.. _axes_grid-demo_floating_axes:

axes_grid example code: demo_floating_axes.py
=============================================



.. plot:: /home/tcaswell/other_source/matplotlib/doc/mpl_examples/axes_grid/demo_floating_axes.py

::

    from matplotlib.transforms import Affine2D
    
    import mpl_toolkits.axisartist.floating_axes as floating_axes
    
    import numpy as np
    import  mpl_toolkits.axisartist.angle_helper as angle_helper
    from matplotlib.projections import PolarAxes
    from mpl_toolkits.axisartist.grid_finder import FixedLocator, MaxNLocator, \
         DictFormatter
    
    def setup_axes1(fig, rect):
        """
        A simple one.
        """
        tr = Affine2D().scale(2, 1).rotate_deg(30)
    
        grid_helper = floating_axes.GridHelperCurveLinear(tr, extremes=(0, 4, 0, 4))
    
        ax1 = floating_axes.FloatingSubplot(fig, rect, grid_helper=grid_helper)
        fig.add_subplot(ax1)
    
        aux_ax = ax1.get_aux_axes(tr)
    
        grid_helper.grid_finder.grid_locator1._nbins = 4
        grid_helper.grid_finder.grid_locator2._nbins = 4
    
        return ax1, aux_ax
    
    
    def setup_axes2(fig, rect):
        """
        With custom locator and formatter.
        Note that the extreme values are swapped.
        """
    
        #tr_scale = Affine2D().scale(np.pi/180., 1.)
    
        tr = PolarAxes.PolarTransform()
    
        pi = np.pi
        angle_ticks = [(0, r"$0$"),
                       (.25*pi, r"$\frac{1}{4}\pi$"),
                       (.5*pi, r"$\frac{1}{2}\pi$")]
        grid_locator1 = FixedLocator([v for v, s in angle_ticks])
        tick_formatter1 = DictFormatter(dict(angle_ticks))
    
        grid_locator2 = MaxNLocator(2)
    
        grid_helper = floating_axes.GridHelperCurveLinear(tr,
                                            extremes=(.5*pi, 0, 2, 1),
                                            grid_locator1=grid_locator1,
                                            grid_locator2=grid_locator2,
                                            tick_formatter1=tick_formatter1,
                                            tick_formatter2=None,
                                            )
    
        ax1 = floating_axes.FloatingSubplot(fig, rect, grid_helper=grid_helper)
        fig.add_subplot(ax1)
    
        # create a parasite axes whose transData in RA, cz
        aux_ax = ax1.get_aux_axes(tr)
    
        aux_ax.patch = ax1.patch # for aux_ax to have a clip path as in ax
        ax1.patch.zorder=0.9 # but this has a side effect that the patch is
                            # drawn twice, and possibly over some other
                            # artists. So, we decrease the zorder a bit to
                            # prevent this.
    
        return ax1, aux_ax
    
    
    def setup_axes3(fig, rect):
        """
        Sometimes, things like axis_direction need to be adjusted.
        """
    
        # rotate a bit for better orientation
        tr_rotate = Affine2D().translate(-95, 0)
    
        # scale degree to radians
        tr_scale = Affine2D().scale(np.pi/180., 1.)
    
        tr = tr_rotate + tr_scale + PolarAxes.PolarTransform()
    
        grid_locator1 = angle_helper.LocatorHMS(4)
        tick_formatter1 = angle_helper.FormatterHMS()
    
        grid_locator2 = MaxNLocator(3)
    
        ra0, ra1 = 8.*15, 14.*15
        cz0, cz1 = 0, 14000
        grid_helper = floating_axes.GridHelperCurveLinear(tr,
                                            extremes=(ra0, ra1, cz0, cz1),
                                            grid_locator1=grid_locator1,
                                            grid_locator2=grid_locator2,
                                            tick_formatter1=tick_formatter1,
                                            tick_formatter2=None,
                                            )
    
        ax1 = floating_axes.FloatingSubplot(fig, rect, grid_helper=grid_helper)
        fig.add_subplot(ax1)
    
        # adjust axis
        ax1.axis["left"].set_axis_direction("bottom")
        ax1.axis["right"].set_axis_direction("top")
    
        ax1.axis["bottom"].set_visible(False)
        ax1.axis["top"].set_axis_direction("bottom")
        ax1.axis["top"].toggle(ticklabels=True, label=True)
        ax1.axis["top"].major_ticklabels.set_axis_direction("top")
        ax1.axis["top"].label.set_axis_direction("top")
    
        ax1.axis["left"].label.set_text(r"cz [km$^{-1}$]")
        ax1.axis["top"].label.set_text(r"$\alpha_{1950}$")
    
    
        # create a parasite axes whose transData in RA, cz
        aux_ax = ax1.get_aux_axes(tr)
    
        aux_ax.patch = ax1.patch # for aux_ax to have a clip path as in ax
        ax1.patch.zorder=0.9 # but this has a side effect that the patch is
                            # drawn twice, and possibly over some other
                            # artists. So, we decrease the zorder a bit to
                            # prevent this.
    
        return ax1, aux_ax
    
    
    
    if 1:
        import matplotlib.pyplot as plt
        fig = plt.figure(1, figsize=(8, 4))
        fig.subplots_adjust(wspace=0.3, left=0.05, right=0.95)
    
        ax1, aux_ax2 = setup_axes1(fig, 131)
        aux_ax2.bar([0, 1, 2, 3], [3, 2, 1, 3])
    
        #theta = np.random.rand(10) #*.5*np.pi
        #radius = np.random.rand(10) #+1.
        #aux_ax1.scatter(theta, radius)
    
    
        ax2, aux_ax2 = setup_axes2(fig, 132)
    
        theta = np.random.rand(10)*.5*np.pi
        radius = np.random.rand(10)+1.
        aux_ax2.scatter(theta, radius)
    
    
        ax3, aux_ax3 = setup_axes3(fig, 133)
    
        theta = (8 + np.random.rand(10)*(14-8))*15. # in degrees
        radius = np.random.rand(10)*14000.
        aux_ax3.scatter(theta, radius)
    
        plt.show()
    
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)