Source code for ladybug_radiance.study.radiation

"""Class for visualizing incident radiation (or irradiance) falling onto a mesh."""
from __future__ import division

try:  # first, assume we are in cPython and numpy is installed
    from typing import Tuple
    import numpy as np
except Exception:  # we are in IronPython or numpy is not installed
    np, Tuple = None, None

from ladybug_geometry.bounding import bounding_box
from ladybug_geometry.geometry3d import Mesh3D, Face3D
from ladybug.datatype.energyintensity import Radiation
from ladybug.datatype.energyflux import Irradiance
from ladybug.graphic import GraphicContainer
from ladybug.legend import LegendParameters
from ladybug.color import Colorset

from ..intersection import sky_intersection_matrix


[docs] class RadiationStudy(object): """Visualize the incident radiation (or irradiance) falling onto a study_mesh. Such studies of incident radiation can be used to approximate the energy that can be collected from photovoltaic or solar thermal systems. They are also useful for evaluating the impact of a building's orientation on both energy use and the size/cost of cooling systems. For studies of photovoltaic potential or building energy use impact, a sky matrix from EPW radiation should be used. For studies of cooling system size/cost, a sky matrix derived from the STAT file's clear sky radiation should be used. Not that no reflections of solar energy are included in the analysis performed by this class. Ground reflected irradiance is crudely accounted for by means of an emissive "ground hemisphere," which is like the sky dome hemisphere and is derived from the ground reflectance that is associated with the connected sky_matrix. This means that including geometry that represents the ground surface will effectively block such crude ground reflection. Args: sky_matrix: A SkyMatrix object, which describes the radiation coming from the various patches of the sky. study_mesh: A ladybug geometry Mesh3D, which represents the geometry on which the incident radiation is being studied. context_geometry: A list of ladybug geometry Face3D and/or Mesh3D that can block the view to the sky and ground. offset_distance: An optional number to offset the sensor points before the vectors are cast through the context_geometry. (Default: 0). by_vertex: A boolean to indicate whether the study should be run for each vertex of the study_mesh (True) or each face of the study mesh (False). (Default: False). sim_folder: An optional path to a folder where the simulation files will be written. If None, a temporary directory will be used. (Default: None). use_radiance_mesh: A boolean to note whether input Mesh3D should be translated to Radiance Meshes for simulation or whether they should simply have their faces translated to Radiance polygons. For complex context geometry, Radiance meshes will use less memory but they take a longer time to prepare compared to polygons. (Default: False). Properties: * sky_matrix * study_mesh * context_geometry * offset_distance * by_vertex * sim_folder * use_radiance_mesh * study_points * study_normals * intersection_matrix * radiation_values * irradiance_values * metadata * is_benefit """ __slots__ = ( '_metadata', '_is_benefit', '_sky_matrix', '_study_mesh', '_context_geometry', '_offset_distance', '_by_vertex', '_study_points', '_study_normals', '_sim_folder', '_use_radiance_mesh', '_intersection_matrix', '_radiation_values') def __init__( self, sky_matrix, study_mesh, context_geometry, offset_distance=0, by_vertex=False, sim_folder=None, use_radiance_mesh=False): """Initialize RadiationStudy.""" # set default values, which will be overwritten when the study is run self._offset_distance = float(offset_distance) self._by_vertex = bool(by_vertex) # set the key properties of the object self.sky_matrix = sky_matrix self.study_mesh = study_mesh self.context_geometry = context_geometry self.sim_folder = sim_folder self.use_radiance_mesh = use_radiance_mesh # set default values, which will be overwritten when the study is run self._intersection_matrix = None self._radiation_values = None @property def sky_matrix(self): """Get or set a SkyMatrix object for the sky used in the study.""" return self._sky_matrix @sky_matrix.setter def sky_matrix(self, value): self._sky_matrix = value self._metadata, direct, diffuse = value.data self._is_benefit = True if hasattr(value, 'benefit_matrix') and \ value.benefit_matrix is not None else False self._radiation_values = None @property def study_mesh(self): """Get or set a SkyMatrix object for the sky used in the study.""" return self._study_mesh @study_mesh.setter def study_mesh(self, value): assert isinstance(value, Mesh3D), 'Expected Mesh3D for RadiationStudy ' \ 'study_mesh. Got {}.'.format(type(value)) self._study_mesh = value self._reset_points() @property def context_geometry(self): """Get or set a tuple of Face3D and Mesh3D for the geometry that can block sun. """ return self._context_geometry @context_geometry.setter def context_geometry(self, value): if not isinstance(value, tuple): try: value = tuple(value) except (ValueError, TypeError): raise ValueError('Expected tuple or list for context_geometry. ' 'Got {}.'.format(type(value))) for geo in value: assert isinstance(geo, (Face3D, Mesh3D)), 'Expected Face3D or Mesh3D for ' \ 'RadiationStudy context_geometry. Got {}.'.format(type(geo)) self._context_geometry = value self._intersection_matrix = None self._radiation_values = None @property def offset_distance(self): """Get or set a number for the offset distance used in the study.""" return self._offset_distance @offset_distance.setter def offset_distance(self, value): assert isinstance(value, (float, int)), \ 'Expected number for offset_distance. Got {}.'.format(type(value)) self._offset_distance = value self._reset_points() @property def by_vertex(self): """Get or set a boolean for whether the study should be run for each vertex.""" return self._by_vertex @by_vertex.setter def by_vertex(self, value): self._by_vertex = bool(value) self._reset_points() @property def sim_folder(self): """Get or set text for the path where the simulation files are written.""" return self._sim_folder @sim_folder.setter def sim_folder(self, value): if value is not None: assert isinstance(value, str), 'Expected file path string for sim_folder. ' \ 'Got {}.'.format(type(value)) self._sim_folder = value @property def use_radiance_mesh(self): """Get or set a boolean for whether Radiance Meshes are used in the simulation. """ return self._use_radiance_mesh @use_radiance_mesh.setter def use_radiance_mesh(self, value): self._use_radiance_mesh = bool(value) @property def study_points(self): """Get a tuple of Point3Ds for the points of the study.""" return self._study_points @property def study_normals(self): """Get a tuple of Vector3Ds for the normals of the study.""" return self._study_normals @property def intersection_matrix(self): """Get a list of lists for the intersection matrix computed by the study.""" if self._intersection_matrix is None: self._compute_intersection_matrix() return self._intersection_matrix @property def radiation_values(self): """Get a list of values for the radiation results of the study in kWh/m2.""" if self._radiation_values is None: self.compute() return self._radiation_values @property def irradiance_values(self): """Get a list of values for the irradiance results of the study in W/m2.""" factor = 1000 / self.sky_matrix.wea_duration \ if hasattr(self.sky_matrix, 'wea_duration') else \ 1000 / (((self.metadata[3] - self.metadata[2]).total_seconds() / 3600) + 1) return [r * factor for r in self.radiation_values] @property def metadata(self): """Get a tuple of information about the metadata assigned to the study.""" return self._metadata @property def is_benefit(self): """Get a boolean to note whether the sky matrix includes benefit information.""" return self._is_benefit
[docs] def total_radiation(self, conversion_to_meters=1): """Get a number for the total radiation of the study in kWh. Note that, when the study is run by_vertex, it is assumed that all vertices represent the same area. Args: conversion_to_meters: A number (typically less than 1) to note the conversion factor from the mesh area to square meters. This should be a conversion in square units and not just linear units. (Default: 1). """ if self.by_vertex: full_area = self.study_mesh.area * conversion_to_meters total = sum(self.radiation_values) / full_area else: total = 0 for rad, area in zip(self.radiation_values, self._study_mesh.face_areas): total += rad * area * conversion_to_meters return total
[docs] def compute(self): """Compute the radiation values of the study. Note that this method is automatically called under the hood when accessing any results of the study and these results have not already been computed. So using this method is not necessary to correctly use this class. However, explicitly calling this method can help control when the time consuming part of the study runs, which is particularly helpful for larger studies. """ # compute the intersection matrix if self._intersection_matrix is None: self._compute_intersection_matrix() # get the total radiation from the sky matrix mtx = self.sky_matrix.data if np is None: # perform the calculation with float numbers sky_rad = [dir_rad + dif_rad for dir_rad, dif_rad in zip(mtx[1], mtx[2])] grd_val = (sum(sky_rad) / len(sky_rad)) * self.sky_matrix.ground_reflectance ground_rad = [grd_val] * len(sky_rad) all_rad = sky_rad + ground_rad self._radiation_values = [ sum(r * w for r, w in zip(pt_rel, all_rad)) for pt_rel in self._intersection_matrix ] else: # perform the calculation with numpy matrices sky_rad = np.array(mtx[1]) + np.array(mtx[2]) grd_val = (sky_rad.sum() / len(sky_rad)) * self.sky_matrix.ground_reflectance ground_rad = np.full(len(sky_rad), grd_val) all_rad = np.concatenate([sky_rad, ground_rad]) self._radiation_values = np.dot(self._intersection_matrix, all_rad).tolist()
[docs] def draw(self, legend_parameters=None, plot_irradiance=False): """Draw a colored study_mesh, compass, graphic/legend, and title. Args: legend_parameters: An optional LegendParameter object to change the display of the radiation study. If None, default legend parameters will be used. (Default: None). plot_irradiance: Boolean to note whether the results should be plotted with units of total Radiation (kWh/m2) [False] or with units of average Irradiance (W/m2) [True]. (Default: False). Returns: A tuple with three values. - colored_mesh -- A colored Mesh3D for the study results. - graphic -- A GraphicContainer for the colored mesh, indicating the legend and title location for the study. - title -- Text for the title of the study. """ # get the radiation data if plot_irradiance: d_type, unit, title = Irradiance(), 'W/m2', 'Incident Irradiance' rad_data = self.irradiance_values else: d_type, unit, title = Radiation(), 'kWh/m2', 'Incident Radiation' rad_data = self.radiation_values if self.is_benefit: title = '{} Benefit/Harm'.format(title) # override the legend default min and max to make sense for the radiation study if legend_parameters is not None: assert isinstance(legend_parameters, LegendParameters), \ 'Expected LegendParameters. Got {}.'.format(type(legend_parameters)) l_par = legend_parameters.duplicate() else: l_par = LegendParameters() if self.is_benefit: if l_par.min is None: l_par.min = min((min(rad_data), -max(rad_data))) if l_par.max is None: l_par.max = max((-min(rad_data), max(rad_data))) if l_par.are_colors_default: l_par.colors = reversed(Colorset.benefit_harm()) else: if l_par.min is None: l_par.min = 0 if l_par.max is None: l_par.max = max(rad_data) # create the mesh, graphic container, and title min_pt, max_pt = bounding_box((self.study_mesh,) + self.context_geometry) graphic = GraphicContainer( rad_data, min_pt, max_pt, l_par, d_type, unit) colored_mesh = self.study_mesh colored_mesh.colors = graphic.value_colors return colored_mesh, graphic, title
def _reset_points(self): """Reset the study points and normals used in the study.""" points = self._study_mesh.vertices if self._by_vertex else \ self._study_mesh.face_centroids normals = self._study_mesh.vertex_normals if self._by_vertex else \ self._study_mesh.face_normals if self._offset_distance != 0: points = tuple( pt.move(vec * self._offset_distance) for pt, vec in zip(points, normals)) self._study_points = points self._study_normals = normals self._intersection_matrix = None self._radiation_values = None def _compute_intersection_matrix(self): """Compute intersection matrix.""" self._intersection_matrix = sky_intersection_matrix( self.sky_matrix, self.study_points, self.study_normals, self.context_geometry, self.offset_distance, numericalize=True, sim_folder=self.sim_folder, use_radiance_mesh=self.use_radiance_mesh)
[docs] def ToString(self): """Overwrite .NET ToString.""" return self.__repr__()
def __len__(self): return len(self.study_points) def __repr__(self): """Radiation Study object representation.""" return 'RadiationStudy [{} values]'.format(len(self.study_points))