def show_chip_distinctiveness_plot(chip, kpts, dstncvs, fnum=1, pnum=None):
    import plottool as pt
    pt.figure(fnum, pnum=pnum)
    ax = pt.gca()
    divider = pt.ensure_divider(ax)
    #ax1 = divider.append_axes("left", size="50%", pad=0)
    ax1 = ax
    ax2 = divider.append_axes("bottom", size="100%", pad=0.05)
    #f, (ax1, ax2) = pt.plt.subplots(1, 2, sharex=True)
    cmapstr = 'rainbow'  # 'hot'
    color_list = pt.df2.plt.get_cmap(cmapstr)(ut.norm_zero_one(dstncvs))
    sortx = dstncvs.argsort()
    #pt.df2.plt.plot(qfx2_dstncvs[sortx], c=color_list[sortx])
    pt.plt.sca(ax1)
    pt.colorline(np.arange(len(sortx)), dstncvs[sortx],
                 cmap=pt.plt.get_cmap(cmapstr))
    pt.gca().set_xlim(0, len(sortx))
    pt.dark_background()
    pt.plt.sca(ax2)
    pt.imshow(chip, darken=.2)
    # MATPLOTLIB BUG CANNOT SHOW DIFFERENT ALPHA FOR POINTS AND KEYPOINTS AT ONCE
    #pt.draw_kpts2(kpts, pts_color=color_list, ell_color=color_list, ell_alpha=.1, ell=True, pts=True)
    #pt.draw_kpts2(kpts, color_list=color_list, pts_alpha=1.0, pts_size=1.5,
    #              ell=True, ell_alpha=.1, pts=False)
    ell = ut.get_argflag('--ell')
    pt.draw_kpts2(kpts, color_list=color_list, pts_alpha=1.0, pts_size=1.5,
                  ell=ell, ell_alpha=.3, pts=not ell)
    pt.plt.sca(ax)
Example #2
0
def show_hist_submaxima(hist_, edges=None, centers=None, maxima_thresh=.8, pnum=(1, 1, 1)):
    r"""
    For C++ to show data

    Args:
        hist_ (?):
        edges (None):
        centers (None):

    CommandLine:
        python -m vtool.histogram --test-show_hist_submaxima --show
        python -m pyhesaff._pyhesaff --test-test_rot_invar --show
        python -m vtool.histogram --test-show_hist_submaxima --dpath figures --save ~/latex/crall-candidacy-2015/figures/show_hist_submaxima.jpg

    Example:
        >>> # DISABLE_DOCTEST
        >>> import plottool as pt
        >>> from vtool.histogram import *  # NOQA
        >>> # build test data
        >>> hist_ = np.array(list(map(float, ut.get_argval('--hist', type_=list, default=[1, 4, 2, 5, 3, 3]))))
        >>> edges = np.array(list(map(float, ut.get_argval('--edges', type_=list, default=[0, 1, 2, 3, 4, 5, 6]))))
        >>> maxima_thresh = ut.get_argval('--maxima_thresh', type_=float, default=.8)
        >>> centers = None
        >>> # execute function
        >>> show_hist_submaxima(hist_, edges, centers, maxima_thresh)
        >>> pt.show_if_requested()
    """
    #print(repr(hist_))
    #print(repr(hist_.shape))
    #print(repr(edges))
    #print(repr(edges.shape))
    #ut.embed()
    import plottool as pt
    #ut.embed()
    if centers is None:
        centers = hist_edges_to_centers(edges)
    bin_colors = pt.get_orientation_color(centers)
    pt.figure(fnum=pt.next_fnum(), pnum=pnum)
    POLAR = False
    if POLAR:
        pt.df2.plt.subplot(*pnum, polar=True, axisbg='#000000')
    pt.draw_hist_subbin_maxima(hist_, centers, bin_colors=bin_colors, maxima_thresh=maxima_thresh)
    #pt.gca().set_rmax(hist_.max() * 1.1)
    #pt.gca().invert_yaxis()
    #pt.gca().invert_xaxis()
    pt.dark_background()
    #if ut.get_argflag('--legend'):
    #    pt.figure(fnum=pt.next_fnum())
    #    centers_ = np.append(centers, centers[0])
    #    r = np.ones(centers_.shape) * .2
    #    ax = pt.df2.plt.subplot(111, polar=True)
    #    pt.plots.colorline(centers_, r, cmap=pt.df2.plt.get_cmap('hsv'), linewidth=10)
    #    #ax.plot(centers_, r, 'm', color=bin_colors, linewidth=100)
    #    ax.set_rmax(.2)
    #    #ax.grid(True)
    #    #ax.set_title("Angle Colors", va='bottom')
    title = ut.get_argval('--title', default='')
    import plottool as pt
    pt.set_figtitle(title)
Example #3
0
def show_hist_submaxima(hist_,
                        edges=None,
                        centers=None,
                        maxima_thresh=.8,
                        pnum=(1, 1, 1)):
    r"""
    For C++ to show data

    Args:
        hist_ (?):
        edges (None):
        centers (None):

    CommandLine:
        python -m vtool.histogram --test-show_hist_submaxima --show
        python -m pyhesaff._pyhesaff --test-test_rot_invar --show
        python -m vtool.histogram --test-show_hist_submaxima --dpath figures --save ~/latex/crall-candidacy-2015/figures/show_hist_submaxima.jpg

    Example:
        >>> # DISABLE_DOCTEST
        >>> import plottool as pt
        >>> from vtool.histogram import *  # NOQA
        >>> # build test data
        >>> hist_ = np.array(list(map(float, ut.get_argval('--hist', type_=list, default=[1, 4, 2, 5, 3, 3]))))
        >>> edges = np.array(list(map(float, ut.get_argval('--edges', type_=list, default=[0, 1, 2, 3, 4, 5, 6]))))
        >>> maxima_thresh = ut.get_argval('--maxima_thresh', type_=float, default=.8)
        >>> centers = None
        >>> # execute function
        >>> show_hist_submaxima(hist_, edges, centers, maxima_thresh)
        >>> pt.show_if_requested()
    """
    #print(repr(hist_))
    #print(repr(hist_.shape))
    #print(repr(edges))
    #print(repr(edges.shape))
    #ut.embed()
    import plottool as pt
    #ut.embed()
    if centers is None:
        centers = hist_edges_to_centers(edges)
    bin_colors = pt.get_orientation_color(centers)
    pt.figure(fnum=pt.next_fnum(), pnum=pnum)
    POLAR = False
    if POLAR:
        pt.df2.plt.subplot(*pnum, polar=True, axisbg='#000000')
    pt.draw_hist_subbin_maxima(hist_,
                               centers,
                               bin_colors=bin_colors,
                               maxima_thresh=maxima_thresh)
    #pt.gca().set_rmax(hist_.max() * 1.1)
    #pt.gca().invert_yaxis()
    #pt.gca().invert_xaxis()
    pt.dark_background()
    #if ut.get_argflag('--legend'):
    #    pt.figure(fnum=pt.next_fnum())
    #    centers_ = np.append(centers, centers[0])
    #    r = np.ones(centers_.shape) * .2
    #    ax = pt.df2.plt.subplot(111, polar=True)
    #    pt.plots.colorline(centers_, r, cmap=pt.df2.plt.get_cmap('hsv'), linewidth=10)
    #    #ax.plot(centers_, r, 'm', color=bin_colors, linewidth=100)
    #    ax.set_rmax(.2)
    #    #ax.grid(True)
    #    #ax.set_title("Angle Colors", va='bottom')
    title = ut.get_argval('--title', default='')
    import plottool as pt
    pt.set_figtitle(title)
Example #4
0
    def show_graph(infr,
                   graph=None,
                   use_image=False,
                   update_attrs=True,
                   with_colorbar=False,
                   pnum=(1, 1, 1),
                   zoomable=True,
                   pickable=False,
                   **kwargs):
        r"""
        Args:
            infr (?):
            graph (None): (default = None)
            use_image (bool): (default = False)
            update_attrs (bool): (default = True)
            with_colorbar (bool): (default = False)
            pnum (tuple):  plot number(default = (1, 1, 1))
            zoomable (bool): (default = True)
            pickable (bool): (de = False)
            **kwargs: verbose, with_labels, fnum, layout, ax, pos, img_dict,
                      title, layoutkw, framewidth, modify_ax, as_directed,
                      hacknoedge, hacknode, node_labels, arrow_width, fontsize,
                      fontweight, fontname, fontfamilty, fontproperties

        CommandLine:
            python -m ibeis.algo.graph.mixin_viz GraphVisualization.show_graph --show

        Example:
            >>> # ENABLE_DOCTEST
            >>> from ibeis.algo.graph.mixin_viz import *  # NOQA
            >>> from ibeis.algo.graph import demo
            >>> import plottool as pt
            >>> infr = demo.demodata_infr(ccs=ut.estarmap(
            >>>    range, [(1, 6), (6, 10), (10, 13), (13, 15), (15, 16),
            >>>            (17, 20)]))
            >>> pnum_ = pt.make_pnum_nextgen(nRows=1, nCols=3)
            >>> infr.show_graph(show_cand=True, simple_labels=True, pickable=True, fnum=1, pnum=pnum_())
            >>> infr.add_feedback((1, 5), INCMP)
            >>> infr.add_feedback((14, 18), INCMP)
            >>> infr.refresh_candidate_edges()
            >>> infr.show_graph(show_cand=True, simple_labels=True, pickable=True, fnum=1, pnum=pnum_())
            >>> infr.add_feedback((17, 18), NEGTV)  # add inconsistency
            >>> infr.apply_nondynamic_update()
            >>> infr.show_graph(show_cand=True, simple_labels=True, pickable=True, fnum=1, pnum=pnum_())
            >>> ut.show_if_requested()
        """
        import plottool as pt
        if graph is None:
            graph = infr.graph
        # kwargs['fontsize'] = kwargs.get('fontsize', 8)
        with warnings.catch_warnings():
            warnings.simplefilter("ignore")
            # default_update_kw = ut.get_func_kwargs(infr.update_visual_attrs)
            # update_kw = ut.update_existing(default_update_kw, kwargs)
            # infr.update_visual_attrs(**update_kw)
            if update_attrs:
                infr.update_visual_attrs(graph=graph, **kwargs)
            verbose = kwargs.pop('verbose', infr.verbose)
            pt.show_nx(graph,
                       layout='custom',
                       as_directed=False,
                       modify_ax=False,
                       use_image=use_image,
                       pnum=pnum,
                       verbose=verbose,
                       **kwargs)
            if zoomable:
                pt.zoom_factory()
                pt.pan_factory(pt.gca())

        # if with_colorbar:
        #     # Draw a colorbar
        #     _normal_ticks = np.linspace(0, 1, num=11)
        #     _normal_scores = np.linspace(0, 1, num=500)
        #     _normal_colors = infr.get_colored_weights(_normal_scores)
        #     cb = pt.colorbar(_normal_scores, _normal_colors, lbl='weights',
        #                      ticklabels=_normal_ticks)

        #     # point to threshold location
        #     thresh = None
        #     if thresh is not None:
        #         xy = (1, thresh)
        #         xytext = (2.5, .3 if thresh < .5 else .7)
        #         cb.ax.annotate('threshold', xy=xy, xytext=xytext,
        #                        arrowprops=dict(
        #                            alpha=.5, fc="0.6",
        #                            connectionstyle="angle3,angleA=90,angleB=0"),)

        # infr.graph
        if graph.graph.get('dark_background', None):
            pt.dark_background(force=True)

        if pickable:
            fig = pt.gcf()
            fig.canvas.mpl_connect('pick_event', ut.partial(on_pick,
                                                            infr=infr))
Example #5
0
def show_coverage_grid(num_rows, num_cols, subbin_xy_arr,
                       neighbor_bin_centers, neighbor_bin_weights,
                       neighbor_bin_indices, fnum=None, pnum=None):
    """
    visualizes the voting scheme on the grid. (not a mask, and no max)
    """
    import plottool as pt
    import vtool as vt
    import matplotlib as mpl

    if fnum is None:
        fnum = pt.next_fnum()
    fig = pt.figure(fnum, pnum=pnum)
    ax = fig.gca()
    x_edge_indices = np.arange(num_cols)
    y_edge_indices = np.arange(num_rows)
    x_center_indices = vt.hist_edges_to_centers(x_edge_indices)
    y_center_indices = vt.hist_edges_to_centers(y_edge_indices)
    x_center_grid, y_center_grid = np.meshgrid(x_center_indices, y_center_indices)
    ax.set_xticks(x_edge_indices)
    ax.set_yticks(y_edge_indices)
    # Plot keypoint loc
    ax.scatter(subbin_xy_arr[0], subbin_xy_arr[1], marker='o')
    # Plot Weighted Lines to Subbin
    pt_colors = pt.distinct_colors(len(subbin_xy_arr.T))
    segment_list = []
    color_list = []
    for subbin_centers, subbin_weights in zip(neighbor_bin_centers,
                                              neighbor_bin_weights):
        for pt_xys, center_xys, weight, color in zip(subbin_xy_arr.T, subbin_centers,
                                                     subbin_weights, pt_colors):
            # Adjsut weight to alpha for easier visualization
            alpha = weight
            INCRESE_ALPHA_VISIBILITY = True
            if INCRESE_ALPHA_VISIBILITY:
                min_viz_alpha = .05
                alpha = alpha * (1.0 - min_viz_alpha) + min_viz_alpha
                alpha **= 1.0
            #pt.plots.colorline(
            segment = np.vstack((pt_xys, center_xys))
            segment_list.append(segment)
            # Alpha becomes part of the colors
            color_list.append(list(color) + [alpha])
            # DO NOT USE PLOT VERY SLOW
            #ax.plot(*segment.T, color=color, alpha=alpha, lw=3)
    ax = pt.gca()
    # Plot all segments in single  line collection for speed
    # solid | dashed | dashdot | dotted
    lc = mpl.collections.LineCollection(segment_list, colors=color_list, linewidth=3, linestyles='solid')
    ax.add_collection(lc)
    # Plot Grid Center
    num_cells = num_cols * num_rows
    grid_alpha = min(.4, max(1 - (num_cells / 500), .1))
    grid_color = [.6, .6, .6, grid_alpha]
    #print(grid_color)
    # Plot grid cetner
    ax.scatter(x_center_grid, y_center_grid, marker='.', color=grid_color,
               s=grid_alpha)

    ax.set_xlim(0, num_cols - 1)
    ax.set_ylim(0, num_rows - 1)
    #-----
    pt.dark_background()
    ax.grid(True, color=[.3, .3, .3])
    ax.set_xticklabels([])
    ax.set_yticklabels([])
Example #6
0
def hackshow_names(ibs, aid_list, fnum=None):
    r"""
    Args:
        ibs (IBEISController):  ibeis controller object
        aid_list (list):

    CommandLine:
        python -m ibeis.other.dbinfo --exec-hackshow_names --show
        python -m ibeis.other.dbinfo --exec-hackshow_names --show --db PZ_Master1

    Example:
        >>> # DISABLE_DOCTEST
        >>> from ibeis.other.dbinfo import *  # NOQA
        >>> import ibeis
        >>> ibs = ibeis.opendb(defaultdb='PZ_MTEST')
        >>> aid_list = ibs.get_valid_aids()
        >>> result = hackshow_names(ibs, aid_list)
        >>> print(result)
        >>> ut.show_if_requested()
    """
    import plottool as pt
    import vtool as vt
    grouped_aids, nid_list = ibs.group_annots_by_name(aid_list)
    grouped_aids = [aids for aids in grouped_aids if len(aids) > 1]
    unixtimes_list = ibs.unflat_map(ibs.get_annot_image_unixtimes_asfloat, grouped_aids)
    yaws_list = ibs.unflat_map(ibs.get_annot_yaws, grouped_aids)
    #markers_list = [[(1, 2, yaw * 360 / (np.pi * 2)) for yaw in yaws] for yaws in yaws_list]

    unixtime_list = ut.flatten(unixtimes_list)
    timemax = np.nanmax(unixtime_list)
    timemin = np.nanmin(unixtime_list)
    timerange = timemax - timemin
    unixtimes_list = [((unixtimes[:] - timemin) / timerange) for unixtimes in unixtimes_list]
    for unixtimes in unixtimes_list:
        num_nan = sum(np.isnan(unixtimes))
        unixtimes[np.isnan(unixtimes)] = np.linspace(-1, -.5, num_nan)
    #ydata_list = [np.arange(len(aids)) for aids in grouped_aids]
    sortx_list = vt.argsort_groups(unixtimes_list, reverse=False)
    #markers_list = ut.list_ziptake(markers_list, sortx_list)
    yaws_list = ut.list_ziptake(yaws_list, sortx_list)
    ydatas_list = vt.ziptake(unixtimes_list, sortx_list)
    #ydatas_list = sortx_list
    #ydatas_list = vt.argsort_groups(unixtimes_list, reverse=False)

    # Sort by num members
    #ydatas_list = ut.take(ydatas_list, np.argsort(list(map(len, ydatas_list))))
    xdatas_list = [np.zeros(len(ydatas)) + count for count, ydatas in enumerate(ydatas_list)]
    #markers = ut.flatten(markers_list)
    #yaws = np.array(ut.flatten(yaws_list))
    y_data = np.array(ut.flatten(ydatas_list))
    x_data = np.array(ut.flatten(xdatas_list))
    fnum = pt.ensure_fnum(fnum)
    pt.figure(fnum=fnum)
    ax = pt.gca()

    #unique_yaws, groupxs = vt.group_indices(yaws)

    ax.scatter(x_data, y_data, color=[1, 0, 0], s=1, marker='.')
    #pt.draw_stems(x_data, y_data, marker=markers, setlims=True, linestyle='')
    pt.dark_background()
    ax = pt.gca()
    ax.set_xlim(min(x_data) - .1, max(x_data) + .1)
    ax.set_ylim(min(y_data) - .1, max(y_data) + .1)
Example #7
0
def in_depth_ellipse(kp):
    """
    Makes sure that I understand how the ellipse is created form a keypoint
    representation. Walks through the steps I took in coming to an
    understanding.

    CommandLine:
        python -m pyhesaff.tests.test_ellipse --test-in_depth_ellipse --show --num-samples=12

    Example:
        >>> # SCRIPT
        >>> from pyhesaff.tests.test_ellipse import *  # NOQA
        >>> import pyhesaff.tests.pyhestest as pyhestest
        >>> test_data = pyhestest.load_test_data(short=True)
        >>> kpts = test_data['kpts']
        >>> kp = kpts[0]
        >>> #kp = np.array([0, 0, 10, 10, 10, 0])
        >>> test_locals = in_depth_ellipse(kp)
        >>> ut.quit_if_noshow()
        >>> ut.show_if_requested()
    """
    import plottool as pt
    #nSamples = 12
    nSamples = ut.get_argval('--num-samples', type_=int, default=12)
    kp = np.array(kp, dtype=np.float64)
    #-----------------------
    # SETUP
    #-----------------------
    np.set_printoptions(precision=3)
    #pt.reset()
    pt.figure(9003, docla=True, doclf=True)
    ax = pt.gca()
    ax.invert_yaxis()

    def _plotpts(data, px, color=pt.BLUE, label='', marker='.', **kwargs):
        #pt.figure(9003, docla=True, pnum=(1, 1, px))
        pt.plot2(data.T[0],
                 data.T[1],
                 marker,
                 '',
                 color=color,
                 label=label,
                 **kwargs)
        #pt.update()

    def _plotarrow(x, y, dx, dy, color=pt.BLUE, label=''):
        ax = pt.gca()
        arrowargs = dict(head_width=.5, length_includes_head=True, label=label)
        arrow = mpl.patches.FancyArrow(x, y, dx, dy, **arrowargs)
        arrow.set_edgecolor(color)
        arrow.set_facecolor(color)
        ax.add_patch(arrow)
        #pt.update()

    #-----------------------
    # INPUT
    #-----------------------
    print('kp = %s' % ut.repr2(kp, precision=3))
    print('--------------------------------')
    print('Let V = Perdoch.A')
    print('Let Z = Perdoch.E')
    print('Let invV = Perdoch.invA')
    print('--------------------------------')
    print('Input from Perdoch\'s detector: ')

    # We are given the keypoint in invA format
    if len(kp) == 5:
        (ix, iy, iv11, iv21, iv22) = kp
        iv12 = 0
    elif len(kp) == 6:
        (ix, iy, iv11, iv21, iv22, ori) = kp
        iv12 = 0
    invV = np.array([[iv11, iv12, ix], [iv21, iv22, iy], [0, 0, 1]])
    V = np.linalg.inv(invV)
    Z = (V.T).dot(V)

    import vtool as vt
    V_2x2 = V[0:2, 0:2]
    Z_2x2 = Z[0:2, 0:2]
    V_2x2_ = vt.decompose_Z_to_V_2x2(Z_2x2)
    assert np.all(np.isclose(V_2x2, V_2x2_))

    #C = np.linalg.cholesky(Z)
    #np.isclose(C.dot(C.T), Z)
    #Z

    print('invV is a transform from points on a unit-circle to the ellipse')
    ut.horiz_print('invV = ', invV)
    print('--------------------------------')
    print('V is a transformation from points on the ellipse to a unit circle')
    ut.horiz_print('V = ', V)
    print('--------------------------------')
    print('An ellipse is a special case of a conic. For any ellipse:')
    print(
        'Points on the ellipse satisfy (x_ - x_0).T.dot(Z).dot(x_ - x_0) = 1')
    print('where Z = (V.T).dot(V)')
    ut.horiz_print('Z = ', Z)

    # Define points on a unit circle
    theta_list = np.linspace(0, TAU, nSamples)
    cicrle_pts = np.array([(np.cos(t_), np.sin(t_), 1) for t_ in theta_list])

    # Transform those points to the ellipse using invV
    ellipse_pts1 = invV.dot(cicrle_pts.T).T

    #Lets check our assertion: (x_ - x_0).T.dot(Z).dot(x_ - x_0) == 1
    x_0 = np.array([ix, iy, 1])
    checks = [(x_ - x_0).T.dot(Z).dot(x_ - x_0) for x_ in ellipse_pts1]
    try:
        # HELP: The phase is off here. in 3x3 version I'm not sure why
        #assert all([almost_eq(1, check) for check in checks1])
        is_almost_eq_pos1 = [ut.almost_eq(1, check) for check in checks]
        is_almost_eq_neg1 = [ut.almost_eq(-1, check) for check in checks]
        assert all(is_almost_eq_pos1)
    except AssertionError as ex:
        print('circle pts = %r ' % cicrle_pts)
        print(ex)
        print(checks)
        print([ut.almost_eq(-1, check, 1E-9) for check in checks])
        raise
    else:
        #assert all([abs(1 - check) < 1E-11 for check in checks2])
        print('... all of our plotted points satisfy this')

    #=======================
    # THE CONIC SECTION
    #=======================
    # All of this was from the Perdoch paper, now lets move into conic sections
    # We will use the notation from wikipedia
    # References:
    #     http://en.wikipedia.org/wiki/Conic_section
    #     http://en.wikipedia.org/wiki/Matrix_representation_of_conic_sections

    #-----------------------
    # MATRIX REPRESENTATION
    #-----------------------
    # The matrix representation of a conic is:
    #(A,  B2, B2_, C) = Z.flatten()
    #(D, E, F) = (0, 0, 1)
    (A, B2, D2, B2_, C, E2, D2_, E2_, F) = Z.flatten()
    B = B2 * 2
    D = D2 * 2
    E = E2 * 2
    assert B2 == B2_, 'matrix should by symmetric'
    assert D2 == D2_, 'matrix should by symmetric'
    assert E2 == E2_, 'matrix should by symmetric'
    print('--------------------------------')
    print('Now, using wikipedia\' matrix representation of a conic.')
    con = np.array((('    A', 'B / 2', 'D / 2'), ('B / 2', '    C', 'E / 2'),
                    ('D / 2', 'E / 2', '    F')))
    ut.horiz_print('A matrix A_Q = ', con)

    # A_Q is our conic section (aka ellipse matrix)
    A_Q = np.array(((A, B / 2, D / 2), (B / 2, C, E / 2), (D / 2, E / 2, F)))

    ut.horiz_print('A_Q = ', A_Q)

    #-----------------------
    # DEGENERATE CONICS
    # References:
    #    http://individual.utoronto.ca/somody/quiz.html
    print('----------------------------------')
    print('As long as det(A_Q) != it is not degenerate.')
    print('If the conic is not degenerate, we can use the 2x2 minor: A_33')
    print('det(A_Q) = %s' % str(np.linalg.det(A_Q)))
    assert np.linalg.det(A_Q) != 0, 'degenerate conic'
    A_33 = np.array(((A, B / 2), (B / 2, C)))
    ut.horiz_print('A_33 = ', A_33)

    #-----------------------
    # CONIC CLASSIFICATION
    #-----------------------
    print('----------------------------------')
    print('The determinant of the minor classifies the type of conic it is')
    print('(det == 0): parabola, (det < 0): hyperbola, (det > 0): ellipse')
    print('det(A_33) = %s' % str(np.linalg.det(A_33)))
    assert np.linalg.det(A_33) > 0, 'conic is not an ellipse'
    print('... this is indeed an ellipse')

    #-----------------------
    # CONIC CENTER
    #-----------------------
    print('----------------------------------')
    print('the centers of the ellipse are obtained by: ')
    print('x_center = (B * E - (2 * C * D)) / (4 * A * C - B ** 2)')
    print('y_center = (D * B - (2 * A * E)) / (4 * A * C - B ** 2)')
    # Centers are obtained by solving for where the gradient of the quadratic
    # becomes 0. Without going through the derivation the calculation is...
    # These should be 0, 0 if we are at the origin, or our original x, y
    # coordinate specified by the keypoints. I'm doing the calculation just for
    # shits and giggles
    x_center = (B * E - (2 * C * D)) / (4 * A * C - B**2)
    y_center = (D * B - (2 * A * E)) / (4 * A * C - B**2)
    ut.horiz_print('x_center = ', x_center)
    ut.horiz_print('y_center = ', y_center)

    #-----------------------
    # MAJOR AND MINOR AXES
    #-----------------------
    # Now we are going to determine the major and minor axis
    # of this beast. It just the center augmented by the eigenvecs
    print('----------------------------------')
    # Plot ellipse axis
    # !HELP! I DO NOT KNOW WHY I HAVE TO DIVIDE, SQUARE ROOT, AND NEGATE!!!
    (evals, evecs) = np.linalg.eig(A_33)
    l1, l2 = evals
    # The major and minor axis lengths
    b = 1 / np.sqrt(l1)
    a = 1 / np.sqrt(l2)
    v1, v2 = evecs
    # Find the transformation to align the axis
    nminor = v1
    nmajor = v2
    dx1, dy1 = (v1 * b)
    dx2, dy2 = (v2 * a)
    minor = np.array([dx1, -dy1])
    major = np.array([dx2, -dy2])
    x_axis = np.array([[1], [0]])
    cosang = (x_axis.T.dot(nmajor)).T
    # Rotation angle
    theta = np.arccos(cosang)
    print('a = ' + str(a))
    print('b = ' + str(b))
    print('theta = ' + str(theta[0] / TAU) + ' * 2pi')
    # The warped eigenvects should have the same magintude
    # As the axis lengths
    assert ut.almost_eq(a, major.dot(ltool.rotation_mat2x2(theta))[0])
    assert ut.almost_eq(b, minor.dot(ltool.rotation_mat2x2(theta))[1])
    try:
        # HACK
        if len(theta) == 1:
            theta = theta[0]
    except Exception:
        pass

    #-----------------------
    # ECCENTRICITY
    #-----------------------
    print('----------------------------------')
    print('The eccentricity is determined by:')
    print('')
    print('            (2 * np.sqrt((A - C) ** 2 + B ** 2))     ')
    print('ecc = -----------------------------------------------')
    print('      (nu * (A + C) + np.sqrt((A - C) ** 2 + B ** 2))')
    print('')
    print('(nu is always 1 for ellipses)')
    nu = 1
    ecc_numer = (2 * np.sqrt((A - C)**2 + B**2))
    ecc_denom = (nu * (A + C) + np.sqrt((A - C)**2 + B**2))
    ecc = np.sqrt(ecc_numer / ecc_denom)
    print('ecc = ' + str(ecc))

    # Eccentricity is a little easier in axis aligned coordinates
    # Make sure they aggree
    ecc2 = np.sqrt(1 - (b**2) / (a**2))
    assert ut.almost_eq(ecc, ecc2)

    #-----------------------
    # APPROXIMATE UNIFORM SAMPLING
    #-----------------------
    # We are given the keypoint in invA format
    print('----------------------------------')
    print('Approximate uniform points an inscribed polygon bondary')

    #def next_xy(x, y, d):
    #    # References:
    #    # http://gamedev.stackexchange.com/questions/1692/what-is-a-simple-algorithm-for-calculating-evenly-distributed-points-on-an-ellip
    #    num = (b ** 2) * (x ** 2)
    #    den = ((a ** 2) * ((a ** 2) - (x ** 2)))
    #    dxdenom = np.sqrt(1 + (num / den))
    #    deltax = d / dxdenom
    #    x_ = x + deltax
    #    y_ = b * np.sqrt(1 - (x_ ** 2) / (a ** 2))
    #    return x_, y_

    def xy_fn(t):
        return np.array((a * np.cos(t), b * np.sin(t))).T

    #nSamples = 16
    #(ix, iy, iv11, iv21, iv22), iv12 = kp, 0
    #invV = np.array([[iv11, iv12, ix],
    #                 [iv21, iv22, iy],
    #                 [   0,    0,  1]])
    #theta_list = np.linspace(0, TAU, nSamples)
    #cicrle_pts = np.array([(np.cos(t_), np.sin(t_), 1) for t_ in theta_list])
    uneven_points = invV.dot(cicrle_pts.T).T[:, 0:2]

    #uneven_points2 = xy_fn(theta_list)

    def circular_distance(arr):
        dist_most_ = ((arr[0:-1] - arr[1:])**2).sum(1)
        dist_end_ = ((arr[-1] - arr[0])**2).sum()
        return np.sqrt(np.hstack((dist_most_, dist_end_)))

    # Calculate the distance from each point on the ellipse to the next
    dists = circular_distance(uneven_points)
    total_dist = dists.sum()
    # Get an even step size
    multiplier = 1
    step_size = total_dist / (nSamples * multiplier)
    # Walk along edge
    num_steps_list = []
    offset_list = []
    dist_walked = 0
    total_dist = step_size
    for count in range(len(dists)):
        segment_len = dists[count]
        # Find where your starting location is
        offset_list.append(total_dist - dist_walked)
        # How far can you possibly go?
        total_dist += segment_len
        # How many steps can you take?
        num_steps = int((total_dist - dist_walked) // step_size)
        num_steps_list.append(num_steps)
        # Log how much further youve gotten
        dist_walked += (num_steps * step_size)
    #print('step_size = %r' % step_size)
    #print(np.vstack((num_steps_list, dists, offset_list)).T)

    # store the percent location at each line segment where
    # the cut will be made
    cut_list = []
    for num, dist, offset in zip(num_steps_list, dists, offset_list):
        if num == 0:
            cut_list.append([])
            continue
        offset1 = (step_size - offset) / dist
        offset2 = ((num * step_size) - offset) / dist
        cut_locs = (np.linspace(offset1, offset2, num, endpoint=True))
        cut_list.append(cut_locs)
        #print(cut_locs)

    # Cut the segments into new better segments
    approx_pts = []
    nPts = len(uneven_points)
    for count, cut_locs in enumerate(cut_list):
        for loc in cut_locs:
            pt1 = uneven_points[count]
            pt2 = uneven_points[(count + 1) % nPts]
            # Linearly interpolate between points
            new_loc = ((1 - loc) * pt1) + ((loc) * pt2)
            approx_pts.append(new_loc)
    approx_pts = np.array(approx_pts)

    # Warp approx_pts to the unit circle
    print('----------------------------------')
    print('For each aproximate point, find the closet point on the ellipse')
    #new_unit = V.dot(approx_pts.T).T
    ones_ = np.ones(len(approx_pts))
    new_hlocs = np.vstack((approx_pts.T, ones_))
    new_unit = V.dot(new_hlocs).T
    # normalize new_unit
    new_mag = np.sqrt((new_unit**2).sum(1))
    new_unorm_unit = new_unit / np.vstack([new_mag] * 3).T
    new_norm_unit = new_unorm_unit / np.vstack([new_unorm_unit[:, 2]] * 3).T
    # Get angle (might not be necessary)
    x_axis = np.array([1, 0, 0])
    arccos_list = x_axis.dot(new_norm_unit.T)
    uniform_theta_list = np.arccos(arccos_list)
    # Maybe this?
    uniform_theta_list = np.arctan2(new_norm_unit[:, 1], new_norm_unit[:, 0])
    #
    unevn_cicrle_pts = np.array([(np.cos(t_), np.sin(t_), 1)
                                 for t_ in uniform_theta_list])
    # This is the output. Approximately uniform points sampled along an ellipse
    uniform_ell_pts = invV.dot(unevn_cicrle_pts.T).T
    #uniform_ell_pts = invV.dot(new_norm_unit.T).T

    _plotpts(approx_pts, 0, pt.YELLOW, label='approx points', marker='o-')
    _plotpts(uniform_ell_pts, 0, pt.RED, label='uniform points', marker='o-')

    # Desired number of points
    #ecc = np.sqrt(1 - (b ** 2) / (a ** 2))
    # Total arclength
    #total_arclen = ellipeinc(TAU, ecc)
    #firstquad_arclen = total_arclen / 4
    # Desired arclength between points
    #d = firstquad_arclen / nSamples
    # Initial point
    #x, y = xy_fn(.001)
    #uniform_points = []
    #for count in range(nSamples):
    #    if np.isnan(x_) or np.isnan(y_):
    #        print('nan on count=%r' % count)
    #        break
    #    uniform_points.append((x_, y_))
    # The angle between the major axis and our x axis is:
    #-----------------------
    # DRAWING
    #-----------------------
    print('----------------------------------')
    # Draw the keypoint using the tried and true pt
    # Other things should subsiquently align
    #pt.draw_kpts2(np.array([kp]), ell_linewidth=4,
    #               ell_color=pt.DEEP_PINK, ell_alpha=1, arrow=True, rect=True)

    # Plot ellipse points
    _plotpts(ellipse_pts1,
             0,
             pt.LIGHT_BLUE,
             label='invV.dot(cicrle_pts.T).T',
             marker='o-')

    _plotarrow(x_center,
               y_center,
               dx1,
               -dy1,
               color=pt.GRAY,
               label='minor axis')
    _plotarrow(x_center,
               y_center,
               dx2,
               -dy2,
               color=pt.GRAY,
               label='major axis')

    # Rotate the ellipse so it is axis aligned and plot that
    rot = ltool.rotation_around_mat3x3(theta, ix, iy)
    ellipse_pts3 = rot.dot(ellipse_pts1.T).T
    #!_plotpts(ellipse_pts3, 0, pt.GREEN, label='axis aligned points')

    # Plot ellipse orientation
    ortho_basis = np.eye(3)[:, 0:2]
    orient_axis = invV.dot(ortho_basis)
    print(orient_axis)
    _dx1, _dx2, _dy1, _dy2, _1, _2 = orient_axis.flatten()
    #!_plotarrow(x_center, y_center, _dx1, _dy1, color=pt.BLUE, label='ellipse rotation')
    #!_plotarrow(x_center, y_center, _dx2, _dy2, color=pt.BLUE)

    #pt.plt.gca().set_xlim(400, 600)
    #pt.plt.gca().set_ylim(300, 500)

    xmin, ymin = ellipse_pts1.min(0)[0:2] - 1
    xmax, ymax = ellipse_pts1.max(0)[0:2] + 1
    pt.plt.gca().set_xlim(xmin, xmax)
    pt.plt.gca().set_ylim(ymin, ymax)
    pt.legend()
    pt.dark_background(doubleit=3)
    pt.gca().invert_yaxis()

    # Hack in another view
    # It seems like the even points are not actually that even.
    # there must be a bug

    pt.figure(fnum=9003 + 1, docla=True, doclf=True, pnum=(1, 3, 1))
    _plotpts(ellipse_pts1,
             0,
             pt.LIGHT_BLUE,
             label='invV.dot(cicrle_pts.T).T',
             marker='o-',
             title='even')
    pt.plt.gca().set_xlim(xmin, xmax)
    pt.plt.gca().set_ylim(ymin, ymax)
    pt.dark_background(doubleit=3)
    pt.gca().invert_yaxis()
    pt.figure(fnum=9003 + 1, pnum=(1, 3, 2))

    _plotpts(approx_pts,
             0,
             pt.YELLOW,
             label='approx points',
             marker='o-',
             title='approx')
    pt.plt.gca().set_xlim(xmin, xmax)
    pt.plt.gca().set_ylim(ymin, ymax)
    pt.dark_background(doubleit=3)
    pt.gca().invert_yaxis()

    pt.figure(fnum=9003 + 1, pnum=(1, 3, 3))
    _plotpts(uniform_ell_pts,
             0,
             pt.RED,
             label='uniform points',
             marker='o-',
             title='uniform')
    pt.plt.gca().set_xlim(xmin, xmax)
    pt.plt.gca().set_ylim(ymin, ymax)
    pt.dark_background(doubleit=3)
    pt.gca().invert_yaxis()

    return locals()