.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/plot_image2d.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_auto_examples_plot_image2d.py>`
        to download the full example code.

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

.. _sphx_glr_auto_examples_plot_image2d.py:


2D Image with Histogram
=======================

Display a 2-D image with physical axes, a colourmap, and an interactive
histogram below — all wired together with draggable threshold widgets.

Layout
------
A :class:`~anyplotlib.figure_plots.GridSpec` with two rows puts the image
on top and a bar-chart histogram below.  Two
:class:`~anyplotlib.widgets.VLineWidget` handles on the histogram mark the
``display_min`` / ``display_max`` thresholds; dragging them updates the
image colour scale in real time.

Key bindings on the image panel: **R** reset view · **C** toggle colorbar ·
**L** / **S** cycle colour-scale modes.

.. GENERATED FROM PYTHON SOURCE LINES 19-100

.. code-block:: Python

    import numpy as np
    import anyplotlib as apl


    rng = np.random.default_rng(1)

    # ── Synthetic diffraction pattern ─────────────────────────────────────────────
    N = 256
    x = np.linspace(-5, 5, N)   # physical axis in nm
    y = np.linspace(-5, 5, N)
    XX, YY = np.meshgrid(x, y)
    R = np.sqrt(XX ** 2 + YY ** 2)


    def _ring(r, r0, width, amp):
        return amp * np.exp(-0.5 * ((r - r0) / width) ** 2)


    image = (
        _ring(R, 0.0, 0.30, 1.00)    # central spot
        + _ring(R, 2.1, 0.15, 0.55)  # first-order ring
        + _ring(R, 4.2, 0.15, 0.25)  # second-order ring
        + rng.normal(scale=0.04, size=(N, N))
    )

    # ── Layout: image (top, 3×) + histogram bar chart (bottom, 1×) ────────────────
    gs = apl.GridSpec(2, 1, height_ratios=[3, 1])
    fig = apl.Figure(figsize=(500, 640))
    ax_img  = fig.add_subplot(gs[0, 0])
    ax_hist = fig.add_subplot(gs[1, 0])

    # ── Image panel ───────────────────────────────────────────────────────────────
    v = ax_img.imshow(image, axes=[x, y], units="nm")
    v.set_colormap("inferno")

    vmin_init = float(image.min())
    vmax_init = float(image.max())
    v.set_clim(vmin=vmin_init, vmax=vmax_init)

    # First-order spot markers
    dx = x[1] - x[0]


    def phys_to_px(val):
        return (np.asarray(val) - x[0]) / dx


    spot_nm = np.array([[ 2.1,  0.0], [-2.1,  0.0],
                        [ 0.0,  2.1], [ 0.0, -2.1]])
    spot_px = np.column_stack([phys_to_px(spot_nm[:, 0]),
                               phys_to_px(spot_nm[:, 1])])
    v.add_circles(spot_px, name="spots", radius=7,
                  edgecolors="#00e5ff", facecolors="#00e5ff22",
                  labels=["g1", "g1_bar", "g2", "g2_bar"])

    # ── Histogram bar chart ────────────────────────────────────────────────────────
    counts, edges = np.histogram(image.ravel(), bins=64)
    bin_centers   = 0.5 * (edges[:-1] + edges[1:])

    h = ax_hist.bar(counts, x_centers=bin_centers, orient="v",
                    color="#4fc3f7", y_units="count")

    # ── Draggable threshold handles on the histogram ──────────────────────────────
    wlo = h.add_vline_widget(vmin_init, color="#ff6e40")   # low-threshold handle
    whi = h.add_vline_widget(vmax_init, color="#ffffff")   # high-threshold handle


    @wlo.on_release
    def _apply_low(event):
        """Update image display_min when the low handle is released."""
        v.set_clim(vmin=event.x)


    @whi.on_release
    def _apply_high(event):
        """Update image display_max when the high handle is released."""
        v.set_clim(vmax=event.x)


    fig





.. raw:: html

    <div style="display:block;text-align:center;line-height:0;margin:12px 0;"><iframe src="../_static/viewer_widgets/sphx_glr_plot_image2d_001.html" frameborder="0" scrolling="no" style="width:516px;height:656px;border:none;overflow:hidden;display:inline-block;max-width:100%;"></iframe></div>






.. GENERATED FROM PYTHON SOURCE LINES 101-105

Adjust colour map
------------------
:meth:`~anyplotlib.figure_plots.Plot2D.set_colormap` switches the palette;
:meth:`~anyplotlib.figure_plots.Plot2D.set_clim` adjusts the display range.

.. GENERATED FROM PYTHON SOURCE LINES 105-110

.. code-block:: Python


    v.set_colormap("viridis")
    v.set_clim(vmin=0.0, vmax=0.8)

    fig




.. raw:: html

    <div style="display:block;text-align:center;line-height:0;margin:12px 0;"><iframe src="../_static/viewer_widgets/sphx_glr_plot_image2d_002.html" frameborder="0" scrolling="no" style="width:516px;height:656px;border:none;overflow:hidden;display:inline-block;max-width:100%;"></iframe></div>







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

   **Total running time of the script:** (0 minutes 0.107 seconds)


.. _sphx_glr_download_auto_examples_plot_image2d.py:

.. only:: html

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

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

      :download:`Download Jupyter notebook: plot_image2d.ipynb <plot_image2d.ipynb>`

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

      :download:`Download Python source code: plot_image2d.py <plot_image2d.py>`

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

      :download:`Download zipped: plot_image2d.zip <plot_image2d.zip>`


.. only:: html

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

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