- Syntax:
obj = h.StringFunctions()- Description:
- The StringFunctions class contains functions which you can apply to a
strdef. This class exists purely for the utility of preventing pollution of name space with string operations.
Example:
from neuron import h sf = h.StringFunctions()
.. method:: StringFunctions.len
Syntax:
``length = strobj.len(str)``
Description:
Return the length of a string.
Example:
.. code-block::
python
from neuron import h
s = h.ref("hello")
sf = h.StringFunctions()
length = sf.len(s)
print(length)
.. method:: StringFunctions.substr
Syntax:
``index = strobj.substr(s1, s2)``
Description:
Return the index into *s1* of the first occurrence of *s2*.
If *s2* isn't a substring then the return value is -1.
Example:
.. code-block::
python
from neuron import h
s1 = h.ref("allowed")
s2 = h.ref("low")
sf = h.StringFunctions()
index = sf.substr(s1, s2)
.. method:: StringFunctions.head
Syntax:
``strobj.head(str, "regexp", result)``
Description:
The result contains the head of the string
up to but not including the *regexp*. returns index of
last char.
Example:
.. code-block::
python
from neuron import h
s1 = h.ref("hello world")
s2 = h.ref("")
sf = h.StringFunctions()
index = sf.head(s1, "[e]", s2)
print(s2[0])
.. method:: StringFunctions.tail
Syntax:
``strobj.tail(str, "regexp", result)``
Description:
The result contains the tail of the string
from the char following *regexp* to the end of the string.
return index of first char.
Other functions can be added as needed,
eg., \ ``index(s1, c1)``, \ ``char(s1, i)``, etc.
without polluting the global name space. In recent versions
functions can return strings.
Example:
.. code-block::
python
from neuron import h
s1 = h.ref("hello world")
s2 = h.ref("")
sf = h.StringFunctions()
index = sf.tail(s1, "[e]", s2)
print(s2[0])
.. method:: StringFunctions.right
Syntax:
``strobj.right(str, n)``
Description:
Removes first n characters from *str* and puts the result in
*str*.
Example:
.. code-block::
python
from neuron import h
s = h.ref("hello")
sf = h.StringFunctions()
sf.right(s, 3)
print(s[0])
.. method:: StringFunctions.left
Syntax:
``.left(str, n)``
Description:
Removes all but first n characters from *str* and puts the
result in *str*
Example:
.. code-block::
python
from neuron import h
s = h.ref("hello")
sf = h.StringFunctions()
sf.left(s, 3)
print(s[0])
.. method:: StringFunctions.is_name
Syntax:
``.is_name(item)``
Description:
Returns True if the *item* is the name of a symbol, False otherwise.
This is so useful that the same thing is available with the top level
:func:`name_declared` function (except that returns 1 or 0 instead of True
or False).
Example:
.. code-block::
python
from neuron import h
s1 = h.ref("hello world")
sf = h.StringFunctions()
name = sf.is_name(s1)
print(name)
Here is an example with one string that works,
and another that does not:
.. code-block::
python
from neuron import h
sf = h.StringFunctions()
# valid name
print(sf.is_name("xvalue"))
# invalid name
print(sf.is_name("xsquiggle"))
.. note::
This is approximately equivalent to ``item in dir(h)``.
.. method:: StringFunctions.alias
Syntax:
``.alias(obj, "name", &var2)``
``.alias(obj, "name", obj2)``
``.alias(obj, "name")``
``.alias(obj)``
Description:
"name" becomes a public variable for obj and points to the
scalar var2 or object obj2. obj.name may be used anywhere the var2 or obj2 may
be used. With no third arg, the "name" is removed from the objects
alias list. With no second arg, the objects alias list is cleared.
Example:
.. code-block::
python
from neuron import h
sf = h.StringFunctions()
v = h.Vector()
sf.alias(v, 't', h._ref_t)
print('v.t = %g' % v.t)
h.t = 42
print('v.t = %g' % v.t)
.. method:: StringFunctions.alias_list
Syntax:
``list = sf.alias_list(obj)``
Description:
Return a new List object containing String objects which contain
the alias names.
.. warning::
The String class is not a built-in class. It generally gets declared when
the nrngui.hoc file is loaded and lives in stdlib.hoc.
Note that the String class must exist and its
constructor must allow a single strdef argument. Minimally:
Example:
.. code-block::
python
from neuron import h
h.load_file('stdrun.hoc')
sf = h.StringFunctions()
v = h.Vector()
al = sf.alias_list(v)
print(al)
.. method:: StringFunctions.references
Syntax:
``sf.references(object)``
Description:
Prints the number of references to the object and all objref names
that reference that object (including references via
:class:`HBox`, :class:`VBox`, and :class:`List`). It also prints the number of references found.
Example:
.. code-block::
python
from neuron import h
s1 = h.Section(name='soma')
strobj = h.StringFunctions()
strobj.references(s1)
.. method:: StringFunctions.is_point_process
Syntax:
``i = sf.is_point_process(object)``
Description:
Returns 0 if the object is not a POINT_PROCESS. Otherwise
returns the point type (which is always 1 greater than the index into the
:func:`MechanismType(1) <MechanismType>` list).
Example:
.. code-block::
python
from neuron import h
h.load_file('stdrun.hoc')
s1 = h.Section(name='soma')
syn = h.ExpSyn(s1(0.5))
sf = h.StringFunctions()
# not point process
print(sf.is_point_process(s1))
# point process
print(sf.is_point_process(syn))
c = h.IntFire1()
# point process
print(ssf.is_point_process(c))
.. method:: StringFunctions.is_artificial
Syntax:
``i = sf.is_artificial(object)``
Description:
Returns 0 if the object is not an ARTIFICIAL_CELL. Otherwise
returns the point type (which is always 1 greater than the index into the
:func:`MechanismType(1) <MechanismType>` list).
Example:
.. code-block::
python
from neuron import h
h.load_file('stdrun.hoc')
s1 = h.Section(name='soma')
syn = h.ExpSyn(s1(0.5))
# initiate string function
sf = h.StringFunctions()
c = h.IntFire1()
# artificial
print(sf.is_artificial(c))
# not artificial
print(sf.is_artificial(syn))