Python math._sin函数代码示例

def theta_ratio_bounds(theta, theta_tol, ratio, ratio_tol):
    """ Prepare last four arguments to blobs2features.
    
        Check bounds on theta so that zero is not crossed and on ration
        so that one is not crossed, either of which would indicate a feature
        flipped around its primary axis.
    """
    # adjust tolerances down with small angles
    ratio_tol *= _sin(abs(theta))
    theta_tol *= _sin(abs(theta))
    
    if theta > 0.0:
        min_theta, max_theta = max(0.0, theta - theta_tol), theta + theta_tol
    elif theta < 0.0:
        min_theta, max_theta = theta - theta_tol, min(0.0, theta + theta_tol)
    else:
        # zero? weird.
        min_theta, max_theta = 0.0, 0.0
    
    if ratio > 1.0:
        min_ratio, max_ratio = max(1.0, ratio - ratio_tol), ratio + ratio_tol
    elif ratio < 1.0:
        min_ratio, max_ratio = ratio - ratio_tol, min(1.0, ratio + ratio_tol)
    else:
        # one? weird.
        min_ratio, max_ratio = 1.0, 1.0
    
    return min_theta, max_theta, min_ratio, max_ratio

def _measure(p1, p2, p3):
    """ Return hypotenuse, ratio and theta for a trio of ordered points.
    """
    ha, hb = _hypot(p3.x - p1.x, p3.y - p1.y), _hypot(p2.x - p1.x, p2.y - p1.y)
    va, vb = Vector(p1, p2), Vector(p1, p3)
    
    theta = _atan2(va.y, va.x)
    
    x = vb.x * _cos(-theta) - vb.y * _sin(-theta)
    y = vb.x * _sin(-theta) + vb.y * _cos(-theta)
    
    ratio = ha / hb
    theta = _atan2(y, x)
    
    return hb, ratio, theta

 def rotozoom(self, surface, angle, size):
     """
     Return Surface rotated and resized by the given angle and size.
     """
     if not angle:
         width = int(surface.getWidth()*size)
         height = int(surface.getHeight()*size)
         return self.scale(surface, (width, height))
     theta = angle*self.deg_rad
     width_i = int(surface.getWidth()*size)
     height_i = int(surface.getHeight()*size)
     cos_theta = _fabs( _cos(theta) )
     sin_theta = _fabs( _sin(theta) )
     width_f = int( _ceil((width_i*cos_theta)+(height_i*sin_theta)) )
     if width_f % 2:
         width_f += 1
     height_f = int( _ceil((width_i*sin_theta)+(height_i*cos_theta)) )
     if height_f % 2:
         height_f += 1
     surf = Surface((width_f,height_f), BufferedImage.TYPE_INT_ARGB)
     at = AffineTransform()
     at.translate(width_f/2, height_f/2)
     at.rotate(-theta)
     g2d = surf.createGraphics()
     ot = g2d.getTransform()
     g2d.setTransform(at)
     g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR)
     g2d.drawImage(surface, -width_i//2, -height_i//2, width_i, height_i, None)
     g2d.setTransform(ot)
     g2d.dispose()
     return surf

 def rotate(self, surface, angle):
     """
     Return Surface rotated by the given angle.
     """
     if not angle:
         return surface.copy()
     theta = angle*self.deg_rad
     width_i = surface.getWidth()
     height_i = surface.getHeight()
     cos_theta = _fabs( _cos(theta) )
     sin_theta = _fabs( _sin(theta) )
     width_f = int( (width_i*cos_theta)+(height_i*sin_theta) )
     height_f = int( (width_i*sin_theta)+(height_i*cos_theta) )
     surf = Surface((width_f,height_f), BufferedImage.TYPE_INT_ARGB)
     at = AffineTransform()
     at.translate(width_f/2, height_f/2)
     at.rotate(-theta)
     g2d = surf.createGraphics()
     ot = g2d.getTransform()
     g2d.setTransform(at)
     g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR)
     g2d.drawImage(surface, -width_i//2, -height_i//2, None)
     g2d.setTransform(ot)
     g2d.dispose()
     return surf

def rotate(m,angle,v):
    """
    :param m: should be colunm major
    :param angle: in degree
    :param v:
    :return: in row major
    """
    c = _cos(angle)
    s = _sin(angle)

    axis = normalize(v)
    temp =(1. - c) * axis

    Rotate = numpy.zeros((4, 4), 'f')
    Rotate[0][0] = c + temp[0] * axis[0]
    Rotate[0][1] = 0 + temp[0] * axis[1] + s * axis[2]
    Rotate[0][2] = 0 + temp[0] * axis[2] - s * axis[1]

    Rotate[1][0] = 0 + temp[1] * axis[0] - s * axis[2]
    Rotate[1][1] = c + temp[1] * axis[1]
    Rotate[1][2] = 0 + temp[1] * axis[2] + s * axis[0]

    Rotate[2][0] = 0 + temp[2] * axis[0] + s * axis[1]
    Rotate[2][1] = 0 + temp[2] * axis[1] - s * axis[0]
    Rotate[2][2] = c + temp[2] * axis[2]

    Result = numpy.zeros((4, 4), 'f')
    Result[0] = m[0] * Rotate[0][0] + m[1] * Rotate[0][1] + m[2] * Rotate[0][2]
    Result[1] = m[0] * Rotate[1][0] + m[1] * Rotate[1][1] + m[2] * Rotate[1][2]
    Result[2] = m[0] * Rotate[2][0] + m[1] * Rotate[2][1] + m[2] * Rotate[2][2]
    Result[3] = m[3]
    return Result.T

    def gauss(self, mu, sigma):
        # """Gaussian distribution.
        # mu is the mean, and sigma is the standard deviation.  This is
        # slightly faster than the normalvariate() function.
        # Not thread-safe without a lock around calls.
        # """

        # When x and y are two variables from [0, 1), uniformly
        # distributed, then
        #
        #    cos(2*pi*x)*sqrt(-2*log(1-y))
        #    sin(2*pi*x)*sqrt(-2*log(1-y))
        #
        # are two *independent* variables with normal distribution
        # (mu = 0, sigma = 1).
        # (Lambert Meertens)
        # (corrected version; bug discovered by Mike Miller, fixed by LM)

        # Multithreading note: When two threads call this function
        # simultaneously, it is possible that they will receive the
        # same return value.  The window is very small though.  To
        # avoid this, you have to use a lock around all calls.  (I
        # didn't want to slow this down in the serial case by using a
        # lock here.)

        __random = self.random
        z = self.gauss_next
        self.gauss_next = None
        if z is None:
            x2pi = __random() * TWOPI
            g2rad = _sqrt(-2.0 * _log(1.0 - __random()))
            z = _cos(x2pi) * g2rad
            self.gauss_next = _sin(x2pi) * g2rad

        return mu + z*sigma

 def rotozoom(self, surface, angle, size):
     """
     Return Surface rotated and resized by the given angle and size.
     """
     if not angle:
         width = int(surface.get_width()*size)
         height = int(surface.get_height()*size)
         return self.scale(surface, (width, height))
     theta = angle*self.deg_rad
     width_i = int(surface.get_width()*size)
     height_i = int(surface.get_height()*size)
     cos_theta = _fabs( _cos(theta) )
     sin_theta = _fabs( _sin(theta) )
     width_f = int( _ceil((width_i*cos_theta)+(height_i*sin_theta)) )
     if width_f % 2:
         width_f += 1
     height_f = int( _ceil((width_i*sin_theta)+(height_i*cos_theta)) )
     if height_f % 2:
         height_f += 1
     surf = Surface((width_f,height_f))
     surf.saveContext()
     surf.translate(width_f/2.0, height_f/2.0)
     surf.rotate(-theta)
     surf.drawImage(surface.canvas, 0, 0, surface.get_width(), surface.get_height(), -width_i/2, -height_i/2, width_i, height_i)
     surf.restoreContext()
     return surf

 def gauss(self, mu, sigma):
     random = self.random
     z = self.gauss_next
     self.gauss_next = None
     if z is None:
         x2pi = random() * TWOPI
         g2rad = _sqrt(-2.0 * _log(1.0 - random()))
         z = _cos(x2pi) * g2rad
         self.gauss_next = _sin(x2pi) * g2rad
     return mu + z * sigma

 def gauss(self, mu, sigma):
     """Gaussian distribution.
     
     mu is the mean, and sigma is the standard deviation.  This is
     slightly faster than the normalvariate() function.
     
     Not thread-safe without a lock around calls.
     
     """
     random = self.random
     z = self.gauss_next
     self.gauss_next = None
     if z is None:
         x2pi = random() * TWOPI
         g2rad = _sqrt(-2.0 * _log(1.0 - random()))
         z = _cos(x2pi) * g2rad
         self.gauss_next = _sin(x2pi) * g2rad
     return mu + z * sigma

 def rotate(self, surface, angle):
     """
     Return Surface rotated by the given angle.
     """
     if not angle:
         return surface.copy()
     theta = angle*self.deg_rad
     width_i = surface.get_width()
     height_i = surface.get_height()
     cos_theta = _fabs( _cos(theta) )
     sin_theta = _fabs( _sin(theta) )
     width_f = int( (width_i*cos_theta)+(height_i*sin_theta) )
     height_f = int( (width_i*sin_theta)+(height_i*cos_theta) )
     surf = Surface((width_f,height_f))
     surf.saveContext()
     surf.translate(width_f/2.0, height_f/2.0)
     surf.rotate(-theta)
     surf.drawImage(surface.canvas, -width_i/2, -height_i/2)
     surf.restoreContext()
     return surf

 
 dab = _sqrt((b.x - a.x) ** 2 + (b.y - a.y) ** 2)
 dbc = _sqrt((c.x - b.x) ** 2 + (c.y - b.y) ** 2)
 dac = _sqrt((c.x - a.x) ** 2 + (c.y - a.y) ** 2)
 
 ratios = {(0, 1, 2): dac/dab, (1, 0, 2): dbc/dab, (2, 1, 0): dac/dbc}
 
 tab = _atan2(b.y - a.y, b.x - a.x)
 tba = _atan2(a.y - b.y, a.x - b.x)
 tac = _atan2(c.y - a.y, c.x - a.x)
 tca = _atan2(a.y - c.y, a.x - c.x)
 tbc = _atan2(c.y - b.y, c.x - b.x)
 tcb = _atan2(b.y - c.y, b.x - c.x)
 
 thetas = {
     (0, 1, 2): _atan2((c.x - a.x) * _sin(-tab) + (c.y - a.y) * _cos(-tab),
                       (c.x - a.x) * _cos(-tab) - (c.y - a.y) * _sin(-tab)),
     
     (1, 0, 2): _atan2((c.x - b.x) * _sin(-tba) + (c.y - b.y) * _cos(-tba),
                       (c.x - b.x) * _cos(-tba) - (c.y - b.y) * _sin(-tba)),
     
     (0, 2, 1): _atan2((b.x - a.x) * _sin(-tac) + (b.y - a.y) * _cos(-tac),
                       (b.x - a.x) * _cos(-tac) - (b.y - a.y) * _sin(-tac)),
     
     (2, 0, 1): _atan2((b.x - c.x) * _sin(-tca) + (b.y - c.y) * _cos(-tca),
                       (b.x - c.x) * _cos(-tca) - (b.y - c.y) * _sin(-tca)),
     
     (1, 2, 0): _atan2((a.x - b.x) * _sin(-tbc) + (a.y - b.y) * _cos(-tbc),
                       (a.x - b.x) * _cos(-tbc) - (a.y - b.y) * _sin(-tbc)),
     
     (2, 1, 0): _atan2((a.x - c.x) * _sin(-tcb) + (a.y - c.y) * _cos(-tcb),

 def update(self,time=1):
     distance = self.s*time
     y = (_sin(self.d))*distance
     x = (_cos(self.d))*distance
     self.x += x
     self.y += y

def test_evalonarray_ctypes():
    a = frange('lambda x: x', 10)
    evalonarray('lambda x: _sin(x)', a)
    for i, j in enumerate(a):
        if _sin(i) != j:
            raise ValueError("Values should be equal")

def benchmark():
    """
    Run some benchmarks for clambdify and frange.

    NumPy and Psyco are used as reference if available.
    """
    from time import time
    from timeit import Timer

    def fbenchmark(f, var=[Symbol('x')]):
        """
        Do some benchmarks with f using clambdify, lambdify and psyco.
        """
        global cf, pf, psyf
        start = time()
        cf = clambdify(var, f)
        print('compile time (including sympy overhead): %f s' % (
            time() - start))
        pf = lambdify(var, f, 'math')
        psyf = None
        psyco = import_module('psyco')
        if psyco:
            psyf = lambdify(var, f, 'math')
            psyco.bind(psyf)
        code = '''for x in (i/1000. for i in range(1000)):
        f(%s)''' % ('x,'*len(var)).rstrip(',')
        t1 = Timer(code, 'from __main__ import cf as f')
        t2 = Timer(code, 'from __main__ import pf as f')
        if psyf:
            t3 = Timer(code, 'from __main__ import psyf as f')
        else:
            t3 = None
        print('for x = (0, 1, 2, ..., 999)/1000')
        print('20 times in 3 runs')
        print('compiled:      %.4f %.4f %.4f' % tuple(t1.repeat(3, 20)))
        print('Python lambda: %.4f %.4f %.4f' % tuple(t2.repeat(3, 20)))
        if t3:
            print('Psyco lambda:  %.4f %.4f %.4f' % tuple(t3.repeat(3, 20)))

    print('big function:')
    from sympy import _exp, _sin, _cos, pi
    x = Symbol('x')
##    f1 = diff(_exp(x)**2 - _sin(x)**pi, x) \
##        * x**12-2*x**3+2*_exp(x**2)-3*x**7+4*_exp(123+x-x**5+2*x**4) \
##        * ((x + pi)**5).expand()
    f1 = 2*_exp(x**2) + x**12*(-pi*_sin(x)**((-1) + pi)*_cos(x) + 2*_exp(2*x)) \
        + 4*(10*pi**3*x**2 + 10*pi**2*x**3 + 5*pi*x**4 + 5*x*pi**4 + pi**5
        + x**5)*_exp(123 + x + 2*x**4 - x**5) - 2*x**3 - 3*x**7
    fbenchmark(f1)
    print()
    print('simple function:')
    y = Symbol('y')
    f2 = sqrt(x*y) + x*5
    fbenchmark(f2, [x, y])
    times = 100000
    fstr = '_exp(_sin(_exp(-x**2)) + sqrt(pi)*_cos(x**5/(x**3-x**2+pi*x)))'
    print
    print('frange with f(x) =')
    print(fstr)
    print('for x=1, ..., %i' % times)
    print('in 3 runs including full compile time')
    t4 = Timer("frange('lambda x: %s', 0, %i)" % (fstr, times),
               'from __main__ import frange')

    numpy = import_module('numpy')

    print('frange:        %.4f %.4f %.4f' % tuple(t4.repeat(3, 1)))
    if numpy:
        t5 = Timer('x = arange(%i); result = %s' % (times, fstr),
                   'from numpy import arange, sqrt, exp, sin, cos, exp, pi')
        print('numpy:         %.4f %.4f %.4f' % tuple(t5.repeat(3, 1)))

def blobs2features(blobs, min_hypot=0, min_theta=-pi, max_theta=pi, min_ratio=0, max_ratio=1):
    """ Generate a stream of features conforming to limits.
    
        Yields 5-element tuples: indexes for three blobs followed by feature ratio, theta.
    """
    count = len(blobs)
    
    # one-dimensional arrays of simple positions
    xs = _array([blob.x for blob in blobs], dtype=float)
    ys = _array([blob.y for blob in blobs], dtype=float)
    
    #
    # two-dimensional arrays of component distances between each blob
    #   dx = b.x - a.x, dy = b.y - a.y
    #
    xs_ = repeat(reshape(xs, (1, count)), count, 0)
    ys_ = repeat(reshape(ys, (1, count)), count, 0)
    dxs, dys = transpose(xs_) - xs_, transpose(ys_) - ys_
    
    #
    # two-dimensional array of distances between each blob
    #   distance = sqrt(dx^2 + dy^2)
    #
    distances = nsqrt(dxs ** 2 + dys ** 2)
    
    #
    # Make a list of eligible eligible blob pairs
    #
    hypoteni = distances.copy()
    hypoteni[distances < min_hypot] = 0
    
    hypot_nonzero = nonzero(hypoteni)

    ## Prepend separation distance, longest-to-shortest
    #blobs_sorted = [(distances[i,j], i, j) for (i, j) in zip(*hypot_nonzero)]
    
    # Prepend combined pixel size, largest-to-smallest
    blobs_sorted = [(blobs[i].size + blobs[j].size, i, j) for (i, j) in zip(*hypot_nonzero)]

    blobs_sorted.sort(reverse=True)
    
    #
    # check each hypotenuse for an eligible third point
    #
    for (row, (sort_value, i, j)) in enumerate(blobs_sorted):
        #
        # vector theta for hypotenuse (i, j)
        #
        ij_theta = _atan2(dys[i,j], dxs[i,j])
        
        #
        # rotate each blob[k] around blob[i] by -theta, to get a hypotenuse-relative theta for (i, k)
        #
        ik_xs = dxs[i,:] * _cos(-ij_theta) - dys[i,:] * _sin(-ij_theta)
        ik_ys = dxs[i,:] * _sin(-ij_theta) + dys[i,:] * _cos(-ij_theta)
        
        ik_thetas = arctan2(ik_ys, ik_xs)

        ik_thetas = [(blobs[k].size, k, theta) for (k, theta) in enumerate(ik_thetas)]
        ik_thetas.sort(reverse=True)
        
        #
        # check each blob[k] for correct distance ratio
        #
        for (size, k, theta) in ik_thetas:
            ratio = distances[i,k] / distances[i,j]
            
            if theta < min_theta or max_theta < theta:
                continue

            if ratio < min_ratio or max_ratio < ratio:
                continue
            
            if i == j or i == k or j == k:
                continue
            
            yield (i, j, k, ratio, theta)