[转载] [转载] python反三角函数arctan_Python numpy.arctan() 使用实例

祁鸿哲

2023-12-01

参考链接： Python中的numpy.arcsin

The following are code examples for showing how to use . They are extracted from open source Python projects. You can vote up the examples you like or vote down the exmaples you don’t like. You can also save this page to your account.

Example 1

def get_polar_t(self):

mag = self.get_magnitude()

sizeimg = np.real(self.imgfft).shape

pol = np.zeros(sizeimg)

for x in range(sizeimg[0]):

for y in range(sizeimg[1]):

my = y - sizeimg[1] / 2

mx = x - sizeimg[0] / 2

if mx != 0:

phi = np.arctan(my / float(mx))

else:

phi = 0

r = np.sqrt(mx**2 + my **2)

ix = map_range(phi, -np.pi, np.pi, sizeimg[0], 0)

iy = map_range(r, 0, sizeimg[0], 0, sizeimg[1])

if ix >= 0 and ix < sizeimg[0] and iy >= 0 and iy < sizeimg[1]:

pol[x][y] = mag.data[int(ix)][int(iy)]

pol = MyImage(pol)

pol.limit(1)

return pol

Example 2

def calc_IndCurrent_cos_range(self,f,t):

"""Induced current over a range of times"""

Bpx = self.Bpx

Bpz = self.Bpz

a2 = self.a2

azm = np.pi*self.azm/180.

R = self.R

L = self.L

w = 2*np.pi*f

Ax = np.pi*a2**2*np.sin(azm)

Az = np.pi*a2**2*np.cos(azm)

Phi = (Ax*Bpx + Az*Bpz)

phi = np.arctan(R/(w*L))-np.pi # This is the phase and not phase lag

Is = -(w*Phi/(R*np.sin(phi) + w*L*np.cos(phi)))*np.cos(w*t + phi)

Ire = -(w*Phi/(R*np.sin(phi) + w*L*np.cos(phi)))*np.cos(w*t)*np.cos(phi)

Iim = (w*Phi/(R*np.sin(phi) + w*L*np.cos(phi)))*np.sin(w*t)*np.sin(phi)

return Ire,Iim,Is,phi

Example 3

def test_branch_cuts_complex64(self):

# check branch cuts and continuity on them

yield _check_branch_cut, np.log, -0.5, 1j, 1, -1, True, np.complex64

yield _check_branch_cut, np.log2, -0.5, 1j, 1, -1, True, np.complex64

yield _check_branch_cut, np.log10, -0.5, 1j, 1, -1, True, np.complex64

yield _check_branch_cut, np.log1p, -1.5, 1j, 1, -1, True, np.complex64

yield _check_branch_cut, np.sqrt, -0.5, 1j, 1, -1, True, np.complex64

yield _check_branch_cut, np.arcsin, [ -2, 2], [1j, 1j], 1, -1, True, np.complex64

yield _check_branch_cut, np.arccos, [ -2, 2], [1j, 1j], 1, -1, True, np.complex64

yield _check_branch_cut, np.arctan, [0-2j, 2j], [1, 1], -1, 1, True, np.complex64

yield _check_branch_cut, np.arcsinh, [0-2j, 2j], [1, 1], -1, 1, True, np.complex64

yield _check_branch_cut, np.arccosh, [ -1, 0.5], [1j, 1j], 1, -1, True, np.complex64

yield _check_branch_cut, np.arctanh, [ -2, 2], [1j, 1j], 1, -1, True, np.complex64

# check against bogus branch cuts: assert continuity between quadrants

yield _check_branch_cut, np.arcsin, [0-2j, 2j], [ 1, 1], 1, 1, False, np.complex64

yield _check_branch_cut, np.arccos, [0-2j, 2j], [ 1, 1], 1, 1, False, np.complex64

yield _check_branch_cut, np.arctan, [ -2, 2], [1j, 1j], 1, 1, False, np.complex64

yield _check_branch_cut, np.arcsinh, [ -2, 2, 0], [1j, 1j, 1], 1, 1, False, np.complex64

yield _check_branch_cut, np.arccosh, [0-2j, 2j, 2], [1, 1, 1j], 1, 1, False, np.complex64

yield _check_branch_cut, np.arctanh, [0-2j, 2j, 0], [1, 1, 1j], 1, 1, False, np.complex64

Example 4

def test_against_cmath(self):

import cmath

points = [-1-1j, -1+1j, +1-1j, +1+1j]

name_map = {'arcsin': 'asin', 'arccos': 'acos', 'arctan': 'atan',

'arcsinh': 'asinh', 'arccosh': 'acosh', 'arctanh': 'atanh'}

atol = 4*np.finfo(np.complex).eps

for func in self.funcs:

fname = func.__name__.split('.')[-1]

cname = name_map.get(fname, fname)

try:

cfunc = getattr(cmath, cname)

except AttributeError:

continue

for p in points:

a = complex(func(np.complex_(p)))

b = cfunc(p)

assert_(abs(a - b) < atol, "%s %s: %s; cmath: %s" % (fname, p, a, b))

Example 5

def effect(self, point):

res = []

# print(self.centers)

for center in self.centers:

center_x, center_y = center

src_x, src_y = point.pos

# Check angle

angle = np.arctan((center_x - src_x) / (center_y - src_y))

if np.abs(angle) > self.angle / 2:

continue

angle = np.deg2rad(90) + angle

u_len = np.sqrt((center_x - src_x) ** 2 + (center_y - src_y) ** 2)

reverse_v = (self.r_index - 1) / self.radius - self.r_index / u_len

v_len = 1 / reverse_v

if v_len > 0:

p_type = 'real'

else:

p_type = 'fake'

target = line_end(point.pos, angle, u_len + v_len)

p = Point(target, p_type, 1)

# point.passed.append(self)

res.append(p)

return tuple(res)

Example 6

def _radian_direction(dy,dx):

'''

function:

- based on given dy and dx it calculates direction in radian.

- used in feature_eng_pt3

input:

dy = change in y

dx = change in x

output:

returns radian value (0 to 6.28)

'''

if dy < 0.0 and dx > 0.0:

return (2*np.pi + np.arctan(dy/dx))

elif dy >=0.0 and dx > 0.0:

return (np.arctan(dy/dx))

else:

return np.pi + np.arctan(dy/dx)

Example 7

def flow(self, Kc, Ks, Kz, Ka, numexpr):

zeros = np.zeros

where = np.where

min = np.minimum

max = np.maximum

abs = np.absolute

arctan = np.arctan

sin = np.sin

center = (slice( 1, -1,None),slice( 1, -1,None))

rock = self.center

ds = self.scour[center]

rcc = rock[center]

rock[center] = rcc - ds * Kz

# there isn't really a bottom to the rock but negative values look ugly

rock[center] = where(rcc<0,0,rcc)

Example 8

def fixOffset(self, offset, img):

size = img.shape

finalImg = np.ndarray(size)

indices = np.indices((self.videoSize[0],self.videoSize[1])).swapaxes(0,2).swapaxes(0,1)

indices = np.around(indices, decimals=1)

indices.shape = (self.videoSize[1] * self.videoSize[0], 2)

phi = 2 * np.arctan(np.exp(indices[:, 1] / self.videoSize[1])) - 1/2 * np.pi - offset[0]

lamb = indices[:, 0] - offset[1]

x = lamb

y = np.log(np.tan(np.pi / 4 + 1/2 * phi)) * self.videoSize[1]

finalIdx = np.ndarray((self.videoSize[1] * self.videoSize[0], 2))

finalIdx = np.around(finalIdx, decimals=1).astype(int)

finalIdx[:, 1] = y % self.videoSize[1]

finalIdx[:, 0] = x % self.videoSize[0]

finalImg[indices[:,1], indices[:,0]] = img[finalIdx[:,1], finalIdx[:,0]]

return finalImg

Example 9

def _dip_slip_y(self, y1, y2, ang_dip, q):

"""

Based on Okada's paper (1985)

y = down-dip direction

"""

sn = numpy.sin(ang_dip)

cs = numpy.cos(ang_dip)

d_bar = y2*sn - q*cs;

r = numpy.sqrt(y1**2 + y2**2 + q**2)

xx = numpy.sqrt(y1**2 + q**2)

y_bar = y2*cs + q*sn

a5 = 4.*poisson/cs*numpy.arctan((y2*(xx+q*cs)+xx*(r+xx)*sn)/y1/(r+xx)/cs)

a1 = 2.0*poisson*(-y1/(cs*(r+d_bar))) - sn/cs * a5

f = -(y_bar*q/r/(r+y1) + cs*numpy.arctan(y1*y2/q/r) - a1*sn*cs)/(2.0*3.14159)

return f

Example 10

def _dip_slip_x(self, y1, y2, ang_dip, q):

"""

Based on Okada's paper (1985)

Added by Xiaoming Wang

"""

sn = numpy.sin(ang_dip)

cs = numpy.cos(ang_dip)

d_bar = y2*sn - q*cs;

r = numpy.sqrt(y1**2 + y2**2 + q**2)

xx = numpy.sqrt(y1**2 + q**2)

#a5 = 4.*poisson/cs*numpy.arctan((y2*(xx+q*cs)+xx*(r+xx)*sn)/y1/(r+xx)/cs)

a4 = 2.0*poisson/cs*(numpy.log(r+d_bar) - sn*numpy.log(r+y2))

ytilde = y2*cs + q*sn

a3 = 2.0*poisson*(ytilde/(cs*(r+d_bar)) - numpy.log(r+y2)) + a4*sn/cs

f = -(q/r - a3*sn*cs)/(2.0*3.14159)

return f

Example 11

def _dip_slip_x(self, y1, y2, ang_dip, q):

"""

Based on Okada's paper (1985)

Added by Xiaoming Wang

"""

sn = numpy.sin(ang_dip)

cs = numpy.cos(ang_dip)

d_bar = y2*sn - q*cs;

r = numpy.sqrt(y1**2 + y2**2 + q**2)

xx = numpy.sqrt(y1**2 + q**2)

#a5 = 4.*poisson/cs*numpy.arctan((y2*(xx+q*cs)+xx*(r+xx)*sn)/y1/(r+xx)/cs)

a4 = 2.0*poisson/cs*(numpy.log(r+d_bar) - sn*numpy.log(r+y2))

ytilde = y2*cs + q*sn

a3 = 2.0*poisson*(ytilde/(cs*(r+d_bar)) - numpy.log(r+y2)) + a4*sn/cs

f = -(q/r - a3*sn*cs)/(2.0*3.14159)

return f

Example 12

def get_q_per_pixel(self):

'''Gets the delta-q associated with a single pixel. This is computed in

the small-angle limit, so it should only be considered approximate.

For instance, wide-angle detectors will have different delta-q across

the detector face.'''

if self.q_per_pixel is not None:

return self.q_per_pixel

c = (self.pixel_size_um/1e6)/self.distance_m

twotheta = np.arctan(c) # radians

self.q_per_pixel = 2.0*self.get_k()*np.sin(twotheta/2.0)

return self.q_per_pixel

# Maps

########################################

Example 13

def reset_model(self):

self._min_strike_dist = np.inf

self._striked = False

self._strike_pos = None

qpos = self.init_qpos

self.ball = np.array([0.5, -0.175])

while True:

self.goal = np.concatenate([

self.np_random.uniform(low=0.15, high=0.7, size=1),

self.np_random.uniform(low=0.1, high=1.0, size=1)])

if np.linalg.norm(self.ball - self.goal) > 0.17:

break

qpos[-9:-7] = [self.ball[1], self.ball[0]]

qpos[-7:-5] = self.goal

diff = self.ball - self.goal

angle = -np.arctan(diff[0] / (diff[1] + 1e-8))

qpos[-1] = angle / 3.14

qvel = self.init_qvel + self.np_random.uniform(low=-.1, high=.1,

size=self.model.nv)

qvel[7:] = 0

self.set_state(qpos, qvel)

return self._get_obs()

Example 14