Hi I try to calculate the dark matter angular momentum profile using following routine: ##################################### import matplotlib.pyplot as plt import pylab as pl def _RadiuspcXY(field, data): center = data.get_field_parameter("center") DW = data.pf.domain_right_edge - data.pf.domain_left_edge radius = na.zeros(data["x"].shape, dtype='float64') for i, ax in enumerate('xy'): r = na.abs(data[ax] - center[i]) radius += na.minimum(r, na.abs(DW[i]-r))**2.0 na.sqrt(radius, radius) return radius def _ConvertRadius(data): return data.convert("pc") add_field("RadiuspcXY", function=_RadiuspcXY, validators=[ValidateParameter("center")], convert_function = _ConvertRadius, units=r"\rm{pc}", display_name="RadiusXY") Nbin = 75 rdisk = 2000 hdisk = 10 pf = load("DD0046/DD0046") rmin = 2.0*pf.h.get_smallest_dx()*pf.units['pc']] center = pf.h.find_max("Density")[1] disk = pf.h.disk(center, [0,0,1], rdisk/pf.units['pc'], hdisk/pf.units['pc'] ) profile = BinnedProfile1D(disk, Nbin, "Radiuspc", max(rmin), rdisk, log_space=True, lazy_reader=True, end_collect=False) profile.add_fields('ParticleSpecificAngularMomentumZ') plt.plot(profile['RadiuspcXY'], profile['ParticleSpecificAngularMomentumZ']) And I got the following error message: yt : [INFO ] 2012-10-23 11:16:00,124 Parameters: current_time = 4.600008999 yt : [INFO ] 2012-10-23 11:16:00,124 Parameters: domain_dimensions = [64 64 64] yt : [INFO ] 2012-10-23 11:16:00,125 Parameters: domain_left_edge = [ 0. 0. 0.] yt : [INFO ] 2012-10-23 11:16:00,125 Parameters: domain_right_edge = [ 1. 1. 1.] yt : [INFO ] 2012-10-23 11:16:00,126 Parameters: cosmological_simulation = 0.0 yt : [INFO ] 2012-10-23 11:16:00,138 Getting the binary hierarchy yt : [INFO ] 2012-10-23 11:16:00,168 Finished with binary hierarchy reading yt : [INFO ] 2012-10-23 11:16:00,623 Max Value is 1.55814e-16 at 0.5001935958862305 0.4999227523803749 0.4994192123413048 in grid EnzoGrid_1396 at level 13 (5, 3, 3) Traceback (most recent call last): File "JprofDM.py", line 51, in <module> profile.add_fields('ParticleSpecificAngularMomentumZ') File "/home/jhchoi/common/lib/python2.7/site-packages/yt-2.4-py2.7-linux-x86_64.egg/yt/data_objects/profiles.py", line 168, in add_fields self._lazy_add_fields(fields, weight, accumulation) File "/home/jhchoi/common/lib/python2.7/site-packages/yt-2.4-py2.7-linux-x86_64.egg/yt/data_objects/profiles.py", line 108, in _lazy_add_fields args=args, check_cut=True) File "/home/jhchoi/common/lib/python2.7/site-packages/yt-2.4-py2.7-linux-x86_64.egg/yt/data_objects/profiles.py", line 55, in save_state tr = func(*args, **kwargs) File "/home/jhchoi/common/lib/python2.7/site-packages/yt-2.4-py2.7-linux-x86_64.egg/yt/data_objects/profiles.py", line 275, in _bin_field source_data = source_data[mi] ValueError: too many boolean indices What can be the problem? I compute the gas Angular momentum by simply change ParticleSpecificAngularMomentumZ to SpecificAngularMomentumZ, it works. As a result, I suspect the way to handle the particles. Thanks in advance, Junhwan -- -------------------------------------------------------------- Jun-Hwan Choi, Ph.D. Department of Physics and Astronomy, University of Kentucky Tel: (859) 897-6737 Fax: (859) 323-2846 Email: jhchoi@pa.uky.edu URL: http://www.pa.uky.edu/~jhchoi --------------------------------------------------------------