Bootstraping error

Simple example of bootstrap on G2 dataset from the N2CLS GTO.

First import the nikamap.analysis.Bootstrap class

from pathlib import Path
from nikamap import Bootstrap

This define the root directory where all the data …

DATA_DIR = Path("/data/NIKA/Reduced/G2_COMMON_MODE_ONE_BLOCK/v_1")

can be retrieved using a simple regular expression

filenames = list(DATA_DIR.glob("*/map.fits"))
filenames

Generate a bootstrap dataset for all the maps.

Note

At the moment, this is very memory demanding as we use `map_size * (len(filenames) + n_bootstrap))`

nm = Bootstrap(filenames, n_bootstrap=200, ipython_widget=True)

In the resulting nikamap.NikaMap object, the uncertainty as been computed using the bootstrap technique.

Warning

The resulting uncertainty map could still be biased, see https://gitlab.lam.fr/N2CLS/NikaMap/issues/4

_ = nm.plot_SNR(cbar=True)