layer#

Layer Definitions#

struct PressureLayer#

A simple structure of two named floats that represent a pressure layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Public Functions

inline PressureLayer()#

Construct an empty sharp::PressureLayer.

Sets the top and bottom to sharp::MISSING

PressureLayer(float bot, float top, float delta = -1000.0)#

Constructs a sharp::PressureLayer.

Parameters:

  • bot – (bottom of layer, Pa)

  • top – (top of layer, Pa)

  • delta – (pressure increment, Pa)

Public Members

float bottom#

The bottom of the pressure layer (Pa)

float top#

The top of the pressure layer (Pa)

float delta#

The pressure interval with which to iterate over the layer (Pa)

Public Static Attributes

static constexpr LayerCoordinate coord = LayerCoordinate::pressure#

The coordinate system of the layer.

struct HeightLayer#

A simple structure of named floats that represent a height layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Public Functions

inline HeightLayer()#

Construct an empty sharp::HeightLayer.

Sets the top and bottom to sharp::MISSING

HeightLayer(float bot, float top, float delta = 100.0)#

Constructs a sharp::HeightLayer.

Parameters:

  • bot – (bottom of layer, meters)

  • top – (top of layer, meters)

  • delta – (height increment, meters)

Public Members

float bottom#

The bottom of the height layer (meters)

float top#

The top of the height layer (meters)

float delta#

The height interval with which to iterate over the layer (meters)

Public Static Attributes

static constexpr LayerCoordinate coord = LayerCoordinate::height#

The coordinate system of the layer.

struct LayerIndex#

A simple structure of two named integer indices for the top and bottom of a layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Public Members

std::ptrdiff_t kbot#

The array index of the bottom of the layer.

std::ptrdiff_t ktop#

The array index of the top of the layer.

Layer Conversions#

HeightLayer sharp::pressure_layer_to_height(PressureLayer layer, const float pressure[], const float height[], const std::ptrdiff_t N, const bool toAGL = false)#

Converts a sharp::PressureLayer to a sharp::HeightLayer.

Author

Kelton Halbert - NWS Storm Prediction Center

Converts a sharp::PressureLayer to a sharp::HeightLayer via interpolation, with the option of returning the layer in meters AGL or MSL. If for some strange reason you provide a PressureLayer that is out of the bounds of pressure[], then the bottom and top of the output layer will be set to sharp::MISSING.

Parameters:

  • layer – (Pa)

  • pressure – (Pa)

  • height – (meters)

  • N – (Length of arrays)

  • toAGL – Flag whether to return meters AGL or MSL (default: false)

Returns:

{bottom, top}

PressureLayer sharp::height_layer_to_pressure(HeightLayer layer, const float pressure[], const float height[], const std::ptrdiff_t N, const bool isAGL = false)#

Converts a sharp::HeightLayer to a sharp::PressureLayer.

Author

Kelton Halbert - NWS Storm Prediction Center

Converts a sharp::HeightLayer to a sharp::PressureLayer via interpolation, with a flag to signal whether the input layer is in meters AGL or meters MSL. If for some strange reason you provide a HeightLayer that is out of the bounds of height[], then the bottom and top of the output layer will be set to sharp::MISSING.

Parameters:

  • layer – (meters)

  • pressure – (Pa)

  • height – (meters)

  • N – (Length of arrays)

  • isAGL – Whether the input layer is AGL / MSL (default: false)

Returns:

{bottom, top}

LayerIndex sharp::get_layer_index(PressureLayer &layer, const float pressure[], const std::ptrdiff_t N)#

Finds the array indices corresponding to the given sharp::PressureLayer.

Author

Kelton Halbert - NWS Storm Prediction Center

Returns the array indices corresponding to the given sharp::PressureLayer, and performs bounds checking on the layer. As part of the bounds checking, the sharp::PressureLayer is modified if the bottom or top of the layer is out of bounds, which is why it gets passed as a reference.

If the exact values of the top and bottom of the layer are present, their indices are ignored. The default behavior is that the bottom and top of a layer is computed by interpolation by default, since it may or may not be present in the native data.

Parameters:

  • layer – {bottom, top}

  • pressure – (Pa)

  • N – (length of array)

Returns:

{kbot, ktop}

LayerIndex sharp::get_layer_index(HeightLayer &layer, const float height[], const std::ptrdiff_t N)#

Finds the array indices corresponding to the given sharp::HeightLayer.

Author

Kelton Halbert - NWS Storm Prediction Center

Returns the array indices corresponding to the given sharp::HeightLayer, and performs bounds checking on the layer. As part of the bounds checking, the sharp::HeightLayer is modified if the bottom or top of the layer is out of bounds, which is why it gets passed as a reference.

If the exact values of the top and bottom of the layer are present, their indices are ignored. The default behavior is that the bottom and top of a layer is computed by interpolation by default, since it may or may not be present in the native data.

Parameters:

  • layer – {bottom, top}

  • height – (meters)

  • N – (length of array)

Returns:

{kbot, ktop}

Layer Calculations#

template<typename L>
constexpr float sharp::layer_min(L layer, const float coord_arr[], const float data_arr[], const std::ptrdiff_t N, float *lvl_of_min = nullptr)#

Returns the minimum value in the given layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Returns the minimum value observed within the given data array over the given sharp::PressureLayer or sharp::HeightLayer. The function bounds checks the layer by calling sharp::get_layer_index.

If lvl_of_min is not a nullptr, then the pointer will be dereferenced and filled with the coordinate of the minimum value.

Parameters:

  • layer – (sharp::PressureLayer or sharp::HeightLayer)

  • coord_arr – (coordinate units; Pa or meters)

  • data_arr – (data array to find min on)

  • N – (length of arrays)

  • lvl_of_min – (level of min val)

Returns:

layer_min

template<typename L>
constexpr float sharp::layer_max(L layer, const float coord_arr[], const float data_arr[], const std::ptrdiff_t N, float *lvl_of_max = nullptr)#

Returns the maximim value in the given layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Returns the maximum value observed within the given data array over the given sharp::PressureLayer or sharp::HeightLayer. The function bounds checks the layer by calling sharp::get_layer_index.

If lvl_of_max is not a nullptr, then the pointer will be dereferenced and filled with the coordinate of the maximum value.

Parameters:

  • layer – (sharp::PressureLayer or sharp::HeightLayer)

  • coord_arr – (coordinate units; Pa or meters)

  • data_arr – (data array to find max on)

  • N – (length of arrays)

  • lvl_of_max – (level of max val)

Returns:

layer_max

float sharp::layer_mean(PressureLayer layer, const float pressure[], const float data_arr[], const std::ptrdiff_t N)#

Computes the mass-weighted mean value of a field over a given pressure layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Computes the mass-weighted mean value of given arrays of data and corresponding pressure coordinates over the given sharp::PressureLayer.

Parameters:

  • layer – (sharp::PressureLayer)

  • pressure – (vertical pressure array; Pa)

  • data_arr – (The data for which to compute a mean)

  • N – (length of pressure and data arrays)

Returns:

layer_mean

float sharp::layer_mean(HeightLayer layer, const float height[], const float pressure[], const float data_arr[], const std::ptrdiff_t N, const bool isAGL = false)#

Computes the mass-weighted mean value of a field over a given height layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Computes the mass-weighted mean value of given arrays of data and corresponding height coordinates over the given sharp::HeightLayer. This is really just a fancy wrapper around the implementation that uses sharp::PressureLayer.

Parameters:

  • layer – (sharp::HeightLayer)

  • height – (vertical height array; meters)

  • pressure – (vertical pressure array; Pa)

  • data_arr – (The data for which to compute a mean)

  • N – (length of pressure and data arrays)

  • isAGL – (whether or not intput is in AGL or MSL)

Returns:

layer_mean

template<typename L>
float sharp::integrate_layer_trapz(L layer, const float var_array[], const float coord_array[], const std::ptrdiff_t N, const int integ_sign = 0, const bool weighted = false)#

Returns a trapezoidal integration of the given layer.

Author

Kelton Halbert - NWS Storm Prediction Center

Returns a trapezoidal integration of the given data array over the given sharp::PressureLayer or sharp::HeightLayer. There is an additional default argument that determines whether this is a weighted average or not. The sign of the integration may be passed as well, i.e. integrating only positive or negative values, by passing a 1 or -1 to integ_sign.

Parameters:

  • layer – (sharp::PressureLayer or sharp::HeightLayer)

  • var_array – (data array to integrate)

  • coord_array – (coordinate array to integrate over)

  • N – (length of arrays)

  • weighted – (bool; default=false)

  • integ_sign – (int; default=0)

Returns:

integrated_value