PGFPlotsXbughelp wanted
説明
using Plots
pgfplots()
plot(linspace(0, 2pi, 360), linspace(-1, 3, 360), proj = :polar)

The interpretation of axis limits which contain negative numbers is weird instead of the radial axis starting at -1 it starts at 0 and interprets the negative limit as a literal negative radius. This leads to odd looking plots like above. Seems like the main issue for PGFPlots is that it always gives the origin of the polar plot a radius value of 0. Similarly when axis limits do not start at 0 you get
plot(linspace(0, 2pi, 360), linspace(2, 3, 360), proj = :polar)
