def corners(self, gmt_format=False):
"""
Retrieve corners of simulation domain.
gmt_format: if True, also returns corners in GMT string format
"""
# compared with model_params format:
# c1 = x0 y0
# c2 = xmax y0
# c3 = xmax ymax
# c4 = x0 ymax
# cannot just use self.ll_map as xmax, ymax for simulation domain
# may have been decimated. sim nx 1400 (xmax 1399) with dxts 5 = 1395
gp_cnrs = np.array(
[
[0, 0],
[self.nx_sim - 1, 0],
[self.nx_sim - 1, self.ny_sim - 1],
[0, self.ny_sim - 1],
]
)
amat = geo.gen_mat(self.mrot, self.mlon, self.mlat)[0]
ll_cnrs = geo.xy2ll(geo.gp2xy(gp_cnrs, self.nx_sim, self.ny_sim, self.hh), amat)
if np.min(ll_cnrs[:, 0]) < -90 and np.max(ll_cnrs[:, 0]) > 90:
# assume crossing over 180 -> -180, extend past 180
ll_cnrs[ll_cnrs[:, 0] < 0, 0] += 360
if not gmt_format:
return ll_cnrs.tolist()
gmt_cnrs = "\n".join([" ".join(map(str, cnr)) for cnr in ll_cnrs])
return ll_cnrs.tolist(), gmt_cnrs
def __init__(self, xyts_path, meta_only=False):
"""
Load metadata and optionally prepare gridpoint datum locations.
xyts_path: path to the xyts.e3d file
meta_only: don't prepare gridpoint datum locations (slower)
can't use timeslice (lon, lat, value) capability
"""
xytf = open(xyts_path, "rb")
# determine endianness, an x-y timeslice has 1 z value
nz = np.fromfile(xytf, dtype=">i4", count=7)[-1]
if nz == 0x00000001:
endian = ">"
elif nz == 0x01000000:
endian = "<"
else:
xytf.close()
raise ValueError("File is not an XY timeslice file: %s" % (xyts_path))
xytf.seek(0)
# read header
self.x0, self.y0, self.z0, self.t0, self.nx, self.ny, self.nz, self.nt = np.fromfile(
xytf, dtype="%si4" % (endian), count=8
)
self.dx, self.dy, self.hh, dt, self.mrot, self.mlat, self.mlon = np.fromfile(
xytf, dtype="%sf4" % (endian), count=7
)
xytf.close()
# dt is sensitive to float error eg 0.2 stores as 0.199999 (dangerous)
self.dt = np.around(dt, decimals=4)
# determine original sim parameters
self.dxts = int(round(self.dx / self.hh))
self.dyts = int(round(self.dy / self.hh))
self.nx_sim = self.nx * self.dxts
self.ny_sim = self.ny * self.dyts
# orientation of components
self.dip = 0
self.comps = {
"X": radians(90 + self.mrot),
"Y": radians(self.mrot),
"Z": radians(90 - self.dip),
}
# rotation of components so Y is true north
self.cosR = cos(self.comps["X"])
self.sinR = sin(self.comps["X"])
# simulation plane always flat, dip = 0
self.cosP = 0 # cos(self.comps['Z'])
self.sinP = 1 # sin(self.comps['Z'])
# xy dual component rotation matrix
# must also flip vertical axis
theta = radians(self.mrot)
self.rot_matrix = np.array(
[[cos(theta), -sin(theta), 0], [-sin(theta), -cos(theta), 0], [0, 0, -1]]
)
# save speed when only loaded to read metadata section
if meta_only:
return
# memory map for data section
self.data = np.memmap(
xyts_path,
dtype="%sf4" % (endian),
mode="r",
offset=60,
shape=(self.nt, len(self.comps), self.ny, self.nx),
)
# create longitude, latitude map for data
grid_points = (
np.mgrid[0 : self.nx_sim : self.dxts, 0 : self.ny_sim : self.dyts]
.reshape(2, -1, order="F")
.T
)
amat = geo.gen_mat(self.mrot, self.mlon, self.mlat)[0]
ll_map = geo.xy2ll(
geo.gp2xy(grid_points, self.nx_sim, self.ny_sim, self.hh), amat
).reshape(self.ny, self.nx, 2)
if np.min(ll_map[:, :, 0]) < -90 and np.max(ll_map[:, :, 0]) > 90:
# assume crossing over 180 -> -180, extend past 180
ll_map[ll_map[:, :, 0] < 0, 0] += 360
self.ll_map = ll_map
def test_gp2xy(gp, nx, ny, hh, expected):
assert np.allclose(geo.gp2xy(gp, nx, ny, hh), expected, atol=1e-5)