.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_gallery/text/moving_label.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download__gallery_text_moving_label.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr__gallery_text_moving_label.py:


Moving TextGraphic label
========================

A TextGraphic that labels a point on a line and another TextGraphic that moves along the line on every draw.

.. GENERATED FROM PYTHON SOURCE LINES 7-84



.. image-sg:: /_gallery/text/images/sphx_glr_moving_label_001.webp
   :alt: moving label
   :srcset: /_gallery/text/images/sphx_glr_moving_label_001.webp
   :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    /home/runner/work/fastplotlib/fastplotlib/fastplotlib/graphics/features/_base.py:18: UserWarning: casting float64 array to float32
      warn(f"casting {array.dtype} array to float32")







|

.. code-block:: Python


    # test_example = false

    import numpy as np
    import fastplotlib as fpl

    # create a sinc wave
    xs = np.linspace(-2 * np.pi, 2 * np.pi, 200)
    ys = np.sinc(xs)

    data = np.column_stack([xs, ys])

    # create a figure
    figure = fpl.Figure(size=(700, 450))

    # sinc wave
    line = figure[0, 0].add_line(data, thickness=2)

    # position for the text label on the peak
    pos = (0, max(ys), 0)

    # create label for the peak
    text_peak = figure[0, 0].add_text(
        f"peak  ",
        font_size=20,
        anchor="bottom-right",
        offset=pos
    )

    # add a point on the peak
    point_peak = figure[0, 0].add_scatter(np.asarray([pos]), sizes=10, colors="r")

    # create a text that will move along the line
    text_moving = figure[0, 0].add_text(
        f"({xs[0]:.2f}, {ys[0]:.2f})  ",
        font_size=16,
        outline_color="k",
        outline_thickness=1,
        anchor="top-center",
        offset=(*data[0], 0)
    )
    # a point that will move on the line
    point_moving = figure[0, 0].add_scatter(np.asarray([data[0]]), sizes=10, colors="magenta")


    index = 0
    def update():
        # moves the text and point before every draw
        global index
        # get the new position
        new_pos = (*data[index], 0)

        # move the text and point to the new position
        text_moving.offset = new_pos
        point_moving.data[0] = new_pos

        # set the text to the new position
        text_moving.text = f"({new_pos[0]:.2f}, {new_pos[1]:.2f})"

        # increment index
        index += 1
        if index == data.shape[0]:
            index = 0


    # add update as an animation functions
    figure.add_animations(update)

    figure[0, 0].axes.visible = False
    figure.show(maintain_aspect=False)


    # NOTE: `if __name__ == "__main__"` is NOT how to use fastplotlib interactively
    # please see our docs for using fastplotlib interactively in ipython and jupyter
    if __name__ == "__main__":
        print(__doc__)
        fpl.loop.run()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 12.665 seconds)


.. _sphx_glr_download__gallery_text_moving_label.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: moving_label.ipynb <moving_label.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: moving_label.py <moving_label.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: moving_label.zip <moving_label.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_