code: def correl_table(params):
      """Return a printable correlation table for a Parameters object."""
      varnames = [vname for vname in params if params[vname].vary]
      nwid = max(8, max([len(vname) for vname in varnames])) + 1
  
      def sfmt(a):
          return f" {a:{nwid}s}"
  
      def ffmt(a):
          return sfmt(f"{a:+.4f}")
  
      title = ["", sfmt("Variable")]
      title.extend([sfmt(vname) for vname in varnames])
  
      title = "|".join(title) + "|"
      bar = (
          [""]
          + ["-" * (nwid + 1) for i in range(len(varnames) + 1)]
          + [""]
      )
      bar = "+".join(bar)
  
      buff = [bar, title, bar]
  
      for vname, par in params.items():
          if not par.vary:
              continue
          line = ["", sfmt(vname)]
          for vother in varnames:
              if vother == vname:
                  line.append(ffmt(1))
              elif vother in par.correl:
                  line.append(ffmt(par.correl[vother]))
              else:
                  line.append("unknown")
          buff.append("|".join(line) + "|")
      buff.append(bar)
      return "\n".join(buff)
  
file_path: lmfit-py/lmfit/printfuncs.py
imports: from math import log10
  import re
  import numpy
label_desc: Use image node_id 9 for calling a global function with example usage: correl_table(params) and returns: str, str, a, sfmt