zero-size array when running imager_func

[lmorabit]

I'm calling the imager_func like this:
zbl = 0.28
cfloor = 0.0028
niter = 300
conv_criteria = 0.0001
out = eh.imager_func( obs, gaussprior, gaussprior, zbl, d1='cphase', d2='camp', s1='gs', s2='gs', alpha_d1=50, alpha_d2=50, clipfloor=cfloor, maxit=niter, stop=conv_criteria )

The gaussprior is a single gaussian.

I get the following error and traceback:

/home/lmorabit/.local/lib/python2.7/site-packages/ehtim/imaging/imager_utils.pyc in imager_func(Obsdata, InitIm, Prior, flux, d1, d2, d3, alpha_d1, alpha_d2, alpha_d3, s1, s2, s3, alpha_s1, alpha_s2, alpha_s3, alpha_flux, alpha_cm, **kwargs)
294 # Print stats
295 print("Initial S_1: %f S_2: %f S_3: %f" % (reg1(ninit), reg2(ninit), reg3(ninit)))
--> 296 print("Initial Chi^2_1: %f Chi^2_2: %f Chi^2_3: %f" % (chisq1(ninit), chisq2(ninit), chisq3(ninit)))
297 print("Initial Objective Function: %f" % (objfunc(xinit)))
298

/home/lmorabit/.local/lib/python2.7/site-packages/ehtim/imaging/imager_utils.pyc in chisq2(imvec)
199
200 def chisq2(imvec):
--> 201 return chisq(imvec, A2, data2, sigma2, d2, ttype=ttype, mask=embed_mask)
202
203 def chisq2grad(imvec):

/home/lmorabit/.local/lib/python2.7/site-packages/ehtim/imaging/imager_utils.pyc in chisq(imvec, A, data, sigma, dtype, ttype, mask)
373 chisq = chisq_cphase(imvec, A, data, sigma)
374 elif dtype == 'camp':
--> 375 chisq = chisq_camp(imvec, A, data, sigma)
376 elif dtype == 'logcamp':
377 chisq = chisq_logcamp(imvec, A, data, sigma)

/home/lmorabit/.local/lib/python2.7/site-packages/ehtim/imaging/imager_utils.pyc in chisq_camp(imvec, Amatrices, clamp, sigma)
739 def chisq_camp(imvec, Amatrices, clamp, sigma):
740 """Closure Amplitudes (normalized) chi-squared"""
--> 741 print( np.min(imvec) )
742 print( np.min(Amatrices[1] ) )
743 clamp_samples = np.abs(np.dot(Amatrices[0], imvec) * np.dot(Amatrices[1], imvec) / (np.dot(Amatrices[2], imvec) * np.dot(Amatrices[3], imvec)))

/usr/lib64/python2.7/site-packages/numpy/core/fromnumeric.pyc in amin(a, axis, out, keepdims)
2370
2371 return _methods._amin(a, axis=axis,
-> 2372 out=out, **kwargs)
2373
2374

/usr/lib64/python2.7/site-packages/numpy/core/_methods.pyc in _amin(a, axis, out, keepdims)
27
28 def _amin(a, axis=None, out=None, keepdims=False):
---> 29 return umr_minimum(a, axis, None, out, keepdims)
30
31 def _sum(a, axis=None, dtype=None, out=None, keepdims=False):

ValueError: zero-size array to reduction operation minimum which has no identity

[klbouman]

Hi Leah, Could you try lowering cfloor to 0 and see what happens? Maybe it is masking out all the pixels in the image.

[lmorabit]

That seems to have worked, thanks. Is there a way to see before running the imager_func what the clipfloor will mask?

[klbouman]

clipfloor in the imager will only optimize pixels in the Prior that initially have an intensity greater than the value you specify. I don't think there is a function right now that will return this mask region. We can add one if you'd like. To see the masked region you could do

mask = gaussprior.copy()
mask.imvec = mask.imvec > clipfloor
mask.display()

This will show the pixels you are asking the imager to optimize as 1.