.. _ticks_and_spines-tick_labels_from_values:

ticks_and_spines example code: tick_labels_from_values.py
=========================================================



.. plot:: /home/tcaswell/source/p/matplotlib/doc/mpl_examples/ticks_and_spines/tick_labels_from_values.py

::

    """
    
    Basic demo showing how to set tick labels to values of a series.
    
    Using ax.set_xticks causes the tick labels to be set on the currently
    chosen ticks. However, you may want to allow matplotlib to dynamically
    choose the number of ticks and their spacing.
    
    In this case it may be better to determine the tick label from the
    value at the tick. The following example shows how to do this.
    
    NB: The MaxNLocator is used here to ensure that the tick values
    take integer values.
    
    """
    
    import matplotlib.pyplot as plt
    from matplotlib.ticker import FuncFormatter, MaxNLocator
    fig = plt.figure()
    ax = fig.add_subplot(111)
    xs = range(26)
    ys = range(26)
    labels = list('abcdefghijklmnopqrstuvwxyz')
    
    
    def format_fn(tick_val, tick_pos):
        if int(tick_val) in xs:
            return labels[int(tick_val)]
        else:
            return ''
    ax.xaxis.set_major_formatter(FuncFormatter(format_fn))
    ax.xaxis.set_major_locator(MaxNLocator(integer=True))
    ax.plot(xs, ys)
    plt.show()
    

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