make_slope_map#

synthesizAR.analysis.make_slope_map(dem, temperature_bounds=None, max_upper_bound=None, em_threshold=None, rsquared_tolerance=0.5, iterate_bounds=False, mask_negative=False)[source]#

Calculate emission measure slope \(a\) in each pixel

Create map of emission measure slopes by fitting \(\mathrm{EM}\sim T^a\) for a given temperature range. Additionally, the “goodness-of-fit” is evaluated using the correlation coefficient, \(r^2=1 - R_1/R_0\), where \(R_1\) and \(R_0\) are the residuals from the first and zeroth order polynomial fits, respectively. We mask the slope if \(r^2\) is less than rsquared_tolerance.

Parameters:

  • dem (ndcube.NDCube)

  • temperature_bounds (Quantity, optional) – Range over which to fit the EM distribution. Defaults to the temperature at which the EM distribution is peaked and 25% of that value.

  • em_threshold (Quantity, optional) – Mask slope if the total emission measure in a pixel is below this value

  • rsquared_tolerance (float, optional) – Mask any slopes with a correlation coefficient, \(r^2\), below this value

  • mask_negative (bool) – Mask the pixel if the slope is negative.