def plot_fewer_markers(
x, ax, marker_npnt, line_npnt,
style, **kwargs
):
"""Same line, different number of markers.
@param ax: axes object handle
@param x: abscissa vector
@param marker_npnt: # markers
@param line_npnt: # points used for line
@param style: line and marker style
= plot style string, e.g., 'ro--'
| cell array {graph_color, line_style,
marker_style}, e.g.,
{'b', '--', 'o'}, or {[0,0,1], '--', 'o'}
note: the 2nd option allows for
RGB color specification.
"""
# input
if nargin < 3:
style = ''
# defaults by parse_plot_style
if nargin < 4:
marker_npnt = 10
if nargin < 5:
line_npnt = 100
# cell with RGB color specs ?
if iscell(style):
graph_color = style[0]
line_style = style[1]
marker_style = style[2]
else:
# or string style ?
graph_color, marker_style, \
line_style = parse_plot_style(style) # nargout=3
#
# plot
c = takehold(ax, 'on')
# marker of 1st pnt for legend to get correct style
plot(ax, x[:, 0], 'Color', graph_color,
'LineStyle', line_style, 'Marker', marker_style)
# line
plot_subsample(ax, x, line_npnt, 'Color',
graph_color, 'LineStyle',
line_style, 'Marker', 'none',
'HandleVisibility', 'off')
# markers
plot_subsample(ax, x, marker_npnt, 'Color',
graph_color, 'LineStyle', 'none',
'Marker', marker_style,
'HandleVisibility', 'off')
restorehold(ax, c)
def plot_subsample_arclength(x, n=100, ax, **kwargs):
"""Subsample wrt arclength metric & plot curve.
@param ax: axes object handle where to plot
@param x: point abscissas (as passed to plot)
@param y: point ordinates (as passed to plot)
@param n: number of points to keep > 0
@param kwargs: arguments passed to plot
"""
if not isscalar(n):
error('n: # of sample, must be scalar.')
# plot
x = subsample(x, n, 2, 'arclength')
plot(ax, x, varargin[:])
def test_plot_subsample_arclength():
"""Visually compare plot, plot_subsample, plot_subsample_arclength.
"""
from math import exp
cls
t = 2 *np.pi /exp(range(10) )
x = np.array([cos(t), sin(t)]).reshape(1, -1)
fig = figure
ax = newax(fig, np.array([1, 3]).reshape(1, -1))
mhold(ax, 'on')
plot(ax, x, 'ro-')
plot_subsample(ax(2), x, 100, 'm--*')
plot_subsample_arclength(ax(3), x, 100, 'bs')
supertitle(fig, 'Comparison: plot subsampling methods')
stitle = ['plot', 'plot\\_subsample', 'plot\\_subsample\\_arclength']
plotidy2(ax, '$x$', '$y$', stitle)
axis(ax, 'image')
def example_plot_subsample():
"""example using plot_subsample, plot2_subsample
"""
npnt = 1000
n_sample = 10
t = linspace(0, 4 * pi, npnt)
fig = figure
ax = newax(fig, np.array([1, 2]).reshape(1, -1))
mhold(ax, 'on')
"""2d example"""
x = t
y = sin(t)
plt.plot(ax(1), x, y, 'b-')
plot2_subsample(ax(1), x, y, n_sample, 'r--o')
plotidy2(ax(1))
"""3d example"""
x = np.array([t, cos(t), sin(t)]).reshape(1, -1)
plot(ax(2), x, 'b-')
plot_subsample(ax(2), x, n_sample, 'r--o')
plotidy(ax(2))
axis(ax(2), 'equal')
