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internship/swash/processing/post.py

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2022-03-28 10:15:36 +02:00
import argparse
import configparser
import logging
import pathlib
import matplotlib.pyplot as plt
import numpy as np
import scipy.fft as fft
import scipy.signal as sgl
from .read_swash import *
parser = argparse.ArgumentParser(description="Post-process swash output")
parser.add_argument("-v", "--verbose", action="count", default=0)
args = parser.parse_args()
logging.basicConfig(level=max((10, 20 - 10 * args.verbose)))
log = logging.getLogger("post")
log.info("Starting post-processing")
config = configparser.ConfigParser()
config.read("config.ini")
inp = pathlib.Path(config.get("post", "inp"))
root = pathlib.Path(config.get("swash", "out"))
log.info(f"Reading data from '{inp}'")
x = np.load(inp.joinpath("xp.npy"))
t = np.load(inp.joinpath("tsec.npy"))
botl = np.load(inp.joinpath("botl.npy"))
watl = np.load(inp.joinpath("watl.npy"))
vel = np.load(inp.joinpath("vel.npy"))
# Cospectral calculations
x0 = config.getint("post", "x0")
arg_x0 = np.abs(x - x0).argmin()
t0 = config.getfloat("post", "t0")
arg_t0 = np.abs(t - t0).argmin()
dt = config.getfloat("post", "dt")
f = 1 / dt
nperseg = config.getint("post", "nperseg", fallback=None)
log.info(f"Computing reflection coefficient at x={x0}")
eta = watl[t > t0, arg_x0]
u = vel[t > t0, 0, arg_x0]
phi_eta = sgl.welch(eta, f, nperseg=nperseg)
phi_u = sgl.welch(u, f, nperseg=nperseg)
phi_eta_u = sgl.csd(eta, u, f, nperseg=nperseg)
H = np.sqrt(np.abs(phi_eta[1]))
U = np.sqrt(np.abs(phi_u[1]))
G = H / U
th_eta_u = np.angle(phi_eta_u[1])
# R1 = np.sqrt(
# (np.abs(phi_eta[1]) + np.abs(phi_u[1]) - 2 * np.abs(phi_eta_u[1]))
# / (np.abs(phi_eta[1]) + np.abs(phi_u[1]) + 2 * np.abs(phi_eta_u[1]))
# )
R = np.sqrt(
(1 + G**2 - 2 * G * np.cos(th_eta_u))
/ (1 + G**2 + 2 * G * np.cos(th_eta_u))
)
if config.has_option("post", "compare"):
inp_comp = pathlib.Path(config.get("post", "compare"))
x_ = np.load(inp_comp.joinpath("xp.npy"))
t_ = np.load(inp_comp.joinpath("tsec.npy"))
botl_ = np.load(inp_comp.joinpath("botl.npy"))
watl_ = np.load(inp_comp.joinpath("watl.npy"))
vel_ = np.load(inp_comp.joinpath("vel.npy"))
arg_x0_ = np.abs(x_ - x0).argmin()
arg_t0_ = np.abs(t_ - t0).argmin()
eta_ = watl_[t_ > t0, arg_x0_]
u_ = vel_[t_ > t0, 0, arg_x0_]
phi_eta_ = sgl.welch(eta_, f, nperseg=nperseg)
phi_u_ = sgl.welch(u_, f, nperseg=nperseg)
phi_eta_u_ = sgl.csd(eta_, u_, f, nperseg=nperseg)
H_ = np.sqrt(np.abs(phi_eta_[1]))
U_ = np.sqrt(np.abs(phi_u_[1]))
G_ = H_ / U_
th_eta_u_ = np.angle(phi_eta_u_[1])
R_ = np.sqrt(
(1 + G_**2 - 2 * G_ * np.cos(th_eta_u_))
/ (1 + G_**2 + 2 * G_ * np.cos(th_eta_u_))
)
# Plotting
log.info("Plotting results")
fig, (ax_watl, ax_vel) = plt.subplots(2)
ax_watl.plot(t, watl[:, arg_x0], lw=1, label="watl")
ax_watl.set(xlabel="t (s)", ylabel="z (m)")
ax_watl.autoscale(axis="x", tight=True)
ax_watl.grid()
ax_watl.axvline(t0, c="k", alpha=0.2)
ax_vel.plot(t, vel[:, 0, arg_x0], lw=1, label="vel")
ax_vel.set(xlabel="t (s)", ylabel="U (m/s)")
ax_vel.autoscale(axis="x", tight=True)
ax_vel.grid()
ax_vel.axvline(t0, c="k", alpha=0.2)
fig.tight_layout()
fig_r, ax_r = plt.subplots()
ax_fft = ax_r.twinx()
ax_fft.plot(
*sgl.welch(eta, 1 / dt, nperseg=nperseg),
lw=1,
c="k",
alpha=0.2,
label="PSD ($\\eta$, cas 1)",
)
ax_r.plot(phi_eta[0], R, marker="+", label="R (cas 1)")
if config.has_option("post", "compare"):
ax_fft.plot(
*sgl.welch(eta_, 1 / dt, nperseg=nperseg),
lw=1,
c="k",
alpha=0.2,
label="PSD ($\\eta$, cas 2)",
)
ax_r.plot(phi_eta[0], R_, marker="+", label="R (cas 2)")
ax_r.set(xlim=(0, 0.3), ylim=(0, 1), xlabel="f (Hz)", ylabel="R")
ax_fft.set(ylim=0, ylabel="PSD (m²/Hz)")
ax_r.grid()
ax_r.legend(loc="upper left")
ax_fft.legend(loc="upper right")
fig_r.tight_layout()
fig_x, ax_x = plt.subplots(figsize=(10, 1))
ax_x.plot(x, -botl, color="k")
ax_x.plot(
x,
np.maximum(watl[arg_t0, :], -botl),
)
if config.has_option("post", "compare"):
ax_x.plot(x, -botl_, color="k", ls="-.")
ax_x.plot(
x,
np.maximum(watl_[arg_t0, :], -botl_),
ls="-.",
)
ax_x.axvline(x0, c="k", alpha=0.2)
ax_x.set(xlabel="x (m)", ylabel="z (m)")
ax_x.autoscale(axis="x", tight=True)
ax_x.set(aspect="equal")
fig_x.tight_layout()
out = pathlib.Path(config.get("post", "out")).joinpath(f"t{t0}x{x0}")
log.info(f"Saving plots in '{out}'")
out.mkdir(parents=True, exist_ok=True)
fig.savefig(out.joinpath("t.png"))
fig_r.savefig(out.joinpath("R.png"))
fig_x.savefig(out.joinpath("x.png"))
plt.show(block=True)
log.info("Finished post-processing")