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.

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"

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()

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)