code: def diagnostics_contpix(self, data, nchunks=10, fig = "baseline_spec_with_cont_pix"):
          
          if data.contmask is None:
              print("No contmask set")
          else:
              coeffs_all = self.coeffs
              wl = data.wl
              baseline_spec = coeffs_all[:,0]
              contmask = data.contmask
              contpix_x = wl[contmask]
              contpix_y = baseline_spec[contmask]
              rem = len(wl)%nchunks
              wl_split = np.array(np.split(wl[0:len(wl)-rem],nchunks))
              baseline_spec_split = np.array(
                      np.split(baseline_spec[0:len(wl)-rem],nchunks))
              nchunks = wl_split.shape[0]
              for i in range(nchunks):
                  fig_chunk = fig + "_%s" %str(i)
                  wl_chunk = wl_split[i,:]
                  baseline_spec_chunk = baseline_spec_split[i,:]
                  take = np.logical_and(
                          contpix_x>wl_chunk[0], contpix_x<wl_chunk[-1])
                  self.plot_contpix(
                          wl_chunk, baseline_spec_chunk, 
                          contpix_x[take], contpix_y[take], fig_chunk)
docs: Call plot_contpix once for each nth of the spectrum