Hi everyone, I defined two fields, say, FieldOne and FieldTwo, to make 2D phase plot. FieldOne is logarithmic by default, FieldTwo is linear (i.e., I set take_log=False in add_field). I want to produce a phase plot with logarithmic bins for FieldOne and linear bins for FieldTwo, where the range of FieldTwo is [-10,10] I thought that pc.add_phase_object(dd, ["FieldOne", "FieldTwo", "CellMass"], weight=None, x_bins=100,y_bins=100, \ x_bounds=[1e0,1e10], y_bounds=[-10,10]) might do the job, but yt returns the error message: Warning: invalid value encountered in log10 yt : [ERROR ] 2011-09-30 16:55:05,610 Your min/max values for x, y have given me a nan. yt : [ERROR ] 2011-09-30 16:55:05,610 Usually this means you are asking for log, with a zero bound. Traceback (most recent call last): File "stability.py", line 352, in <module> x_bounds=[1e0,1e10], y_bounds=[-10,10]) File "/nics/e/sw/analysis/yt/2.1/sles11.1_gnu4.3.4/src/yt-hg/yt/visualization/plot_collection.py", line 1149, in add_phase_object lazy_reader) File "/nics/e/sw/analysis/yt/2.1/sles11.1_gnu4.3.4/src/yt-hg/yt/data_objects/profiles.py", line 408, in __init__ raise ValueError ValueError It appears that add_phase_object treats FieldTwo logarithmically, although it is linear. So how can I do a log-linear phase plot? Best, Wolfram