我正在尝试创建一个散点图，其中每个点的颜色基于 y 维度的值，每个点的工具提示基于 x 轴的值。我需要为鼠标悬停事件的每个点创建工具提示，我能够实现这一点。我想将此图保存到带有事件的 svg 文件中，以便可以在浏览器中使用工具提示查看该 svg 文件。
当我尝试保存时出现以下错误，
Traceback (most recent call last):
File "./altered_tooltip.py", line 160, in <module>
example.plot()
File "./altered_tooltip.py", line 70, in plot
pl.savefig(f, format="svg")
File "/usr/lib/pymodules/python2.7/matplotlib/pyplot.py", line 561, in savefig
return fig.savefig(*args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 1421, in savefig
self.canvas.print_figure(*args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/backend_bases.py", line 2220, in print_figure
**kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/backend_bases.py", line 1978, in print_svg
return svg.print_svg(*args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_svg.py", line 1157, in print_svg
return self._print_svg(filename, svgwriter, fh_to_close, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_svg.py", line 1185, in _print_svg
self.figure.draw(renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 1034, in draw
func(*args)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 2086, in draw
a.draw(renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/collections.py", line 718, in draw
return Collection.draw(self, renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/collections.py", line 250, in draw
renderer.open_group(self.__class__.__name__, self.get_gid())
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_svg.py", line 516, in open_group
self.writer.start('g', id=gid)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_svg.py", line 141, in start
v = escape_attrib(v)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_svg.py", line 80, in escape_attrib
s = s.replace(u"&", u"&")
AttributeError: 'list' object has no attribute 'replace'
我正在运行的代码是
from numpy import *
import pylab as pl
import matplotlib.colors as mcolors
import xml.etree.ElementTree as ET
from StringIO import StringIO
ET.register_namespace("","http://www.w3.org/2000/svg")
class wxToolTipExample(object):
def __init__(self, plot_data):
self.figure = pl.figure()
self.axis = pl.axes()
self.ax = self.figure.add_subplot(111)
self.tooltip.SetTip() calls
self.dataX = plot_data[:,0]
self.dataY = plot_data[:,1]
self.annotes = []
self.pathCol = None #to hold the scatter object
def plot(self):
for idx in arange(self.dataX.size):
# create a tuple of co-ordinates
tup = (self.dataX[idx], self.dataY[idx])
# create annotation with tooltip
annotation = self.axis.annotate("Column %s" % int(self.dataX[idx]),
xy=tup, xycoords='data',
xytext=(+10, +30), textcoords='offset points',
#horizontalalignment="right",
arrowprops=dict(arrowstyle="->",
connectionstyle="arc3,rad=0.2"),
#bbox=dict(boxstyle="round", facecolor="w",
# edgecolor="0.0", alpha=0.0)
)
# by default, disable the annotation visibility
annotation.set_visible(False)
# append the annotation object and co-ords tuple to the list
self.annotes.append([tup, annotation])
self.figure.canvas.mpl_connect('motion_notify_event', self._onMotion)
c_map = self.WGrYR()
self.pathCol = self.axis.scatter(self.dataX, self.dataY, c=self.dataY, marker='s', s=40, cmap=c_map)
# Set id for the annotations
for i, t in enumerate(self.axis.texts):
t.set_gid('tooltip_%d'%i)
# Set id for the points on the scatter plot
points = ['point_{0}'.format(ii) for ii in arange(1, self.dataX.size+1)]
self.pathCol.set_gid(points)
f = StringIO()
#pl.show()
pl.savefig(f, format="svg")
"""
# Create XML tree from the SVG file.
tree, xmlid = ET.XMLID(f.getvalue())
tree.set('onload', 'init(evt)')
# Hide the tooltips
for i, t in enumerate(self.axis.texts):
ele = xmlid['tooltip_%d'%i]
ele.set('visibility','hidden')
# assign mouseover and mouseout events
for p in points:
ele = xmlid[p]
ele.set('onmouseover', "ShowTooltip(this)")
ele.set('onmouseout', "HideTooltip(this)")
script = self.getSvgScript()
# Insert the script at the top of the file and save it.
tree.insert(0, ET.XML(script))
ET.ElementTree(tree).write('svg_tooltip.svg')
"""
def getSvgScript(self):
return """
<script type="text/ecmascript">
<![CDATA[
function init(evt) {
if ( window.svgDocument == null ) {
svgDocument = evt.target.ownerDocument;
}
}
function ShowTooltip(obj) {
var cur = obj.id.slice(-1);
var tip = svgDocument.getElementById('tooltip_' + cur);
tip.setAttribute('visibility',"visible")
}
function HideTooltip(obj) {
var cur = obj.id.slice(-1);
var tip = svgDocument.getElementById('tooltip_' + cur);
tip.setAttribute('visibility',"hidden")
}
]]>
</script>
"""
def _onMotion(self, event):
visibility_changed = False
for point, annotation in self.annotes:
if event.xdata != None and event.ydata != None: # mouse is inside the axes
should_be_visible = abs(point[0]-event.xdata) < 0.2 and abs(point[1]-event.ydata) < 0.05
if should_be_visible != annotation.get_visible():
visibility_changed = True
annotation.set_visible(should_be_visible)
if visibility_changed:
pl.draw()
def WGrYR(self):
c = mcolors.ColorConverter().to_rgb
seq = [c('white'), c('grey'), 0.33, c('grey'), c('yellow'), 0.66, c('yellow'), c('red')]
seq = [(None,) * 3, 0.0] + list(seq) + [1.0, (None,) * 3]
cdict = {'red': [], 'green': [], 'blue': []}
for i, item in enumerate(seq):
if isinstance(item, float):
r1, g1, b1 = seq[i - 1]
r2, g2, b2 = seq[i + 1]
cdict['red'].append([item, r1, r2])
cdict['green'].append([item, g1, g2])
cdict['blue'].append([item, b1, b2])
#print cdict
return mcolors.LinearSegmentedColormap('Custom_WGrYR', cdict)
ET.register_namespace("","http://www.w3.org/2000/svg")
# test column heat for nodes
n_cols = 5
plot_data = zeros((n_cols,2))
# generate column numbers and random heat values to test
plot_data[:,0] = asarray(arange(1, n_cols+1))#.reshape(n_cols,1)
plot_data[:,1] = random.rand(n_cols,1).reshape(n_cols,)
example = wxToolTipExample(plot_data)
example.plot()
我哪里出错了？
最佳答案
您的代码看起来像是一项正在进行的工作，尚未完全清理。 (我必须注释掉 self.tooltip.SetTip() calls 才能让它运行。)但以下是您立即出现问题的原因(您注意到的异常)以及我是如何发现它的:
在我的机器上，我编辑了 backend_svg.py 函数 start()添加print(extra)然后我运行你的代码。由于你的台词:
points = ['point_{0}'.format(ii) for ii in arange(1, self.dataX.size+1)]
self.pathCol.set_gid(points)
matplotlib 后端尝试创建 SVG <g> ID 为 ['point_1', 'point_2', 'point_3', 'point_4', 'point_5'] 的节点。这是一个列表，而不是一个有效的字符串，所以 s.replace()失败。
最终您必须更改代码，以便 set_gid()只接收字符串参数。最简单的方法是将上面的两行更改为:
self.pathCol.set_gid('point_1')
但是您不会获得生成的 SVG 中各个点的 ID。您还可以删除 self.pathCol.set_gid线(pathCol 它将被渲染为 SVG <g id="PathCollection_1"> 并且点也没有 ID)。
将 SVG ID 分配给 pathCollection 中包含的各个点/顶点似乎并不简单。如果您需要这样做，您可能需要想出另一种方法来绘制它们 - 如果我正确理解问题，您需要绘制单个点而不是路径。
关于Python matplotlib : Error while saving scatter plot in svg format，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28626567/