code: def find_best_blas_type(arrays=(), dtype=None):
      """Find best-matching BLAS/LAPACK type.
  
      Arrays are used to determine the optimal prefix of BLAS routines.
  
      Parameters
      ----------
      arrays : sequence of ndarrays, optional
          Arrays can be given to determine optimal prefix of BLAS
          routines. If not given, double-precision routines will be
          used, otherwise the most generic type in arrays will be used.
      dtype : str or dtype, optional
          Data-type specifier. Not used if `arrays` is non-empty.
  
      Returns
      -------
      prefix : str
          BLAS/LAPACK prefix character.
      dtype : dtype
          Inferred Numpy data type.
      prefer_fortran : bool
          Whether to prefer Fortran order routines over C order.
  
      Examples
      --------
      >>> import scipy.linalg.blas as bla
      >>> a = np.random.rand(10,15)
      >>> b = np.asfortranarray(a)  # Change the memory layout order
      >>> bla.find_best_blas_type((a,))
      ('d', dtype('float64'), False)
      >>> bla.find_best_blas_type((a*1j,))
      ('z', dtype('complex128'), False)
      >>> bla.find_best_blas_type((b,))
      ('d', dtype('float64'), True)
  
      """
      dtype = _np.dtype(dtype)
      prefer_fortran = False
  
      if arrays:
          # use the most generic type in arrays
          dtypes = [ar.dtype for ar in arrays]
          dtype = _np.find_common_type(dtypes, ())
          try:
              index = dtypes.index(dtype)
          except ValueError:
              index = 0
          if arrays[index].flags["FORTRAN"]:
              # prefer Fortran for leading array with column major order
              prefer_fortran = True
  
      prefix = _type_conv.get(dtype.char, "d")
      if dtype.char == "G":
          # complex256 -> complex128 (i.e., C long double -> C double)
          dtype = _np.dtype("D")
      elif dtype.char not in "fdFD":
          dtype = _np.dtype("d")
  
      return prefix, dtype, prefer_fortran
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from scipy.linalg import _fblas
  from scipy.linalg._fblas import *
label_desc: Use image node_id 1 for calling a global function with example usage: find_best_blas_type(arrays, dtype) and returns: prefix,  dtype,  prefer_fortran