How to set resolution / number of ticks on bar graph

It seems I can only have a max of 7 labels displayed on my graph how
do I increase that?

        self.axes.clear()

        vals = self.plotInfo.getYValues()
        self.axes.set_xticks = range(len(vals))
        self.axes.set_xticklabels(self.plotInfo.getXValues())
        self.axes.bar(
            left=range(len(vals)),
            height=map(float, vals),
            width=.2,
            align='center',
            alpha=0.44,
            picker=5)

        msg = self.plotInfo.annotation.message
        if msg != None:
            self.axes.set_title(self.plotInfo.annotation.message)
        self.axes.set_xlabel(self.plotInfo.xCol, fontsize=6)
        self.axes.set_ylabel(self.plotInfo.yCol, fontsize=6)

        self.fig.autofmt_xdate()
        self.resetLabels()

Cheers,
  lars

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