def plot_coherence(xdata, ydata, std_error, fit, fit_function, xunit, exp_str,<EOL>qubit_label):
if not HAS_MATPLOTLIB:<EOL><INDENT>raise ImportError('<STR_LIT>'<EOL>'<STR_LIT>')<EOL><DEDENT>plt.errorbar(xdata, ydata, std_error, marker='<STR_LIT:.>',<EOL>markersize=<NUM_LIT:9>, c='<STR_LIT:b>', linestyle='<STR_LIT>')<EOL>plt.plot(xdata, fit_function(xdata, *fit), c='<STR_LIT:r>', linestyle='<STR_LIT>',<EOL>label=(exp_str + '<STR_LIT>' % (str(round(fit[<NUM_LIT:1>])), xunit)))<EOL>plt.xticks(fontsize=<NUM_LIT>, rotation=<NUM_LIT>)<EOL>plt.yticks(fontsize=<NUM_LIT>)<EOL>plt.xlabel('<STR_LIT>' % (xunit), fontsize=<NUM_LIT:16>)<EOL>plt.ylabel('<STR_LIT>', fontsize=<NUM_LIT:16>)<EOL>plt.title(exp_str + '<STR_LIT>' % (str(qubit_label)), fontsize=<NUM_LIT>)<EOL>plt.legend(fontsize=<NUM_LIT:12>)<EOL>plt.grid(True)<EOL>plt.show()<EOL>
Plot coherence data.

    Args:
        xdata
        ydata
        std_error
        fit
        fit_function
        xunit
        exp_str
        qubit_label
    Raises:
        ImportError: If matplotlib is not installed.