========================
Getting Started
========================

Generating a basic image with ``ufig`` can be done by building up a
context of the ``ivy`` workflow engine. Then, at least two plugins need
to be called to compute the PSF at each object and render the image.

.. code:: python

    import ivy
    import numpy as np

    ctx = ivy.context.create_ctx(
        parameters=ivy.load_configs("ufig.config.common")
    )

    ctx.parameters.catalog_precision=np.float32
    ctx.parameters.size_x = 100
    ctx.parameters.size_y = 100

    ctx.numgalaxies = 3
    ctx.galaxies = ivy.context.create_ctx(
        x=np.array([10, 40, 70]),
        y=np.array([30, 80, 20]),
        nphot=np.array([1e4, 1e5, 1e3]),
        r50=np.array([3, 5, 1]),
        sersic_n=np.array([1, 2, 3]),
        e1=np.array([-0.1, 0.1, 0]),
        e2=np.array([-0.5, 0.3, 0.2]),
        psf_beta=2,
        psf_e1=np.array([0.0, 0.0, 0.0]),
        psf_e2=np.array([0.0, 0.0, 0.0]),
        psf_f1=np.array([0.0, 0.0, 0.0]),
        psf_f2=np.array([0.0, 0.0, 0.0]),
        psf_g1=np.array([0.0, 0.0, 0.0]),
        psf_g2=np.array([0.0, 0.0, 0.0]),
        psf_kurtosis=np.array([0.0, 0.0, 0.0]),

    )

    ctx.image = np.zeros((ctx.parameters.size_x, ctx.parameters.size_y))
    ctx.current_filter="i"

.. code:: python

    from ufig.plugins import render_galaxies_flexion, add_psf

    plugin_psf = add_psf.Plugin(ctx)
    plugin_psf()

    plugin_rendering = render_galaxies_flexion.Plugin(ctx)
    plugin_rendering()



.. code:: python

    from astropy.io import fits
    from astropy.visualization import ImageNormalize, LogStretch
    from astropy.visualization.mpl_normalize import ImageNormalize
    from astropy.visualization import PercentileInterval
    import matplotlib.pyplot as plt

    interval = PercentileInterval(95)
    vmin, vmax = interval.get_limits(ctx.image)
    norm = ImageNormalize(vmin=vmin, vmax=vmax, stretch=LogStretch())

    plt.imshow(ctx.image, cmap='gray', norm=norm)



.. image:: output_3_1.png