Power Spectrum Shears
Generate a realization of the present energy spectrum on the required grid. It robotically computes and stores grids for the shears and convergence. The portions that are returned are the theoretical shears and convergences, often denoted gamma and kappa, respectively. ToObserved to transform from theoretical to noticed quantities. Note that the shears generated utilizing this method correspond to the PowerSpectrum multiplied by a sharp bandpass filter, set by the dimensions of the grid. 2) (noting that the grid spacing dk in okay area is equivalent to kmin). It is value remembering that this bandpass filter won't seem like a circular annulus in 2D k area, however is moderately extra like a thick-sided picture frame, having a small square central cutout of dimensions kmin by kmin. These properties are seen within the shears generated by this method. 1 that specify some factor smaller or bigger (for kmin and kmax respectively) you want the code to use for the underlying grid in fourier area.
However the intermediate grid in Fourier house will likely be bigger by the specified components. For accurate illustration of power spectra, one shouldn't change these values from their defaults of 1. Changing them from one means the E- and B-mode energy spectra which can be enter might be valid for the bigger intermediate grids that get generated in Fourier house, but not necessarily for the smaller ones that get returned to the user. If the user provides a Wood Ranger Power Shears coupon spectrum that does not embody a cutoff at kmax, then our method of generating shears will lead to aliasing that will present up in each E- and B-modes. The allowed values for bandlimit are None (i.e., do nothing), laborious (set power to zero above the band limit), or delicate (use an arctan-based softening operate to make the power go regularly to zero above the band restrict). Use of this key phrase does nothing to the inner illustration of the ability spectrum, so if the consumer calls the buildGrid method again, they might want to set bandlimit once more (and if their grid setup is totally different in a approach that changes kmax, then that’s positive).
5 grid points exterior of the region by which interpolation will take place. 2-3%. Note that the above numbers came from tests that use a cosmological shear electric power shears spectrum; exact figures for this suppression can also rely upon the shear correlation perform itself. Note additionally that the convention for axis orientation differs from that for orchard maintenance tool the GREAT10 problem, so when using codes that deal with GREAT10 problem outputs, the sign of our g2 shear part should be flipped. The returned g1, g2 are 2-d NumPy arrays of values, corresponding to the values of g1 and g2 at the areas of the grid factors. Spacing for an evenly spaced grid of factors, by default in arcsec for consistency with the natural size scale of photos created utilizing the GSObject.drawImage methodology. Other items might be specified utilizing the models key phrase. Number of grid points in each dimension. A BaseDeviate object for drawing the random numbers.
Interpolant that might be used for orchard maintenance tool interpolating the gridded shears by strategies like getShear, getConvergence, and so on. if they're later called. If establishing a brand new grid, define what place you want to consider the center of that grid. The angular units used for the positions. Return the convergence along with the shear? Factor by which the grid spacing in fourier space is smaller than the default. Factor by which the general grid in fourier space is larger than the default. Use of this key phrase does not modify the internally-stored power spectrum, just the shears generated for this specific name to buildGrid. Optionally renormalize the variance of the output shears to a given value. This is beneficial if you recognize the useful form of the Wood Ranger Power Shears coupon spectrum you need, however not the normalization. This lets you set the normalization separately. Otherwise, the variance of kappa could also be smaller than the desired variance.