compare_method_errors_fourier_padding.py

#! python
# -*- coding: utf-8 -*-
"""Compare the different methods to create phase maps."""


import time
import pdb
import traceback
import sys
import numpy as np
from numpy import pi
import matplotlib.pyplot as plt

import pyramid.magcreator as mc
import pyramid.projector as pj
import pyramid.phasemapper as pm
import pyramid.analytic as an
from pyramid.magdata import MagData
from pyramid.phasemap import PhaseMap
import shelve


def phase_from_mag():
    '''Calculate and display the phase map from a given magnetization.
    Arguments:
        None
    Returns:
        None

    '''
    # Create / Open databank:
    data_shelve = shelve.open('../output/method_errors_shelve')

    '''FOURIER PADDING->RMS|DURATION'''
    # Parameters:
    b_0 = 1  # in T
    res = 10.0  # in nm
    dim = (1, 128, 128)
    phi = -pi/4
    padding_list = [0, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
                    16, 17, 18, 19, 20, 21, 22]
    geometry = 'disc'
    # Create magnetic shape:
    if geometry == 'slab':
        center = (0, dim[1]/2-0.5, dim[2]/2-0.5)  # in px (z, y, x) index starts with 0!
        width = (1, dim[1]/2, dim[2]/2)  # in px (z, y, x)
        mag_shape = mc.Shapes.slab(dim, center, width)
        phase_ana = an.phase_mag_slab(dim, res, phi, center, width, b_0)
    elif geometry == 'disc':
        center = (0, dim[1]/2-0.5, dim[2]/2-0.5)  # in px (z, y, x) index starts with 0!
        radius = dim[1] / 4  # in px
        height = 1  # in px
        mag_shape = mc.Shapes.disc(dim, center, radius, height)
        phase_ana = an.phase_mag_disc(dim, res, phi, center, radius, b_0)
    # Project the magnetization data:
    mag_data = MagData(res, mc.create_mag_dist(mag_shape, phi))
    projection = pj.simple_axis_projection(mag_data)
    # Create data:
    data = np.zeros((3, len(padding_list)))
    data[0, :] = padding_list
    for (i, padding) in enumerate(padding_list):
        print 'padding =', padding_list[i]
        # Key:
        key = ', '.join(['Padding->RMS|duration', 'Fourier', 'padding={}'.format(padding_list[i]),
                        'B0={}'.format(b_0), 'res={}'.format(res), 'dim={}'.format(dim),
                        'phi={}'.format(phi), 'geometry={}'.format(geometry)])
        if key in data_shelve:
            data[:, i] = data_shelve[key]
        else:
            start_time = time.time()
            phase_num = pm.phase_mag_fourier(res, projection, b_0, padding_list[i])
            data[2, i] = time.time() - start_time
            phase_diff = phase_ana - phase_num
            PhaseMap(res, phase_diff).display()
            data[1, i] = np.std(phase_diff)
            data_shelve[key] = data[:, i]
    # Plot duration against padding:
    fig = plt.figure()
    axis = fig.add_subplot(1, 1, 1)
    axis.set_yscale('log')
    axis.plot(data[0], data[1])
    axis.set_title('Fourier Space Approach: Variation of the Padding')
    axis.set_xlabel('padding')
    axis.set_ylabel('RMS')
    # Plot RMS against padding:
    fig = plt.figure()
    axis = fig.add_subplot(1, 1, 1)
    axis.plot(data[0], data[2])
    axis.set_title('Fourier Space Approach: Variation of the Padding')
    axis.set_xlabel('padding')
    axis.set_ylabel('duration [s]')
    # Close shelve:
    data_shelve.close()


if __name__ == "__main__":
    try:
        phase_from_mag()
    except:
        type, value, tb = sys.exc_info()
        traceback.print_exc()
        pdb.post_mortem(tb)