Debugging and Internals Access ------------------------------ .. seealso:: :func:`neuron.nrn_dll` Namespace Related ~~~~~~~~~~~~~~~~~ .. function:: name_declared Syntax: ``type = h.name_declared("name")`` ``type = h.name_declared("name", 1)`` ``type = h.name_declared("name", 2)`` Description: Return 0 if the name is not in the NEURON/HOC symbol table. The first form looks for names in the top level symbol table. The second form looks in the current object context. The last form also looks in the top level symbol table but is useful in Python to distinguish subtypes of variables which appear as doubles in HOC but internally are really not doubles and so cannot be pointed to by double*, eg. h.secondorder which is or h.nseg which returns either ``TypeError: Section access unspecified`` or ``nseg not a USERPROPERTY that can be pointed to`` If the name exists return 2 if an objref 3 if a Section 4 if a :ref:`strdef ` 5 if a scalar or :ref:`double ` variable. (if second arg is not 2) if second arg is 2 5 if a scalar double 6 if a double array 7 if an integer 8 if a section property 1 otherwise .. :: A HOC work-around that is not relevant in Python. Note that names can be (re)declared only if they do not already exist or are already of the same type. This is too useful to require the user to waste an objref in creating a :class:`StringFunctions` class to use :meth:`~StringFunctions.is_name`. .. code-block:: none name_declared("nrnmainmenu_") {object_push(nrnmainmenu_) print name_declared("ldfile", 0) object_pop()} {object_push(nrnmainmenu_) print name_declared("ldfile", 1) object_pop()} .. note:: This function checks the NEURON/HOC symbol table; Python objects are handled separately. To test if a simple name is a local variable in Python, use: .. code-block:: python if 'soma' in locals(): # do something Checking against ``globals()`` and ``dir()`` are also often useful. If the name is known in advance, use a ``try``/``except`` block and catch NameError and AttributeError: .. code-block:: python try: h.soma.squiggle except (NameError, AttributeError): print('Name does not exist') Combining this with an ``eval`` can allow testing arbitrary names, but is potentially unsafe as it allows execution of arbitrary code. ---- .. function:: symbols Name: symbols --- type the names of HOC functions and variables Syntax: ``h.symbols()`` Description: Types a list of functions and variable names defined in HOC. Dimensions of arrays are also indicated. .. warning:: No longer works. The nearest replacement is :func:`SymChooser` . Object Related ~~~~~~~~~~~~~~ .. function:: object_id Syntax: ``h.object_id(objref)`` ``h.object_id(objref, 1)`` Description: Returns 0 if the object reference does not point to an object instance. (Otherwise returns the pointer cast to a double, not a very useful number, except that this is equal to the value returned by Python's ``hash`` function.) If the second argument is 1, it returns the index of the object name. Returns -1 if the object is the NULLObject. Example: .. code-block:: python from neuron import h a, b, c = h.List(), h.List(), h.Vector() print(h.object_id(a)) # displays a double; equal to hash(a) print(h.object_id(a, 1)) # 0 since a == h.List[0] print(h.object_id(b, 1)) # 1 since b == h.List[1] print(h.object_id(c, 1)) # 0 since c == h.Vector[0] ---- .. function:: allobjectvars Syntax: ``h.allobjectvars()`` Description: Prints all the HOC object references (objref variables) that have been declared along with the class type of the object they reference and the number of references. Objects created via Python and not assigned to a HOC objref Example: .. code-block:: python >>> h('objref foo') 1 >>> h.foo = h.Vector() >>> h.allobjectvars() obp hoc_obj_[0] -> NULL obp hoc_obj_[1] -> NULL obp foo[0] -> Vector[0] with 1 refs. 0.0 >>> banana = h.foo >>> h.allobjectvars() obp hoc_obj_[0] -> NULL obp hoc_obj_[1] -> NULL obp foo[0] -> Vector[0] with 2 refs. 0.0 ---- .. function:: allobjects Syntax: ``h.allobjects()`` ``h.allobjects("templatename")`` ``nref = h.allobjects(objectref)`` Description: Prints the internal names of all class instances (objects) available from the interpreter along with the number of references to them. With a templatename the list is restricted to objects of that class. With an object variable, nothing is printed but the reference count is returned. The count is too large by one if the argument was of the form templatename[index] since a temporary reference is created while the object is on the stack during the call. Example: .. code-block:: python >>> v = h.Vector() >>> foo = h.List() >>> h.allobjects() List[0] with 1 refs Vector[0] with 1 refs 0.0 >>> h.allobjects('Vector') Vector[0] with 1 refs 0.0 >>> h.allobjects(foo) 2.0 ---- .. function:: object_push Syntax: ``h.object_push(objref)`` Description: Enter the context of the object referenced by objref. In this context you can directly access any variables or call any functions, even those not declared as :ref:`public `. Do not attempt to create any new symbol names! This function is generally used by the object itself to save its state in a session. ---- .. function:: object_pop Syntax: ``h.object_pop()`` Description: Pop the last object from an :func:`object_push` . ---- Miscellaneous ~~~~~~~~~~~~~ .. function:: hoc_pointer_ Syntax: ``h.hoc_pointer_(&variable)`` Description: A function used by c and c++ implementations to request a pointer to the variable from its interpreter name. Not needed by or useful for the user; returns 1.0 on success.