio of observation error variance to background variance
pbackground	Background with observation operator
structure	Structure function
max_points	Maximum number of observations to use inside localization zone; Use 0 to disable

optimal_interpolation_ensi() [1/2]

vec3 gridpp::optimal_interpolation_ensi	(	const Grid &	bgrid,
		const vec3 &	background,
		const Points &	points,
		const vec &	pobs,
		const vec &	psigmas,
		const vec2 &	pbackground,
		const StructureFunction &	structure,
		int	max_points
	)

Optimal interpolation using a structure function based on an ensemble See Lussana et al 2019 (DOI: 10.1002/qj.3646)

Parameters

input	3D field of background values (Y, X, E)
bgrid	grid corresponding to input
pobs	vector of observations
pci	vector of ci values
points	observation points

optimal_interpolation_ensi() [2/2]

vec2 gridpp::optimal_interpolation_ensi	(	const Points &	bpoints,
		const vec2 &	background,
		const Points &	points,
		const vec &	pobs,
		const vec &	psigmas,
		const vec2 &	pbackground,
		const StructureFunction &	structure,
		int	max_points
	)

optimal_interpolation_transform() [1/2]

vec2 gridpp::optimal_interpolation_transform	(	const Grid &	bgrid,
		const vec2 &	background,
		float	bsigma,
		const Points &	points,
		const vec &	pobs,
		const vec &	psigmas,
		const vec &	pbackground,
		const StructureFunction &	structure,
		int	max_points,
		const Transform &	transform
	)

This is its own function because the variance parameterization is different than in the non-transformed case.

optimal_interpolation_transform() [2/2]

vec gridpp::optimal_interpolation_transform	(	const Points &	bpoints,
		const vec &	background,
		float	bsigma,
		const Points &	points,
		const vec &	pobs,
		const vec &	psigmas,
		const vec &	pbackground,
		const StructureFunction &	structure,
		int	max_points,
		const Transform &	transform
	)

point_in_rectangle()

bool gridpp::point_in_rectangle	(	const Point &	A,
		const Point &	B,
		const Point &	C,
		const Point &	D,
		const Point &	m
	)

Checks if a point is located inside a rectangle formed by 4 points.

The 4 points must be provided in an order that draws out a rectangle (either clockwise or counter-clockwise)

Parameters

A	A point in the rectangle
B	A point in the rectangle
C	A point in the rectangle
D	A point in the rectangle
m	The point to test if it is inside

Returns

True if the point is inside, False otherwise

pressure() [1/2]

float gridpp::pressure	(	float	ielev,
		float	oelev,
		float	ipressure,
		float	itemperature = 288.15
	)

Calculate pressure at a new elevation.

Parameters

ielev	Elevation at start point
oelev	Elevation at new point
ipressure	Pressure at start point
itemperature	Temperature at start point

Returns

Pressure at new point

pressure() [2/2]

vec gridpp::pressure	(	const vec &	ielev,
		const vec &	oelev,
		const vec &	ipressure,
		const vec &	itemperature
	)

Calculate Vector version of pressure calculation.

Parameters

ielev	Elevations at start point
oelev	Elevations at new point
ipressure	Pressures at start point
itemperature	Temperatures at start point

Returns

Pressures at new points

qnh() [1/2]

float gridpp::qnh	(	float	pressure,
		float	altitude
	)

Diagnose QNH from pressure and altitude.

Parameters

pressure	Pressure at point [pa]
altitude	Altitude of point [m]

Returns

QNH [pa]

qnh() [2/2]

vec gridpp::qnh	(	const vec &	pressure,
		const vec &	altitude
	)

Vector version of QNH calculation.

Parameters

pressure	Pressures at points [pa]
altitude	Altitudes of points [m]

Returns

QNH [pa]

quantile_mapping_curve()

vec2 gridpp::quantile_mapping_curve	(	const vec &	ref,
		const vec &	fcst,
		vec	quantiles = vec()
	)

Create quantile mapping calibration curve.

Parameters

ref	Reference values (observations)
fcst	Forecast values
quantiles	Vector of quantiles to extract. If empty, use all values.

Returns

Calibration curve

relative_humidity() [1/2]

float gridpp::relative_humidity	(	float	temperature,
		float	dewpoint
	)

Calculate relative humidity from temperature and dewpoint temperature.

Parameters

temperature	Temperature [K]
dewpoint	Dewpoint temperature [K]

Returns

Relative humidity [1]

relative_humidity() [2/2]

vec gridpp::relative_humidity	(	const vec &	temperature,
		const vec &	dewpoint
	)

Vector version of relative humidity calculation.

Parameters

temperature	Temperatures [K]
dewpoint	Dewpoint temperatures [K]

Returns

Relative humidities [1]

set_omp_threads()

void gridpp::set_omp_threads

(

int

num

)

Set the number of OpenMP threads to use.

Overwrides OMP_NUM_THREAD env variable.

simple_gradient() [1/2]

vec2 gridpp::simple_gradient	(	const Grid &	igrid,
		const Grid &	ogrid,
		const vec2	ivalues,
		float	elev_gradient
	)

simple_gradient() [2/2]

vec gridpp::simple_gradient	(	const Grid &	igrid,
		const Points &	opoints,
		const vec2	ivalues,
		float	elev_gradient
	)

smart()

vec2 gridpp::smart	(	const Grid &	igrid,
		const Grid &	ogrid,
		const vec2 &	ivalues,
		int	num,
		const StructureFunction &	structure
	)

Smart neighbour downscaling grid to grid.

Parameters

igrid	Input grid
ogrid	Output points to downscale to
ivalues	2D vector of values on the input grid
num	Number of neighbours to average
structure	Structure function for determining similarity

Returns

Values for the output points

test_array()

float * gridpp::test_array	(	float *	v,
		int	n
	)

Special function whose presense is needed for SWIG.

test_ivec2_output()

ivec2 gridpp::test_ivec2_output

(

)

test_ivec3_output()

ivec3 gridpp::test_ivec3_output

(

)

test_ivec_input()

int gridpp::test_ivec_input

(

const ivec &

input

)

Testing function for 1D input vector.

test_ivec_output()

ivec gridpp::test_ivec_output

(

)

test_not_implemented_exception()

void gridpp::test_not_implemented_exception

(

)

test_vec2_argout()

float gridpp::test_vec2_argout

(

vec2 &

distances

)

Testing function for 2D vector treated as output.

test_vec2_input()

float gridpp::test_vec2_input

(

const vec2 &

input

)

Testing function for 2D input vector.

test_vec2_output()

vec2 gridpp::test_vec2_output

(

)

Testing function for 2D output vector.

test_vec3_input()

float gridpp::test_vec3_input

(

const vec3 &

input

)

Testing function for 3D input vector.

test_vec3_output()

vec3 gridpp::test_vec3_output

(

)

Testing function for 3D output vector.

test_vec_argout()

float gridpp::test_vec_argout

(

vec &

distances

)

Testing function for 1D vector treated as output.

test_vec_input()

float gridpp::test_vec_input

(

const vec &

input

)

Testing function for 1D input vector.

test_vec_output()

vec gridpp::test_vec_output

(

)

Testing function for 1D output vector.

version()

std::string gridpp::version

(

)

The gridpp version.

Returns

The gridpp version

warning()

void gridpp::warning

(

std::string

string

)

wetbulb() [1/2]

float gridpp::wetbulb	(	float	temperature,
		float	pressure,
		float	relative_humidity
	)

Calculate wetbulb temperature from temperature, pressure, and relative humidity.

Parameters

temperature	Temperature [K]
pressure	Air pressure [pa]
Relative	humidity [1]

Returns

Wetbulb temperature [K]

wetbulb() [2/2]

vec gridpp::wetbulb	(	const vec &	temperature,
		const vec &	pressure,
		const vec &	relative_humidity
	)

Vector version of wetbulb calculation.

Parameters

temperature	Temperatures [K]
pressure	Air pressures [pa]
Relative	humidities [1]

Returns

Wetbulb temperatures [K]

wind_direction() [1/2]

float gridpp::wind_direction	(	float	xwind,
		float	ywind
	)

Diagnose wind direction from its components.

If both xwind and ywind are 0, then direction is 180

Parameters

xwind	X-component of wind [any unit]
ywind	Y-component of wind [any unit]

Returns

Wind direction [degrees]

wind_direction() [2/2]

vec gridpp::wind_direction	(	const vec &	xwind,
		const vec &	ywind
	)

Vector version of wind direction calculation.

Parameters

xwind	X-components of wind [any unit]
ywind	Y-components of wind [any unit]

Returns

Wind direction [degrees]

wind_speed() [1/2]

float gridpp::wind_speed	(	float	xwind,
		float	ywind
	)

Diagnose wind speed from its components.

Parameters

xwind	X-component of wind [any unit]
ywind	Y-component of wind [any unit]

Returns

Wind speed [any unit]

wind_speed() [2/2]

vec gridpp::wind_speed	(	const vec &	xwind,
		const vec &	ywind
	)

Vector version of wind speed calculation.

Parameters

xwind	X-components of wind [any unit]
ywind	Y-components of wind [any unit]

Returns

Wind speeds [any unit]

Variable Documentation

MV

const float gridpp::MV = NAN

static

Missing value indicator.

MV_CML

const float gridpp::MV_CML = -999

static

Missing value indicator in gridpp command-line tool.

pi

const float gridpp::pi = 3.14159265

static

Mathematical constant pi.

radius_earth

const double gridpp::radius_earth = 6.378137e6

static

Radius of the earth [m].

swig_default_value

const float gridpp::swig_default_value = -1

static

Default value used to fill array in SWIG testing functions.

Not useful for any other purpose.