igorwriter 0.5.0

Write IGOR binary (.ibw) or text (.itx) files from numpy array

IgorWriter

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Write Igor Binary Wave (.ibw) or Igor Text (.itx) files from numpy array

Features

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• Compatible with multi-dimensional arrays (up to 4 dimensions)

• Supported numpy data types: uint, int, float, complex, bool, str, bytes, datetime64

• Data units (IgorWave.set_datascale)

• Dimension scaling (IgorWave.set_dimscale)

• Dimension labels (IgorWave.set_dimlabel)

Installation

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$ pip install igorwriter

Usage

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Basic usage

>>> import numpy as np

>>> from igorwriter import IgorWave

>>> array = np.array([1,2,3,4,5,6])

>>> # make IgorWave objects

>>> wave = IgorWave(array, name='mywave')

>>> wave2 = IgorWave(array.astype(np.float32), name='mywave2')

>>> # save data

>>> wave.save('mywave.ibw')

>>> wave.save_itx('mywave.itx')

>>> with open('multi_waves.itx', 'w') as fp:

>>>     # Igor Text files can contain multiples waves per file

>>>     wave.save_itx(fp)

>>>     wave2.save_itx(fp)

Data units, dimension scaling

>>> wave.set_datascale('DataUnit')

>>> wave.set_dimscale('x', 0, 0.01, 's')

A two-dimensional array with dimension labels

>>> a2 = np.random.random((10, 3))

>>> wave = IgorWave(a2, name='wave2d')

>>> # you may set optional dimension labels

>>> wave.set_dimlabel(0, -1, 'points') # label for entire rows

>>> wave.set_dimlabel(1, -1, 'values') # label for entire columns

>>> wave.set_dimlabel(1, 0, 'ValueA')  # label for column 0

>>> wave.set_dimlabel(1, 1, 'ValueB')  # label for column 1

>>> wave.set_dimlabel(1, 2, 'ValueC')  # label for column 2

>>> wave.save('my2dwave.ibw')

Unicode support

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From igorwriter 0.5.0, IgorWave stores texts with utf-8 encoding.

If you use Igor Pro 6 or older and want to use non-ascii characters, set unicode=False when calling IgorWave().

It will fall back to system text encoding (Windows-1252, Shift JIS, etc.).

Wave Names

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There are restrictions on object names in IGOR. From v0.2.0, this package deals with illegal object names.

>>> wave = IgorWave(array, name='wave:0', on_errors='fix')  # fix illegal names automatically

RenameWarning: name ‘wave:0’ is fixed as ‘wave_0’ (reason: name must not contain “ ‘ : ; or any control characters.)

>>> wave.name

‘wave_0’

>>> wave = IgorWave(array, name='wave:0', on_errors='raise')  # raise errors

Traceback (most recent call last):

…

InvalidNameError: name must not contain “ ‘ : ; or any control characters.

Pint integration

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If Pint Quantity objects are passed to IgorWave, data units will be set automatically.

>>> import pint

>>> ureg = pint.UnitRegistry()

>>> w = IgorWave([3, 4] * ureg.meter / ureg.second, name='wave_with_units')

>>> w.save_itx('wave_with_units.itx')

…

X SetScale d,0,0,”m / s”,’wave_with_units’

X SetScale /P x,0.0,1.0,””,’wave_with_units’

Pandas integration

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You can easily export DataFrame objects with convenience functions.

>>> from igorwriter import utils

>>> utils.dataframe_to_itx(df, 'df.itx')   # all Series are exported in one file

>>> waves = utils.dataframe_to_ibw(df, prefix='df_bin')   # each Series is saved in a separate file, <prefix>_<column>.ibw

>>> waves  # dictionary of generated IgorWaves. You can change wave names, set data units, set dimension scaling, etc.

{‘col1’: <IgorWave ‘col1’ at 0x…>, ‘col2’: …}

IgorWriter tries to convert index info on pandas.Series objects.

• If the index is evenly-spaced, wave dimension scaling is set accordingly.

• Index names are interpreted as the dimension labels.

Notes on Image Plots

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Image Plot in IGOR and imshow in matplotlib use different convention for x and y axes:

• Rows as x, columns as y (IGOR)

• Columns as x, rows as y (Matplotlib)

Thus, image parameter was introduced in save() and save_itx() methods.

If you use e.g.

>>> wave.save('path.ibw', image=True)

plt.imshow and Image Plot will give the same results.

Changelog

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v0.5.0 (2023-07-08)

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• UTF-8 as default encoding. You can instead use system text encoding by setting unicode=False to IgorWave().

• Automatic conversion from pandas index to dimension scaling.

• Exporting 64-bit integer waves (requires Igor Pro 7 or later).

• BUG FIX: Igor Text files created from np.bool_ arrays were broken.

v0.4.1 (2023-07-02)

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• Added support for np.str_, np.bytes_ arrays.

• Automatic type conversion for np.object_ arrays.

• Added support for dimension scaling (IgorWave.set_simlabel).

v0.3.0 (2019-11-16)

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• Added utils.dict_to_{ibw, itx}

• Set datascale automatically for pint Quantity object.

• Added support for np.datetime64 array.

v0.2.3 (2019-11-09)

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• Added support for 64-bit integers (by automatically casting onto 32-bit integers on save).

v0.2.0 (2019-11-08)

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• Added utilities for pandas (utils.dataframe_to_{ibw, itx} ).

• Added unittest scripts.

• Added wave name validator.

• BUG FIX: long (> 3 bytes) units for dimension scaling were ignored in

  save_itx()

• IgorWriter now uses system locale encoding rather than ASCII (the default behavior of

  IGOR Pro prior to ver. 7.00)