Making a Layer of the nematic's angles in napari 
================================================


.. code-block::

    import numpy as np
    from tifffile import imread
    import napari
    from orientationfield import of_script
    from orientationfield import nematicfield

    viewer = napari.Viewer()

    # load data
    data = imread("path/to/data")

    # define box sizes
    bx, by = (4, 4)

    # create layer (crop to make image size divisible by box size)
    img = viewer.add_image(data[data.shape[0]%bx:, data.shape[1]%by:])

    # compute nematic field of the image
    of_script.compute_nematic_field(
        img=img,
        sigma=3
    )

    # extract per box angles
    nem_field = img.metadata["nematic_field"]
    angles = np.zeros_like(nem_field[:,:,0,0])
    for box, (x1, x2, y1, y2) in nematicfield.tesselate(nem_field, bx, by):
        angles[x1:x2, y1:y2] = nematicfield.extract(np.mean(box, (0, 1)))[1]

    # add multiplicately blended HSV-colored layer of angles
    multicolor_filter = viewer.add_image(angles, colormap="hsv", blending="multiplicative")


    napari.run()