"""
==================
floating_axis demo
==================

Axis within rectangular frame.

The following code demonstrates how to put a floating polar curve within a
rectangular box. In order to get a better sense of polar curves, please look at
:doc:`/gallery/axisartist/demo_curvelinear_grid`.
"""

import matplotlib.pyplot as plt
import numpy as np

from matplotlib.projections import PolarAxes
from matplotlib.transforms import Affine2D
from mpl_toolkits.axisartist import GridHelperCurveLinear, HostAxes
import mpl_toolkits.axisartist.angle_helper as angle_helper


def curvelinear_test2(fig):
    """Polar projection, but in a rectangular box."""
    # see demo_curvelinear_grid.py for details
    grid_helper = GridHelperCurveLinear(
        Affine2D().scale(np.pi / 180., 1.) + PolarAxes.PolarTransform(),
        extreme_finder=angle_helper.ExtremeFinderCycle(
            20, 20,
            lon_cycle=360, lat_cycle=None,
            lon_minmax=None, lat_minmax=(0, np.inf),
        ),
        grid_locator1=angle_helper.LocatorDMS(12),
        tick_formatter1=angle_helper.FormatterDMS(),
    )
    ax1 = fig.add_subplot(axes_class=HostAxes, grid_helper=grid_helper)

    # Now create floating axis

    # floating axis whose first coordinate (theta) is fixed at 60
    ax1.axis["lat"] = axis = ax1.new_floating_axis(0, 60)
    axis.label.set_text(r"$\theta = 60^{\circ}$")
    axis.label.set_visible(True)

    # floating axis whose second coordinate (r) is fixed at 6
    ax1.axis["lon"] = axis = ax1.new_floating_axis(1, 6)
    axis.label.set_text(r"$r = 6$")

    ax1.set_aspect(1.)
    ax1.set_xlim(-5, 12)
    ax1.set_ylim(-5, 10)

    ax1.grid(True)


fig = plt.figure(figsize=(5, 5))
curvelinear_test2(fig)
plt.show()