How to use the nexusformat.nexus.NXfield function in nexusformat

#histogram and normalize 
        norm, nbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb))
        hist, hbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb), weights=datain)
        if self.entry['data'].nxerrors:
            histe, hbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb), weights=errorsin*errorsin)
            histe = histe**0.5
            err = histe/norm

        I = NXfield(hist/norm, name='S(Q,E)')

        Qb = NXfield(Qb[:-1]+dQ/2., name='Q')
        Eb = NXfield(Eb[:-1]+dE/2., name='E')

        result = NXdata(I, (Eb, Qb))
        if self.entry.data.nxerrors:
            result.errors = NXfield(err)
        return result

qmax = Q.max()
        emin = E.min()
        emax = E.max()
        NQ = int((qmax-qmin)/dQ) + 1
        NE = int((emax-emin)/dE) + 1
        Qb = np.linspace(qmin, qmax, NQ)
        Eb = np.linspace(emin, emax, NE)
        #histogram and normalize 
        norm, nbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb))
        hist, hbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb), weights=datain)
        if self.entry['data'].nxerrors:
            histe, hbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb), weights=errorsin*errorsin)
            histe = histe**0.5
            err = histe/norm

        I = NXfield(hist/norm, name='S(Q,E)')

        Qb = NXfield(Qb[:-1]+dQ/2., name='Q')
        Eb = NXfield(Eb[:-1]+dE/2., name='E')

        result = NXdata(I, (Eb, Qb))
        if self.entry.data.nxerrors:
            result.errors = NXfield(err)
        return result

"""
        if self.ndim > 2:
            idx=[np.s_[0] if s==1 else np.s_[:] for s in self.data.nxsignal.shape]
            for i in range(len(idx)):
                if idx.count(slice(None,None,None)) > 2:
                    idx[i] = 0
            self.signal = self.data.nxsignal[tuple(idx)][()]
        elif self.rgb_image:
            self.signal = self.data.nxsignal[()]
        else:
            self.signal = self.data.nxsignal[()].reshape(self.shape)

        if self.data.plot_axes is not None:
            axes = self.data.plot_axes
        else:
            axes = [NXfield(np.arange(self.shape[i]), name='Axis%s'%i)
                            for i in range(self.ndim)]

        self.axes = [NXfield(axes[i].nxdata, name=axes[i].nxname,
                             attrs=axes[i].safe_attrs) for i in range(self.ndim)]

        if over:
            self.axis['signal'].set_data(self.signal)
        else:
            self.axis = {}
            self.axis['signal'] = NXPlotAxis(self.signal)

        for i in range(self.ndim):
            if over:
                self.axis[i].set_data(self.axes[i], self.shape[i])
            else:
                self.axis[i] = NXPlotAxis(self.axes[i], i, self.shape[i])

qmax = Q.max()
        emin = E.min()
        emax = E.max()
        NQ = int((qmax-qmin)/dQ) + 1
        NE = int((emax-emin)/dE) + 1
        Qb = np.linspace(qmin, qmax, NQ)
        Eb = np.linspace(emin, emax, NE)
        #histogram and normalize 
        norm, nbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb))
        hist, hbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb), weights=datain)
        if self.entry['data'].nxerrors:
            histe, hbin = np.histogramdd((Ein,Qin), bins=(Eb,Qb), weights=errorsin*errorsin)
            histe = histe**0.5
            err = histe/norm

        I = NXfield(hist/norm, name='S(Q,E)')

        Qb = NXfield(Qb[:-1]+dQ/2., name='Q')
        Eb = NXfield(Eb[:-1]+dE/2., name='E')

        result = NXdata(I, (Eb, Qb))
        if self.entry.data.nxerrors:
            result.errors = NXfield(err)
        return result

for i in range(len(idx)):
                if idx.count(slice(None,None,None)) > 2:
                    idx[i] = 0
            self.signal = self.data.nxsignal[tuple(idx)][()]
        elif self.rgb_image:
            self.signal = self.data.nxsignal[()]
        else:
            self.signal = self.data.nxsignal[()].reshape(self.shape)

        if self.data.plot_axes is not None:
            axes = self.data.plot_axes
        else:
            axes = [NXfield(np.arange(self.shape[i]), name='Axis%s'%i)
                            for i in range(self.ndim)]

        self.axes = [NXfield(axes[i].nxdata, name=axes[i].nxname,
                             attrs=axes[i].safe_attrs) for i in range(self.ndim)]

        if over:
            self.axis['signal'].set_data(self.signal)
        else:
            self.axis = {}
            self.axis['signal'] = NXPlotAxis(self.signal)

        for i in range(self.ndim):
            if over:
                self.axis[i].set_data(self.axes[i], self.shape[i])
            else:
                self.axis[i] = NXPlotAxis(self.axes[i], i, self.shape[i])
                self.axis[i].dim = i

        if self.ndim == 1:

def plot_axis(axis):
            return NXfield(axis.nxvalue, name=axis.nxname, attrs=axis.attrs) 
        axis_name = self.axis_boxes[axis].currentText()