# Plot dropout regions on the flatmap¶

A dropout region is a region with very low EPI signal. In pycortex a crosshatch is used to display such dropout regions.

The crosshatches are created using the reference nifti image file with a threshold. Setting the with_dropout=True parameter in quickflat.make_figure takes the reference nifti image file and computes a thresholded version of this using the following formula:

FIXME: .. code-block:: python

rawdata[rawdata==0] = np.mean(rawdata[rawdata!=0]) normdata = (rawdata - rawdata.min()) / (rawdata.max() - rawdata.min()) normdata = (1 - normdata) ** power

import cortex
import numpy as np
np.random.seed(1234)

# Create a random pycortex Volume