plot画图时可以设定线条参数。包括：颜色、线型、标记风格。

1)控制颜色

颜色之间的对应关系为

b---blue   c---cyan  g---green    k----black

m---magenta r---red  w---white    y----yellow

有三种表示颜色的方式:

a:用全名  b:16进制如：#FF00FF  c：RGB或RGBA元组(1,0,1,1) d：灰度强度如：‘0.7’

2)控制线型

符号和线型之间的对应关系

-      实线

--     短线

-.     短点相间线

：     虚点线

>>>import matplotlib >>>from pylab import * >>>help(plot) Help on function plot in module matplotlib.pyplot: plot(*args, **kwargs)     Plot lines and/or markers to the     :class:`~matplotlib.axes.Axes`.  *args* is a variable length     argument, allowing for multiple *x*, *y* pairs with an     optional format string.  For example, each of the following is     legal::              plot(x, y)         # plot x and y using default line style and color         plot(x, y, 'bo')   # plot x and y using blue circle markers         plot(y)            # plot y using x as index array 0..N-1         plot(y, 'r+')      # ditto, but with red plusses          If *x* and/or *y* is 2-dimensional, then the corresponding columns     will be plotted.          An arbitrary number of *x*, *y*, *fmt* groups can be     specified, as in::              a.plot(x1, y1, 'g^', x2, y2, 'g-')          Return value is a list of lines that were added.          The following format string characters are accepted to control     the line style or marker:          ================    ===============================     character           description     ================    ===============================     ``'-'``             solid line style     ``'--'``            dashed line style     ``'-.'``            dash-dot line style     ``':'``             dotted line style     ``'.'``             point marker     ``','``             pixel marker     ``'o'``             circle marker     ``'v'``             triangle_down marker     ``'^'``             triangle_up marker     ``''``             triangle_right marker     ``'1'``             tri_down marker     ``'2'``             tri_up marker     ``'3'``             tri_left marker     ``'4'``             tri_right marker     ``'s'``             square marker     ``'p'``             pentagon marker     ``'*'``             star marker     ``'h'``             hexagon1 marker     ``'H'``             hexagon2 marker     ``'+'``             plus marker     ``'x'``             x marker     ``'D'``             diamond marker     ``'d'``             thin_diamond marker     ``'|'``             vline marker     ``'_'``             hline marker     ================    ===============================          The following color abbreviations are supported:          ==========  ========     character   color     ==========  ========     'b'         blue     'g'         green     'r'         red     'c'         cyan     'm'         magenta     'y'         yellow     'k'         black     'w'         white     ==========  ========          In addition, you can specify colors in many weird and     wonderful ways, including full names (``'green'``), hex     strings (``'#008000'``), RGB or RGBA tuples (``(0,1,0,1)``) or     grayscale intensities as a string (``'0.8'``).  Of these, the     string specifications can be used in place of a ``fmt`` group,     but the tuple forms can be used only as ``kwargs``.          Line styles and colors are combined in a single format string, as in     ``'bo'`` for blue circles.          The *kwargs* can be used to set line properties (any property that has     a ``set_*`` method).  You can use this to set a line label (for auto     legends), linewidth, anitialising, marker face color, etc.  Here is an     example::              plot([1,2,3], [1,2,3], 'go-', label='line 1', linewidth=2)         plot([1,2,3], [1,4,9], 'rs',  label='line 2')         axis([0, 4, 0, 10])         legend()          If you make multiple lines with one plot command, the kwargs     apply to all those lines, e.g.::              plot(x1, y1, x2, y2, antialised=False)          Neither line will be antialiased.          You do not need to use format strings, which are just     abbreviations.  All of the line properties can be controlled     by keyword arguments.  For example, you can set the color,     marker, linestyle, and markercolor with::              plot(x, y, color='green', linestyle='dashed', marker='o',              markerfacecolor='blue', markersize=12).  See              :class:`~matplotlib.lines.Line2D` for details.          The kwargs are :class:`~matplotlib.lines.Line2D` properties:            agg_filter: unknown       alpha: float (0.0 transparent through 1.0 opaque)                animated: [True | False]                antialiased or aa: [True | False]                axes: an :class:`~matplotlib.axes.Axes` instance                clip_box: a :class:`matplotlib.transforms.Bbox` instance                clip_on: [True | False]                clip_path: [ (:class:`~matplotlib.path.Path`,         :class:`~matplotlib.transforms.Transform`) |         :class:`~matplotlib.patches.Patch` | None ]                color or c: any matplotlib color                contains: a callable function                dash_capstyle: ['butt' | 'round' | 'projecting']                dash_joinstyle: ['miter' | 'round' | 'bevel']                dashes: sequence of on/off ink in points                data: 2D array (rows are x, y) or two 1D arrays                drawstyle: [ 'default' | 'steps' | 'steps-pre' | 'steps-mid' | 'steps-post' ]                figure: a :class:`matplotlib.figure.Figure` instance                fillstyle: ['full' | 'left' | 'right' | 'bottom' | 'top']                gid: an id string                label: any string                linestyle or ls: [ ``'-'`` | ``'--'`` | ``'-.'`` | ``':'`` | ``'None'`` | ``' '`` | ``''`` ]         and any drawstyle in combination with a linestyle, e.g. ``'steps--'``.                linewidth or lw: float value in points                lod: [True | False]                marker: [ ``7`` | ``4`` | ``5`` | ``6`` | ``'o'`` | ``'D'`` | ``'h'`` | ``'H'`` | ``'_'`` | ``''`` | ``None`` | ``'None'`` | ``' '`` | ``'8'`` | ``'p'`` | ``','`` | ``'+'`` | ``'.'`` | ``'s'`` | ``'*'`` | ``'d'`` | ``3`` | ``0`` | ``1`` | ``2`` | ``'1'`` | ``'3'`` | ``'4'`` | ``'2'`` | ``'v'`` | ``''`` | ``'^'`` | ``'|'`` | ``'x'`` | ``'$...$'`` | *tuple* | *Nx2 array* ]       markeredgecolor or mec: any matplotlib color                markeredgewidth or mew: float value in points                markerfacecolor or mfc: any matplotlib color                markerfacecoloralt or mfcalt: any matplotlib color                markersize or ms: float                markevery: None | integer | (startind, stride)       picker: float distance in points or callable pick function         ``fn(artist, event)``                pickradius: float distance in points                rasterized: [True | False | None]                snap: unknown       solid_capstyle: ['butt' | 'round' |  'projecting']                solid_joinstyle: ['miter' | 'round' | 'bevel']                transform: a :class:`matplotlib.transforms.Transform` instance                url: a url string                visible: [True | False]                xdata: 1D array                ydata: 1D array                zorder: any number                   kwargs *scalex* and *scaley*, if defined, are passed on to     :meth:`~matplotlib.axes.Axes.autoscale_view` to determine     whether the *x* and *y* axes are autoscaled; the default is     *True*.          Additional kwargs: hold = [True|False] overrides default hold state