Example #1
0
    def reset(self):
        self.post = gv_general.chiwedge( wedge = self.pars.get('wedge'),
                chi = self.pars.get('chi')).ravel()
        self.posti= np.dot(gv_general.wedgemat(self.pars.get('wedge')), 
                           gv_general.chimat(self.pars.get('chi'))).T.ravel()

        self.axis = np.array([0,0,-1],np.float)
Example #2
0
def grain_x0(omega, wedge, chi, tx, ty, tz):
    """ Grain origin positions at Omega rotation """
    co = np.cos(np.radians(omega))
    so = np.sin(np.radians(omega))
    x0 = np.zeros((3, omega.shape[0]))
    x0[0] = co * tx - so * ty
    x0[1] = so * tx + co * ty
    x0[2] = tz
    cw = gv_general.chiwedge(chi, wedge)
    x0 = np.dot(cw.T, x0)
    return x0
Example #3
0
def g_to_k(g, omega, wedge, chi):
    """ Rotate g vector to k vector """
    co = np.cos(np.radians(omega))
    so = np.sin(np.radians(omega))
    k = np.zeros((3, len(omega)))
    k[0, :] = co * g[0, :] - so * g[1, :]
    k[1, :] = so * g[0, :] + co * g[1, :]
    k[2, :] = g[2, :]
    cw = gv_general.chiwedge(chi, wedge)
    k = np.dot(cw, k)
    return k
Example #4
0
def k_to_g(k, omega, wedge, chi):
    """ Rotate k vector to g vector """
    #print "k_to_g",k,omega,wedge,chi
    om = np.radians(omega)
    g = np.zeros(k.shape)
    cw = gv_general.chiwedge(chi, wedge)
    cwk = np.dot(cw, k)
    co = np.cos(np.radians(omega))  # 1D
    so = np.sin(np.radians(omega))  # 1D
    g[0, :] = co * cwk[0, :] + so * cwk[1, :]
    g[1, :] = -so * cwk[0, :] + co * cwk[1, :]
    g[2, :] = cwk[2, :]
    return g
Example #5
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 def compute_XLYLZL(self):
     self.peaks_xyz = transform.compute_xyz_lab(
         [self.colfile.sc, self.colfile.fc],
         **self.colfile.parameters.parameters)
     # These are the peak positions in the laboratory frame
     #
     # Now get the beam and peaks in the crystal frame
     wedge = float(self.colfile.parameters.get('wedge'))
     chi = float(self.colfile.parameters.get('chi'))
     self.chiwedge = gv_general.chiwedge(chi, wedge)
     omega = np.radians(self.colfile.omega)
     cosomega = np.cos(omega)
     sinomega = np.sin(omega)
     beam = np.zeros((3, len(omega)), float)
     beam[0, :] = 1.
     self.XB = k_to_g(beam, cosomega, sinomega, self.chiwedge)
     self.XS = k_to_g(self.peaks_xyz, cosomega, sinomega, self.chiwedge)
Example #6
0
def testhklcalc_many(wedge, chi):
    # hklcalc_many
    # apply wedge, chi to axis if necessary

    axis = np.array( [0,0,-1], np.float )
    UBI = np.eye(3).ravel()
    hkl = np.zeros( (len(omega), 3), np.float)
    XL = np.ones( (len(omega), 3), np.float)*1e3
    T = np.array([100,200,300],np.float)
    wvln = 0.254
    pre = np.eye(3).ravel()
    post = gv_general.chiwedge( wedge=wedge, chi=chi ).ravel()
    kc = XL.copy()
    wripaca.hklcalc_many( XL, axis,  omega*np.pi/180, UBI, T, pre, post, hkl, wvln, kc)
    print "axis is",axis
    t, e = transform.compute_tth_eta_from_xyz( XL.T,
        t_x = T[0],
        t_y = T[1],
        t_z = T[2],
        omega = omega,
        wedge = wedge,
        chi = chi
        )
    #print t,e,omega
    ori = transform.compute_grain_origins( omega, wedge=wedge, chi=chi, 
        t_x  = T[0], t_y = T[1], t_z = T[2] )
    print "last origin",ori.T[-1],ori.T[0]
    print "last xl",XL[-1],XL[0]
    kve = transform.compute_k_vectors( t, e, wvln )
    print "last k",kve.T[-1],kve.T[0]
    gve = transform.compute_g_vectors( t, e, omega, wvln, wedge=wedge, chi=chi )
    print "last g",gve.T[-1],gve.T[0]
    htest = np.dot( UBI.reshape(3,3), gve )
    for i in range(len(t)):
        #        print gve[:,i]
        # print hkl[i]

        if ((gve[:,i]-hkl[i])**2).sum() > 1e-10:
            print "FAIL",
            print i,gve[:,i],hkl[i],((gve[:,i]-hkl[i])**2).sum() 
            print wedge,chi
            sys.exit()
    
    print "OK for wedge",wedge,"chi",chi
Example #7
0
 def test_25_30(self):
     """ wedge, chi = 25,30 """
     w, c = 25, 30
     SANITY = False
     if SANITY: print "*" * 80
     om = np.zeros(self.np, np.float)
     g_old = transform.compute_g_vectors(self.tth,
                                         self.eta,
                                         self.omega,
                                         self.wvln,
                                         wedge=w,
                                         chi=c)
     if SANITY: print g_old.shape, "\n", g_old[:, :3]
     k = transform.compute_k_vectors(self.tth, self.eta, self.wvln)
     if SANITY: print "k=", k[:, :3]
     post = gv_general.chiwedge(chi=c, wedge=w)
     g_new = gv_general.k_to_g(k, self.omega, axis=[0, 0, -1], post=post)
     if SANITY: print g_new.shape, g_new[:, :3]
     if SANITY: print "end routine"
     if SANITY: print "*" * 80
     self.assertAlmostEqual(array_diff(g_new, g_old), 0, 6)
Example #8
0
def uncompute_g_vectors(g, wavelength, wedge=0.0, chi=0.0):
    """
    Given g-vectors compute tth,eta,omega
    assert uncompute_g_vectors(compute_g_vector(tth,eta,omega))==tth,eta,omega
    """
    if wedge == chi == 0:
        post = None
    else:
        post = gv_general.wedgechi(wedge=wedge, chi=chi)
    omega1, omega2, valid = gv_general.g_to_k(g,
                                              wavelength,
                                              axis=[0, 0, -1],
                                              pre=None,
                                              post=post)
    # we know g, omega. Compute k as ... ?
    if post is None:
        pre = None
    else:
        pre = gv_general.chiwedge(wedge=wedge, chi=chi).T
    k_one = gv_general.k_to_g(g, omega1, axis=[0, 0, 1], pre=pre, post=None)
    k_two = gv_general.k_to_g(g, omega2, axis=[0, 0, 1], pre=pre, post=None)
    #
    # k[1,:] = -ds*c*sin(eta)
    # ------    -------------   .... tan(eta) = -k1/k2
    # k[2,:] =  ds*c*cos(eta)
    #
    eta_one = np.arctan2(-k_one[1, :], k_one[2, :])
    eta_two = np.arctan2(-k_two[1, :], k_two[2, :])
    #
    #
    ds = np.sqrt(np.sum(g * g, 0))
    s = ds * wavelength / 2.0  # sin theta
    tth = np.degrees(np.arcsin(s) * 2.) * valid
    eta1 = np.degrees(eta_one) * valid
    eta2 = np.degrees(eta_two) * valid
    omega1 = omega1 * valid
    omega2 = omega2 * valid
    return tth, [eta1, eta2], [omega1, omega2]
Example #9
0
def Dcalc(UB, hkls, wedge, chi, wavelength, etao, omega):
    """
    Finds "C"alculated 2thetac, etac, omegac for a grain
    (Note that these do not depend on the grain position)

    UB = 3x3 UB matrix
    hkls = 3xn list of peaks (normally integers)
    wedge = tilt around y under rotation axis
    chi = tilt around beam under rotation axis
    wavelength = of the radiation, scales UB
    etao = observed azimuth values (angle on powder ring)
    omega = observed(?) sample rotation angles

    ???    ysign determines which solution (there are usually two)
    """
    # computed g-vectors
    g = np.dot(UB, hkls)
    assert g.dtype == float
    if 0:
        print(g.shape)
        print(hkls.shape)
        for i in range(10):
            print(g[:, i], end=' ')
            print(hkls[:, i], end=' ')
            print(np.dot(np.linalg.inv(UB), g[:, i]))

    # wedge/chi matrix for axis orientation
    wc = gv_general.wedgechi(wedge=wedge, chi=chi)
    assert wc.dtype == float
    # computed omega angles for reflections
    omega1, omega2, valid = gv_general.g_to_k(g,
                                              wavelength,
                                              axis=[0, 0, -1],
                                              pre=None,
                                              post=wc)
    assert omega1.dtype == float
    # hum - isn't this wc-1 ?
    cwT = gv_general.chiwedge(wedge=wedge, chi=chi).T
    # k vectors, scattering in laboratory at angle omega1/2
    k1 = gv_general.k_to_g(g, omega1, axis=[0, 0, 1], pre=cwT, post=None)
    k2 = gv_general.k_to_g(g, omega2, axis=[0, 0, 1], pre=cwT, post=None)
    assert k1.dtype == float
    # Computed azimuth angles
    #
    # k[1,:] = -ds*c*sin(eta)
    # ------    -------------   .... tan(eta) = -k1/k2
    # k[2,:] =  ds*c*cos(eta)
    #
    eta_one = np.degrees(np.arctan2(-k1[1, :], k1[2, :]))
    eta_two = np.degrees(np.arctan2(-k2[1, :], k2[2, :]))
    #
    # We select the one matching the observed data
    # FIXME - doesn't make sense to do this here
    # pick the solution which is closest to matching in eta/omega
    d1 = angmod(eta_one - etao)
    d2 = angmod(eta_two - etao)
    # Selecting which is the computed value for peaks
    etac = np.where(abs(d1) < abs(d2), eta_one, eta_two)
    omegac = np.where(abs(d1) < abs(d2), omega1, omega2)

    if TESTING > 2:
        err = abs(etac - etao)
        for i in range(len(err)):
            if err[i] < 1:
                continue
            print(i, eta_one[i], eta_two[i], omega1[i], omega2[i])
            print("\t", etao[i], omega[i], etac[i], omegac[i])

    # Two theta angles
    mod_g = np.sqrt((g * g).sum(axis=0))
    tthc = np.degrees(2 * np.arcsin(wavelength * mod_g / 2))
    # Return computed values (no derivatives here)
    return tthc, etac, omegac
Example #10
0
testaxisang()



def anglediff(a1, a2):
    return np.arctan2(np.sin(a1-a2), np.cos(a1-a2))



for wedge, chi in [(0.,0.),(-10.,0.), (11,-15), (0,6)]:
    print "Wedge",wedge,"chi",chi
    print "gve[0] gve[1] gve[2]  om1py  om2py  om1af  om2af  omtrue"
    gve = transform.compute_g_vectors( tth, eta, omega, wvln, wedge, chi )
    gve = gve.T.copy()
    post = gv_general.chiwedge( wedge=wedge, chi=chi ) 
    posti = np.dot(gv_general.wedgemat(wedge), gv_general.chimat(chi)).T

    # don't try to match this as it is wrong!!
    #    tth, eta, omega = transform.uncompute_g_vectors( hkl.T, wvln, 
    #        wedge=wedge,
    #        chi = chi)

    ppre = np.reshape(pre,(3,3))
    ppost = np.reshape(post,(3,3))


    omg1, omg2, valid = gv_general.g_to_k( gve.T, wvln, axis=axis, pre=ppre, post=ppost )
    #print pre
    #print posti.ravel()
    #print axis