nseflipper tool (initial)

"""

import sys

__version__  = "2.0"

__release__  = ".7b1"

__date__     = "Sep 12, 2025"

__release__  = ".7b2"

__date__     = "Sep 15, 2025"

def version(full=False):

    "get pysen version number"

#!/usr/bin/env python

""" script to calculate Mezei flipper curves

"""

import argparse

import logging

import numpy as np

import matplotlib.pyplot as plt

from pysen import version, setup_logger

from pysen.config import INST_POSITIONS, L2, Ltot, HMN, ANGSTROM, DEFAULT_ACCELERATOR_FREQ

from pysen.echo.flippers import FlipperPi, FlipperPi2, tof_curve

flippers = {

    "fpi21"  : FlipperPi2('fpi21',   position =-2.824663, thickness=0.010, turns_density=833.33), #w=0.10 h=0.18, i33

    "fpi21rs": FlipperPi ('fpi21rs', position =-2.283902, thickness=0.010, turns_density=833.33), #w=0.10 h=0.18, i37 

    "fpi"    : FlipperPi ('fpi',     position =-0.146000, thickness=0.013, turns_density=833.33), #w=0.18 h=0.18, i32

    "fpi22rs": FlipperPi ('fpi22rs', position =+2.279194, thickness=0.010, turns_density=821.40), #w=0.28 h=0.28, i38 

    "fpi22"  : FlipperPi2('fpi22',   position =+2.823903, thickness=0.010, turns_density=821.40), #w=0.28 h=0.28, i34

}

def curve_test(axs, name='fpi', **kwargs):

    "test with plots"

    pos  =kwargs.pop('pos', 'p2')

    freq =kwargs.pop('freq', 60.0)

    points=kwargs.pop('points', 163)

    lmax=kwargs.pop('lmax', 8.0)

    compare=kwargs.pop('compare', None)

    scale =kwargs.pop('scale', 1.0)

    log = logging.getLogger()

    L  =  Ltot.get(pos) # [m] source to detector

    L1 =  L - L2 # [m] source to sample

    GAUSS = 1e-4 # T

    B_ext = [ 1.000692*GAUSS, 0, -0.039814*GAUSS ] # ext. field

    #B_ext = [ 0.0, 0.0, 0.0]

    #

    compare_data = None

    if compare is not None:

        try:

            compare_data = np.loadtxt(compare)

        except FileNotFoundError as err:

            log.error("cannot load compare file (%s)",err)

            compare_data = None

    delam = HMN/(freq*L) # wavelengtgh band

    print(f"lambda = ({lmax-delam/ANGSTROM:g} - {lmax:g}) A")

    lmax = lmax*ANGSTROM

    f = flippers.get(name)

    print(f"flipper {f}")

    curve =  tof_curve(f, lmax, delam, points=points, sample_to_source=L1,

                       freq=freq, b_ext=B_ext, rewind=5)

    scurve = curve*f.current(lmax)/scale

    p = axs.plot(scurve,'-', lw=1, label='calc %s' % name)

    if compare is not None:

        axs.plot(compare_data,'s', ms=2, lw=1, label='compare %s' % compare, color=p[0].get_color())

def main():

    "TBD"

    description="<unknown>"

    #

    description='Tool to generate flipper curves'

    parser = argparse.ArgumentParser(description=description)

    parser.set_defaults(name='fpi',

                        pos='p2', freq=DEFAULT_ACCELERATOR_FREQ, points=163, lmax=8.0, scale=1.0,

                        compare=None, loglevel=2, out='.')

    #parser.add_argument('filename', metavar='file', nargs='+', help='file name to process')

    parser.add_argument('--name', '-n', dest='name', choices=flippers.keys(),

                        help='flipper name (default %(default)s)')

    parser.add_argument('--frequency', '-F', dest='freq', type=float,

                        help='accelerator frequency (default %(default)s)')

    parser.add_argument('--wavelength', '-L', dest='lmax', type=float,

                        help='set (max) neutron wavelength in Angstroms (default %(default)s)')

    parser.add_argument('--pos', '-p', dest='pos', choices=INST_POSITIONS,

                        help='instrument position to determine wavelength band (default %(default)s)')

    parser.add_argument('--scale', '-S', dest='scale', type=float,

                        help='current scale factor (default %(default)s)')

    parser.add_argument('--compare', '-c', dest='compare',

                        help='compare with file (default %(default)s)')

    parser.add_argument('--outdir', '-o', dest='out',

                        help='set output directory (default %(default)s)')

    parser.add_argument('--version', action='version',

                        version='%(prog)s pysen={version}'.format(version=version(full=True)))

    parser.add_argument('--verbose', '-v', dest='loglevel', action='count',

                        help='verbose output')

    parser.add_argument('--quiet', '-q', dest='loglevel', action='store_const', const=0,

                        help='verbose output')

    args = parser.parse_args()

    kwargs = vars(args)

    loglevel  = kwargs.pop('loglevel')

    _outdir    = kwargs.pop('out')

    setup_logger(loglevel)

    fig, ax1 = plt.subplots(1,1,figsize=(8,6))

    fig.suptitle(rf'{args.name} $\lambda_{{max}}$={args.lmax:g}$\AA$')

    curve_test(ax1, **kwargs)

    ax1.legend()

    ax1.set_ylabel(r'I (A)')

    ax1.grid()

    plt.show()

if __name__ == "__main__":

    main()

        'console_scripts': [

            'nseplot          = pysen.ui.nseplot:main',

            'nxs2taco         = pysen.inout.nxs2taco:main',

            'nseflipper       = pysen.ui.nseflipper:main',

        ],

      },

      scripts       = [