这不是更改 maximum_fft_size 参数的地方。有关如何使用 GSParams 对象和更新参数的示例,请参见 demo7。GSObject 的文档字符串中还有一个示例:
>>> gal = galsim.Sersic(n=4, half_light_radius=4.3)
>>> psf = galsim.Moffat(beta=3, fwhm=2.85)
>>> conv = galsim.Convolve([gal,psf])
>>> im = galsim.Image(1000,1000, scale=0.05) # Note the very small pixel scale!
>>> im = conv.drawImage(image=im) # This uses the default GSParams.
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "galsim/base.py", line 1236, in drawImage
image.added_flux = prof.SBProfile.draw(imview.image, gain, wmult)
RuntimeError: SB Error: fourierDraw() requires an FFT that is too large, 6144
If you can handle the large FFT, you may update gsparams.maximum_fft_size.
>>> big_fft_params = galsim.GSParams(maximum_fft_size=10240)
>>> conv = galsim.Convolve([gal,psf],gsparams=big_fft_params)
>>> im = conv.drawImage(image=im) # Now it works (but is slow!)
>>> im.write('high_res_sersic.fits')