Want to width of histogram

HoloViews
1

Hi,
I just want to width of histogram as 350 . But it failed.

       self.image = hv.Image(self._get_data(self.data), bounds=self.bounds)
        ropts = dict(colorbar=True, tools=["hover"], cmap='Viridis_r',alpha=0.7,cnorm="linear",width=1050,height=700)
        self.r2=rasterize(self.image)
        self.plot = tiles * self.r2.opts(**ropts).hist().opts(width=350).redim.label(z='Count')

regards