Add Gwyddion gwy file import/export

[mpanighel]

Using the gwyfile Python package.

Export example from RHK .sm4:

from gwyfile.objects import GwyContainer, GwyDataField, GwySIUnit
obj = GwyContainer()

filename = 'VT210531_A1_0025.sm4'
f = spym.load(filename)

for i, ch in enumerate(f.data_vars):

    datarr = f[ch]

    si_units_xy = GwySIUnit()
    si_units_z = GwySIUnit()
    meta = GwyContainer()
    df = GwyDataField(datarr.values)

    si_units_xy['unitstr'] = datarr.attrs['RHK_Xunits']
    si_units_z['unitstr'] = datarr.attrs['RHK_Zunits']

    for k,v in datarr.attrs.items():
        meta[k] = str(v)

    df['xres'] = datarr.attrs['RHK_Xsize']
    df['yres'] = datarr.attrs['RHK_Ysize']
    df['xreal'] = abs( datarr.attrs['RHK_Xscale'] * datarr.attrs['RHK_Xsize'])
    df['yreal'] = abs( datarr.attrs['RHK_Yscale'] * datarr.attrs['RHK_Ysize'])
    df['si_unit_xy'] = si_units_xy
    df['si_unit_z'] = si_units_z

    data_path = "/{}/data".format(i)
    meta_path = "/{}/meta".format(i)
    obj[data_path] = df
    obj[data_path+'/title'] = ch
    obj[meta_path] = meta

    if i==0:
        obj['/0/data/visible'] = True

obj.tofile(filename+'.gwy')

[mpanighel]

Import example:

from xarray import Dataset, DataArray
import gwyfile
import numpy as np

filename = 'VT210531_A1_0032.sm4.gwy'
obj = gwyfile.load(filename)

ds = Dataset()

i = 0

while True:
    data_path = "/{}/data".format(i)
    meta_path = "/{}/meta".format(i)

    try:
        name = obj[data_path+"/title"]
    except KeyError:
        break

    xres = obj[data_path]["xres"]
    yres = obj[data_path]["yres"]
    xreal = obj[data_path]["xreal"]
    yreal = obj[data_path]["yreal"]

    data = obj[data_path]["data"].reshape(xres, yres)
    attrs = dict(obj[meta_path])
    for k,v in attrs.items():
        if k in ["scaling_factor", "offset", "bias", "setpoint", "feedback_pgain", "scan_angle", "time_per_point"]:
            attrs[k] = float(v)

    coords = [("x", np.linspace(0.0, xreal, num=xres)),
              ("y", np.linspace(0.0, yreal, num=yres))]

    ds[name] = DataArray(data,
                         coords=coords,
                         attrs=attrs)

    i += 1