pygplates column——Introduction——Find the reconstruction features of a certain geometric area

This example iterates over the reconstructed feature set, and then finds those features whose geometric region overlaps the target region.

sample code

import pygplates
# 加载rotations模型
rotations_model = pygplates.RotationsModel("rotations.rot")
# 加载特征
features = pygplates.FeatureCollection("features.gpml")
# 重建时间
reconstruction_time = 10
# 所有特征均检测与目标区域重叠
# 目标区域可以通过一系列（纬度，经度）点确定
polygon = pygplates.PolygonOnSphere([(0,0), (90,0), (0,90)])
# 重建特征至重建时间
reconstructed_features = []
pygplates.reconstruct(features, rotation_model, reconstructed_features, reconstruction_time, group_with_feature=True)
# 重建至10Ma时与目标区域重叠的特征
overlapping_features = []
# 遍历所有重建特征
for feature, feature_reconstructed_geometries in reconstructed_features:
	# 遍历当前特征的所有重建几何图形
	for feature_reconstructed_geometry in feature_reconstructed_geometries:
		# 获取当前重建几何图形至目标区域的最短距离
		# 将目标区域内部的距离视为0
		# 同样将重建几何图形的内部距离视为0
		min_distance_to_feature = pygplates.GeometryOnSphere.distance(
			polygon,
			feature_reconstructed_geometry.get_reconstructed_geometry(),
			geometry1_is_solid=True,
			geometry2_is_solid=True)
		# 当min_distance_to_feature=0表示重建的几何图形要么与目标区域相接，要么重叠（或者皆可）
		if min_distance_to_feature == 0:
			overlapping_feature.append(feature)
			# 结束当前特征的判断（避免多次添加）
			break
# 如果存在重叠特征，将它们写入文件
if overlapping_features:
	# 将所有重叠特征放到一个特征集合中
	overlapping_feature_collection = pygplates.FeatureCollection(overlapping_features)
	# 新建一个文件名
	overlapping_features_filename = "features_overlapping_at_{0}Ma.gpml".format(reconstruction_time)
	# 将特征集合写入新文件
	overlapping_feature_collection.write(overlapping_features_filename)

Detailed code

• Load the motion model from the rotation file intopygplates.RotationModelin class.

rotation_model = pygplates.RotationModel("rotations.rot")

• Load rebuildable plates intopygplates.FeatureCollectionin class.

features = pygplates.FeatureCollection("features.gpml")

• Specifies the rebuild time.

reconstruction_time = 10

• new target area

polygon = pygplates.PolygonOnSphere([(0,0), (90,0), (0,90)])

• usepygplates.reconstruct()Rebuild all plates to 10Ma. Specifies a storage list for reconstructed plate results.
  At the same time the parametergroup_with_featureSet asTrue, can guaranteereconstructed feature geometriesGroup by section.

reconstructed_features = []
pygplates.reconstruct(features, rotation_model, reconstructed_features, group_with_feature=True)

• reconstructed_featuredEach element in the list is a tuple containing a plate and all associated reconstruction geometry.

for feature, feature_reconstructed_geometries in reconstructed_features:

• Each plate can have multiple geometries and therefore can contain multiple reconstruction geometries.

for feature_reconstructed_geometry in feature_reconstructed_geometries:

• Use ==pygplates.GeometryOnSphere.distance() == to calculate the shortest distance between the target region and the reconstructed plate geometry.
  geometry1_is_solidSet to True in case the reconstructed geometry falls completely within the target area, in which case 0 is returned. If not set, the minimum distance will be 0 unless the borders of the two are exactly touching, otherwise it will never be 0.
  geometry2_is_solidSet to True to prevent the target region from falling completely within the reconstructed geometry. Also considered overlapping.

min_distance_to_feature = pygplates.GeometryOnSphere.distance(
	polygon,
	feature_reconstructed_geometry.get_reconstrued_geometry(),
	geometry1_is_solid=True,
	geometry2_is_solid=True)

• A minimum distance of 0 means that the current reconstructed geometry touches or overlaps the target area.

if min_distance_to_feature == 0:
	overlapping_features.append(feature)
	break

• Write overlapping plates to file.

overlapping_feature_collection = pygplates.FeatureCollection(overlapping_features)
overlapping_feature_filename = "features_overlapping_{0}Ma.gpml".format(reconstruction_time)
overlapping_feature_collection.write(overlapping_features_filename)