code: def isreal(ds):
      """Has a numeric measure
  
      >>> isreal('float32')
      True
      >>> isreal('3 * ?real')
      True
      >>> isreal('string')
      False
      """
      ds = launder(ds)
      return isinstance(ds, Unit) and ds in floating
  
file_path: datashader/datashader/datashape/predicates.py
imports: import numpy
  from .util import collect, dshape
  from .internal_utils import remove
  from .coretypes import DataShape, Fixed, Var, Ellipsis, Record, Unit, date_, datetime_, TypeVar, to_numpy_dtype, Categorical
  from .typesets import floating, boolean
label_desc: Use image node_id 11 for calling a global function with example usage: isreal(ds) and returns: unknown