"""Import or export Nemoh.cal files for backward compatibility with Nemoh 2."""
# Copyright (C) 2017-2019 Matthieu Ancellin
# See LICENSE file at <https://github.com/mancellin/capytaine>
import os
import logging
import numpy as np
from capytaine.bem.solver import BEMSolver
from capytaine.io.xarray import assemble_dataset
from capytaine.meshes.io import load_mesh
from capytaine.bodies.bodies import FloatingBody
from capytaine.bem.problems_and_results import DiffractionProblem, RadiationProblem
LOG = logging.getLogger(__name__)
[docs]
def import_cal_file(filepath):
"""Read a Nemoh.cal file and return a list of problems."""
with open(filepath, 'r') as cal_file:
cal_file.readline() # Unused line.
rho = float(cal_file.readline().split()[0])
g = float(cal_file.readline().split()[0])
water_depth = float(cal_file.readline().split()[0])
if water_depth == 0.0:
water_depth = np.inf
xeff, yeff = (float(x) for x in cal_file.readline().split()[0:2])
bodies = []
cal_file.readline() # Unused line.
nb_bodies = int(cal_file.readline().split()[0])
for _ in range(nb_bodies):
cal_file.readline() # Unused line.
mesh_file = cal_file.readline().split()[0].strip()
mesh_file = os.path.join(os.path.dirname(filepath), mesh_file) # mesh path are relative to Nemoh.cal
cal_file.readline() # Number of points, number of panels (unused)
if os.path.splitext(mesh_file)[1] == '.py':
from importlib.util import spec_from_file_location, module_from_spec
spec = spec_from_file_location("body_initialization_module", mesh_file)
body_initialization = module_from_spec(spec)
spec.loader.exec_module(body_initialization)
body = body_initialization.body
else:
body = FloatingBody(mesh=load_mesh(mesh_file, file_format='nemoh'))
nb_dofs = int(cal_file.readline().split()[0])
for i_dof in range(nb_dofs):
dof_data = cal_file.readline().split()
if int(dof_data[0]) == 1:
direction = np.array([float(x) for x in dof_data[1:4]])
body.add_translation_dof(direction=direction)
elif int(dof_data[0]) == 2:
direction = np.array([float(x) for x in dof_data[1:4]])
center_of_mass = np.array([float(x) for x in dof_data[4:7]])
body.add_rotation_dof(direction=direction, rotation_center=center_of_mass)
nb_forces = int(cal_file.readline().split()[0])
for i_force in range(nb_forces):
force_data = cal_file.readline().split()
if int(force_data[0]) == 1:
direction = np.array([float(x) for x in force_data[1:4]])
elif int(force_data[0]) == 2:
direction = np.array([float(x) for x in force_data[1:4]])
center_of_mass = np.array([float(x) for x in force_data[4:7]])
# TODO: use the generalized forces.
nb_additional_lines = int(cal_file.readline().split()[0])
for _ in range(nb_additional_lines):
cal_file.readline() # The additional lines are just ignored.
bodies.append(body)
if nb_bodies > 1:
bodies = FloatingBody.join_bodies(*bodies)
else:
bodies = bodies[0]
cal_file.readline() # Unused line.
frequency_data_string_without_comment = cal_file.readline().split('!')[0]
frequency_data = frequency_data_string_without_comment.split()
if len(frequency_data) == 3: # Nemoh v2 format
omega_range = np.linspace(float(frequency_data[1]), float(frequency_data[2]), int(frequency_data[0]))
else:
type_of_frequency_data = int(frequency_data[0])
if type_of_frequency_data == 1: # angular frequency
omega_range = np.linspace(float(frequency_data[2]), float(frequency_data[3]), int(frequency_data[1]))
elif type_of_frequency_data == 2: # frequency
omega_range = 2*np.pi*np.linspace(float(frequency_data[2]), float(frequency_data[3]), int(frequency_data[1]))
elif type_of_frequency_data == 3: # period
omega_range = 2*np.pi/np.linspace(float(frequency_data[2]), float(frequency_data[3]), int(frequency_data[1]))
else:
raise ValueError(f"Cannot parse the frequency data \"{frequency_data_string_without_comment}\" in {filepath}.")
direction_data = cal_file.readline().split()
direction_range = np.linspace(float(direction_data[1]), float(direction_data[2]), int(direction_data[0]))
direction_range = np.pi/180*direction_range # conversion from degrees to radians.
# The options below are not implemented yet.
cal_file.readline() # Unused line.
irf_data = cal_file.readline()
show_pressure = cal_file.readline().split()[0] == "1"
kochin_data = cal_file.readline().split()
kochin_range = np.linspace(float(kochin_data[1]), float(kochin_data[2]), int(kochin_data[0]))
free_surface_data = cal_file.readline().split()
# Generate Capytaine's problem objects
env_args = dict(body=bodies, rho=rho, water_depth=water_depth, g=g)
problems = []
for omega in omega_range:
for direction in direction_range:
problems.append(DiffractionProblem(wave_direction=direction, omega=omega, **env_args))
for dof in bodies.dofs:
problems.append(RadiationProblem(radiating_dof=dof, omega=omega, **env_args))
return problems
[docs]
def write_dataset_as_tecplot_files(results_directory, data):
"""Write some of the data from a xarray dataset into legacy tecplot file outputs."""
if 'added_mass' in data:
with open(os.path.join(results_directory, 'RadiationCoefficients.tec'), 'w') as fi:
for i in range(len(data['radiating_dof'])+1):
fi.write(f'...\n')
for dof in data.radiating_dof:
fi.write(f'{dof.values}\n')
for o in data.omega:
fi.write(f' {o.values:e} ')
for dof2 in data.influenced_dof:
fi.write(f"{data['added_mass'].sel(omega=o, radiating_dof=dof, influenced_dof=dof2).values:e}")
fi.write(' ')
fi.write(f"{data['radiation_damping'].sel(omega=o, radiating_dof=dof, influenced_dof=dof2).values:e}")
fi.write(' ')
fi.write('\n')
if 'diffraction_force' in data:
data['excitation_force'] = data['Froude_Krylov_force'] + data['diffraction_force']
with open(os.path.join(results_directory, 'ExcitationForce.tec'), 'w') as fi:
for i in range(len(data.influenced_dof)+1):
fi.write(f'...\n')
for wave_direction in data.wave_direction.values:
fi.write(f'angle={wave_direction}\n')
for o in data.omega.values:
fi.write(f' {o:e} ')
for dof in data.influenced_dof:
val = data['excitation_force'].sel(omega=o, wave_direction=wave_direction, influenced_dof=dof).values
fi.write(f'{np.abs(val):e}')
fi.write(' ')
fi.write(f'{np.angle(val):e}')
fi.write(' ')
fi.write('\n')
def _hydrostatics_writer(hydrostatics_file_path, kh_file_path, body):
"""Write the Hydrostatics.dat and KH.dat files"""
with open(hydrostatics_file_path, 'w') as hf:
for j in range(3):
line = f'XF = {body.center_of_buoyancy[j]:7.4f} - XG = {body.center_of_mass[j]:7.4f} \n'
hf.write(line)
line = f'Displacement = {body.volume:1.6E}'
hf.write(line)
hf.close()
np.savetxt(kh_file_path, body.hydrostatic_stiffness.values, fmt='%1.6E')
[docs]
def export_hydrostatics(hydrostatics_directory, bodies):
"""Export rigid body hydrostatics in Nemoh's format (KH.dat and Hydrostatics.dat).
Parameters
----------
hydrostatics_directory: string
Path to the directory in which the data will be written (two files per body)
bodies: FloatingBody or list of FloatingBody
The body or the list of bodies. Each body is assumed to be a single
rigid body with 6 dofs. Each FloatingBody object is expected to have an
`inertia_matrix` and a `hydrostatic_stiffness` parameter.
Return
------
None
"""
if os.path.isdir(hydrostatics_directory):
LOG.warning(f"""Exporting problem in already existing directory: {hydrostatics_directory}
You might be overwriting existing files!""")
else:
os.makedirs(hydrostatics_directory)
if isinstance(bodies, FloatingBody):
bodies = [bodies]
hydrostatics_file_name = "Hydrostatics.dat"
kh_file_name = "KH.dat"
body_count = len(bodies)
if body_count == 1:
body = bodies[0]
hydrostatics_file_path = os.path.join(hydrostatics_directory, hydrostatics_file_name)
kh_file_path = os.path.join(hydrostatics_directory, kh_file_name)
_hydrostatics_writer(hydrostatics_file_path, kh_file_path, body)
else:
for (i, body) in enumerate(bodies):
hydrostatics_file_path = os.path.join(hydrostatics_directory, f"Hydrostatics_{i}.dat")
kh_file_path = os.path.join(hydrostatics_directory, f"KH_{i}.dat")
_hydrostatics_writer(hydrostatics_file_path, kh_file_path, body)
[docs]
def run_cal_file(paramfile):
problems = import_cal_file(paramfile)
solver = BEMSolver()
results = solver.solve_all(problems)
data = assemble_dataset(results)
results_directory = os.path.join(os.path.dirname(paramfile), 'results')
try:
os.mkdir(results_directory)
except FileExistsError:
LOG.warning(f"The output directory ({results_directory}) already exists. You might be overwriting existing data.")
LOG.info("Write results in legacy tecplot format.")
write_dataset_as_tecplot_files(results_directory, data)