def __init__(self, group, inputcode, language, level=0):
self.namespace = namespace(inputcode, level=level+1)
self.inputcode = inputcode
self.language = language
P = group
ns = self.namespace
self.inputcode = freeze_with_equations(self.inputcode, P._eqs, ns)
statements = statements_from_codestring(self.inputcode, P._eqs,
infer_definitions=True)
block = Block(*statements)
symbols = get_neuron_group_symbols(P, self.language,
index='_neuron_index')
if language.name=='python' or language.name=='c':
symbols['_neuron_index'] = ArrayIndex('_neuron_index',
'_spikes',
self.language,
array_len='_numspikes')
if language.name=='gpu':
symbols['_neuron_index'] = SliceIndex('_neuron_index',
'0',
'_num_neurons',
self.language,
all=True)
_spiked_symbol = group._threshold._spiked_symbol
symbols['_spiked'] = _spiked_symbol
block = CIfBlock('_spiked', [block])
self.namespace['_num_gpu_indices'] = len(P)
self.namespace['t'] = 1.0 # dummy value
self.namespace['_num_neurons'] = len(P)
self.code = block.generate('reset', self.language, symbols,
namespace=ns)
ns = self.code.namespace
ns['dt'] = P.clock._dt
log_info('brian.codegen2.CodeGenReset', 'CODE:\n'+self.code.code_str)
log_info('brian.codegen2.CodeGenReset', 'KEYS:\n'+str(ns.keys()))
def __init__(self, inputcode, language, level=0):
self._ns, unknowns = namespace(inputcode,
level=level + 1,
return_unknowns=True)
self._inputcode = inputcode
self._language = language
self._prepared = False
def __init__(self, expr, level=0):
self._namespace, unknowns = namespace(expr, level=level + 1, return_unknowns=True)
self._vars = unknowns
self._expr = expr
self._code = compile(expr, "StringThreshold", "eval")
class Replacer(object):
def __init__(self, func, n):
self.n = n
self.func = func
def __call__(self):
return self.func(self.n)
self._Replacer = Replacer
def __init__(self, expr, level=0):
self._namespace, unknowns = namespace(expr, level=level + 1, return_unknowns=True)
self._vars = unknowns
self._expr = expr
self._code = compile(expr, "StringThreshold", "eval")
class Replacer(object):
def __init__(self, func, n):
self.n = n
self.func = func
def __call__(self):
return self.func(self.n)
self._Replacer = Replacer
def _interpret(self, value, synapses, level):
'''
Interprets value string in the context of the synaptic indexes synapses
'''
_namespace = namespace(value, level=level)
code = compile(value, "StringAssignment", "eval")
synapses = slice_to_array(synapses, N=len(self.synapses))
_namespace['n'] = len(synapses)
_namespace['i'] = self.synapses.presynaptic[synapses]
_namespace['j'] = self.synapses.postsynaptic[synapses]
for var in self.synapses.var_index: # maybe synaptic variables should have higher priority
if isinstance(var, str):
_namespace[var] = self.synapses.state(var)[synapses]
_namespace['rand'] = self._Replacer(np.random.rand, len(synapses))
_namespace['randn'] = self._Replacer(np.random.randn, len(synapses))
return eval(code, _namespace)
def _interpret(self, value, synapses, level):
'''
Interprets value string in the context of the synaptic indexes synapses
'''
_namespace = namespace(value, level=level)
code = compile(value, "StringAssignment", "eval")
synapses=slice_to_array(synapses,N=len(self.synapses))
_namespace['n']=len(synapses)
_namespace['i']=self.synapses.presynaptic[synapses]
_namespace['j']=self.synapses.postsynaptic[synapses]
for var in self.synapses.var_index: # maybe synaptic variables should have higher priority
if isinstance(var,str):
_namespace[var] = self.synapses.state(var)[synapses]
_namespace['rand'] = self._Replacer(np.random.rand, len(synapses))
_namespace['randn'] = self._Replacer(np.random.randn, len(synapses))
return eval(code, _namespace)
def __init__(self, group, inputcode, language, level=0):
self.namespace = namespace(inputcode, level=level + 1)
self.inputcode = inputcode
self.language = language
P = group
ns = self.namespace
self.inputcode = freeze_with_equations(self.inputcode, P._eqs, ns)
statements = statements_from_codestring(self.inputcode,
P._eqs,
infer_definitions=True)
block = Block(*statements)
symbols = get_neuron_group_symbols(P,
self.language,
index='_neuron_index')
if language.name == 'python' or language.name == 'c':
symbols['_neuron_index'] = ArrayIndex('_neuron_index',
'_spikes',
self.language,
array_len='_numspikes')
if language.name == 'gpu':
symbols['_neuron_index'] = SliceIndex('_neuron_index',
'0',
'_num_neurons',
self.language,
all=True)
_spiked_symbol = group._threshold._spiked_symbol
symbols['_spiked'] = _spiked_symbol
block = CIfBlock('_spiked', [block])
self.namespace['_num_gpu_indices'] = len(P)
self.namespace['t'] = 1.0 # dummy value
self.namespace['_num_neurons'] = len(P)
self.code = block.generate('reset',
self.language,
symbols,
namespace=ns)
ns = self.code.namespace
ns['dt'] = P.clock._dt
log_info('brian.codegen2.CodeGenReset', 'CODE:\n' + self.code.code_str)
log_info('brian.codegen2.CodeGenReset', 'KEYS:\n' + str(ns.keys()))
def select_threshold(expr, eqs, level=0):
'''
Automatically selects the appropriate Threshold object from a string.
Matches the following patterns:
var_name > or >= const : Threshold
var_name > or >= var_name : VariableThreshold
others : StringThreshold
'''
global CThreshold, PythonThreshold
use_codegen = (get_global_preference('usecodegen') and
get_global_preference('usecodegenthreshold'))
use_weave = (get_global_preference('useweave') and
get_global_preference('usecodegenweave'))
if use_codegen:
if CThreshold is None:
from brian.experimental.codegen.threshold import (CThreshold,
PythonThreshold)
if use_weave:
log_warn('brian.threshold', 'Using codegen CThreshold')
return CThreshold(expr, level=level + 1)
else:
log_warn('brian.threshold', 'Using codegen PythonThreshold')
return PythonThreshold(expr, level=level + 1)
# plan:
# - see if it matches A > B or A >= B, if not select StringThreshold
# - check if A, B both match diffeq variable names, and if so
# select VariableThreshold
# - check that A is a variable name, if not select StringThreshold
# - extract all the identifiers from B, and if none of them are
# callable, assume it is a constant, try to eval it and then use
# Threshold. If not, or if eval fails, use StringThreshold.
# This misses the case of e.g. V>10*mV*exp(1) because exp will be
# callable, but in general a callable means that it could be
# non-constant.
expr = expr.strip()
eqs.prepare()
ns = namespace(expr, level=level + 1)
s = re.search(r'^\s*(\w+)\s*>=?(.+)', expr)
if not s:
return StringThreshold(expr, level=level + 1)
A = s.group(1)
B = s.group(2).strip()
if A not in eqs._diffeq_names:
return StringThreshold(expr, level=level + 1)
if B in eqs._diffeq_names:
return VariableThreshold(B, A)
try:
vars = get_identifiers(B)
except SyntaxError:
return StringThreshold(expr, level=level + 1)
all_vars = eqs._eq_names + eqs._diffeq_names + eqs._alias.keys() + ['t']
for v in vars:
if v not in ns or v in all_vars or callable(ns[v]):
return StringThreshold(expr, level=level + 1)
try:
val = eval(B, ns)
except:
return StringThreshold(expr, level=level + 1)
return Threshold(val, A)
def __call__(self, code):
ns = namespace(code, level=1)
for k, v in ns.iteritems():
if isinstance(v, Symbol):
code = re.sub("\\b" + k + "\\b", str(v), code)
self.outputcode.add(''.join(expr + ';\n' for expr in code.split('\n') if expr.strip()))
def __init__(self,
C,
eqs,
pre,
post,
wmin=0,
wmax=Inf,
level=0,
clock=None,
delay_pre=None,
delay_post=None):
NetworkOperation.__init__(self, lambda: None, clock=clock)
C.compress()
# Convert to equations object
if isinstance(eqs, Equations):
eqs_obj = eqs
else:
eqs_obj = Equations(eqs, level=level + 1)
# handle multi-line pre, post equations and multi-statement equations separated by ;
if '\n' in pre:
pre = flattened_docstring(pre)
elif ';' in pre:
pre = '\n'.join([line.strip() for line in pre.split(';')])
if '\n' in post:
post = flattened_docstring(post)
elif ';' in post:
post = '\n'.join([line.strip() for line in post.split(';')])
# Check units
eqs_obj.compile_functions()
eqs_obj.check_units()
# Get variable names
vars = eqs_obj._diffeq_names
# Find which ones are directly modified (e.g. regular expression matching; careful with comments)
vars_pre = [var for var in vars if var in modified_variables(pre)]
vars_post = [var for var in vars if var in modified_variables(post)]
# additional dependencies are used to ensure that if there are multiple
# pre/post separated equations they are grouped together as one
additional_deps = [
'__pre_deps=' + '+'.join(vars_pre),
'__post_deps=' + '+'.join(vars_post)
]
separated_equations = separate_equations(eqs_obj, additional_deps)
if not len(separated_equations) == 2:
print separated_equations
raise ValueError(
'Equations should separate into pre and postsynaptic variables.'
)
sep_pre, sep_post = separated_equations
for v in vars_pre:
if v in sep_post._diffeq_names:
sep_pre, sep_post = sep_post, sep_pre
break
index_pre = [
i for i in range(len(vars))
if vars[i] in vars_pre or vars[i] in sep_pre._diffeq_names
]
index_post = [
i for i in range(len(vars))
if vars[i] in vars_post or vars[i] in sep_post._diffeq_names
]
vars_pre = array(vars)[index_pre].tolist()
vars_post = array(vars)[index_post].tolist()
# Check pre/post consistency
shared_vars = set(vars_pre).intersection(vars_post)
if shared_vars != set([]):
raise Exception, str(
list(shared_vars)) + " are both presynaptic and postsynaptic!"
# Substitute equations/aliases into pre/post code
def substitute_eqs(code):
for name in sep_pre._eq_names[-1::-1] + sep_post._eq_names[
-1::-1]: # reverse order, as in equations.py
if name in sep_pre._eq_names:
expr = sep_pre._string[name]
else:
expr = sep_post._string[name]
code = re.sub("\\b" + name + "\\b", '(' + expr + ')', code)
return code
pre = substitute_eqs(pre)
post = substitute_eqs(post)
# Create namespaces for pre and post codes
pre_namespace = namespace(pre, level=level + 1)
post_namespace = namespace(post, level=level + 1)
def splitcode(incode):
num_perneuron = num_persynapse = 0
reordering_warning = False
incode_lines = [
line.strip() for line in incode.split('\n') if line.strip()
]
per_neuron_lines = []
per_synapse_lines = []
for line in incode_lines:
if not line.strip(): continue
m = re.search(
r'\bw\b\s*[^><=]?=',
line) # lines of the form w = ..., w *= ..., etc.
if m:
num_persynapse += 1
per_synapse_lines.append(line)
else:
num_perneuron += 1
if num_persynapse != 0 and not reordering_warning:
log_warn(
'brian.experimental.cstdp',
'STDP operations are being re-ordered, results may be wrong.'
)
reordering_warning = True
per_neuron_lines.append(line)
return per_neuron_lines, per_synapse_lines
per_neuron_pre, per_synapse_pre = splitcode(pre)
per_neuron_post, per_synapse_post = splitcode(post)
all_vars = vars_pre + vars_post + ['w']
per_neuron_pre = [
c_single_statement(freeze(line, all_vars, pre_namespace))
for line in per_neuron_pre
]
per_neuron_post = [
c_single_statement(freeze(line, all_vars, post_namespace))
for line in per_neuron_post
]
per_synapse_pre = [
c_single_statement(freeze(line, all_vars, pre_namespace))
for line in per_synapse_pre
]
per_synapse_post = [
c_single_statement(freeze(line, all_vars, post_namespace))
for line in per_synapse_post
]
per_neuron_pre = '\n'.join(per_neuron_pre)
per_neuron_post = '\n'.join(per_neuron_post)
per_synapse_pre = '\n'.join(per_synapse_pre)
per_synapse_post = '\n'.join(per_synapse_post)
# Neuron groups
G_pre = NeuronGroup(len(C.source), model=sep_pre, clock=self.clock)
G_post = NeuronGroup(len(C.target), model=sep_post, clock=self.clock)
G_pre._S[:] = 0
G_post._S[:] = 0
self.pre_group = G_pre
self.post_group = G_post
var_group = {}
for i, v in enumerate(vars_pre):
var_group[v] = G_pre
for i, v in enumerate(vars_post):
var_group[v] = G_post
self.var_group = var_group
self.contained_objects += [G_pre, G_post]
vars_pre_ind = {}
for i, var in enumerate(vars_pre):
vars_pre_ind[var] = i
vars_post_ind = {}
for i, var in enumerate(vars_post):
vars_post_ind[var] = i
prevars_dict = dict((k, G_pre.state(k)) for k in vars_pre)
postvars_dict = dict((k, G_post.state(k)) for k in vars_post)
clipcode = ''
if isfinite(wmin):
clipcode += 'if(w<%wmin%) w = %wmin%;\n'.replace(
'%wmin%', repr(float(wmin)))
if isfinite(wmax):
clipcode += 'if(w>%wmax%) w = %wmax%;\n'.replace(
'%wmax%', repr(float(wmax)))
if not isinstance(C, DelayConnection):
precode = iterate_over_spikes(
'_j', '_spikes',
(load_required_variables(
'_j', prevars_dict), transform_code(per_neuron_pre),
iterate_over_row(
'_k', 'w', C.W, '_j', (load_required_variables(
'_k', postvars_dict), transform_code(per_synapse_pre),
ConnectionCode(clipcode)))))
postcode = iterate_over_spikes(
'_j', '_spikes',
(load_required_variables(
'_j', postvars_dict), transform_code(per_neuron_post),
iterate_over_col('_i', 'w', C.W, '_j',
(load_required_variables('_i', prevars_dict),
transform_code(per_synapse_post),
ConnectionCode(clipcode)))))
log_debug('brian.experimental.c_stdp',
'CSTDP Pre code:\n' + str(precode))
log_debug('brian.experimental.c_stdp',
'CSTDP Post code:\n' + str(postcode))
connection_delay = C.delay * C.source.clock.dt
if (delay_pre is None) and (
delay_post is None): # same delays as the Connnection C
delay_pre = connection_delay
delay_post = 0 * ms
elif delay_pre is None:
delay_pre = connection_delay - delay_post
if delay_pre < 0 * ms:
raise AttributeError, "Postsynaptic delay is too large"
elif delay_post is None:
delay_post = connection_delay - delay_pre
if delay_post < 0 * ms:
raise AttributeError, "Postsynaptic delay is too large"
# create forward and backward Connection objects or SpikeMonitor objects
pre_updater = SpikeMonitor(C.source,
function=precode,
delay=delay_pre)
post_updater = SpikeMonitor(C.target,
function=postcode,
delay=delay_post)
updaters = [pre_updater, post_updater]
self.contained_objects += [pre_updater, post_updater]
else:
if delay_pre is not None or delay_post is not None:
raise ValueError(
"Must use delay_pre=delay_post=None for the moment.")
max_delay = C._max_delay * C.target.clock.dt
# Ensure that the source and target neuron spikes are kept for at least the
# DelayConnection's maximum delay
C.source.set_max_delay(max_delay)
C.target.set_max_delay(max_delay)
self.G_pre_monitors = {}
self.G_post_monitors = {}
self.G_pre_monitors.update(
((var,
RecentStateMonitor(G_pre,
vars_pre_ind[var],
duration=(C._max_delay + 1) *
C.target.clock.dt,
clock=G_pre.clock)) for var in vars_pre))
self.G_post_monitors.update(
((var,
RecentStateMonitor(
G_post,
vars_post_ind[var],
duration=(C._max_delay + 1) * C.target.clock.dt,
clock=G_post.clock)) for var in vars_post))
self.contained_objects += self.G_pre_monitors.values()
self.contained_objects += self.G_post_monitors.values()
prevars_dict_delayed = dict(
(k, self.G_pre_monitors[k]) for k in prevars_dict.keys())
postvars_dict_delayed = dict(
(k, self.G_post_monitors[k]) for k in postvars_dict.keys())
precode_immediate = iterate_over_spikes(
'_j', '_spikes', (load_required_variables(
'_j', prevars_dict), transform_code(per_neuron_pre)))
precode_delayed = iterate_over_spikes(
'_j', '_spikes',
iterate_over_row('_k',
'w',
C.W,
'_j',
extravars={'_delay': C.delayvec},
code=(ConnectionCode(
'double _t_past = _max_delay-_delay;',
vars={'_max_delay': float(max_delay)}),
load_required_variables_pastvalue(
'_k', '_t_past',
postvars_dict_delayed),
transform_code(per_synapse_pre),
ConnectionCode(clipcode))))
postcode = iterate_over_spikes(
'_j', '_spikes',
(load_required_variables(
'_j', postvars_dict), transform_code(per_neuron_post),
iterate_over_col('_i',
'w',
C.W,
'_j',
extravars={'_delay': C.delayvec},
code=(load_required_variables_pastvalue(
'_i', '_delay', prevars_dict_delayed),
transform_code(per_synapse_post),
ConnectionCode(clipcode)))))
log_debug('brian.experimental.c_stdp',
'CSTDP Pre code (immediate):\n' + str(precode_immediate))
log_debug('brian.experimental.c_stdp',
'CSTDP Pre code (delayed):\n' + str(precode_delayed))
log_debug('brian.experimental.c_stdp',
'CSTDP Post code:\n' + str(postcode))
pre_updater_immediate = SpikeMonitor(C.source,
function=precode_immediate)
pre_updater_delayed = SpikeMonitor(C.source,
function=precode_delayed,
delay=max_delay)
post_updater = SpikeMonitor(C.target, function=postcode)
updaters = [
pre_updater_immediate, pre_updater_delayed, post_updater
]
self.contained_objects += updaters
def __setitem__(self, key, value):
'''
Creates new synapses.
Synapse indexes are created such that synapses with the same presynaptic neuron
and delay have contiguous indexes.
Caution:
1) there is no deletion
2) synapses are added, not replaced (e.g. S[1,2]=True;S[1,2]=True creates 2 synapses)
TODO:
* S[:,:]=array (boolean or int)
'''
if self._iscompressed:
raise AttributeError,"Synapses cannot be added after they have been run"
if not isinstance(key, tuple): # we should check that number of elements is 2 as well
raise AttributeError,'Synapses behave as 2-D objects'
pre,post=key # pre and post indexes (can be slices)
'''
Each of these sets of statements creates:
* synapses_pre: a mapping from presynaptic neuron to synapse indexes
* synapses_post: same
* presynaptic: an array of presynaptic neuron indexes (synapse->pre)
* postsynaptic: same
'''
pre_slice = self.presynaptic_indexes(pre)
post_slice = self.postsynaptic_indexes(post)
# Bound checks
if pre_slice[-1]>=len(self.source):
raise ValueError('Presynaptic index %d greater than number of '\
'presynaptic neurons (%d)'
% (pre_slice[-1], len(self.source)))
if post_slice[-1]>=len(self.target):
raise ValueError('Postsynaptic index %d greater than number of '\
'postsynaptic neurons (%d)'
% (post_slice[-1], len(self.target)))
if isinstance(value,float):
self.connect_random(pre,post,value)
return
elif isinstance(value, (int, bool)): # ex. S[1,7]=True
# Simple case, either one or multiple synapses between different neurons
if value is False:
raise ValueError('Synapses cannot be deleted')
elif value is True:
nsynapses = 1
else:
nsynapses = value
postsynaptic,presynaptic=np.meshgrid(post_slice,pre_slice) # synapse -> pre, synapse -> post
# Flatten
presynaptic.shape=(presynaptic.size,)
postsynaptic.shape=(postsynaptic.size,)
# pre,post -> synapse index, relative to last synapse
# (that's a complex vectorised one!)
synapses_pre=np.arange(len(presynaptic)).reshape((len(pre_slice),len(post_slice)))
synapses_post=np.ones((len(post_slice),1),dtype=int)*np.arange(0,len(presynaptic),len(post_slice))+\
np.arange(len(post_slice)).reshape((len(post_slice),1))
# Repeat
if nsynapses>1:
synapses_pre=np.hstack([synapses_pre+k*len(presynaptic) for k in range(nsynapses)]) # could be vectorised
synapses_post=np.hstack([synapses_post+k*len(presynaptic) for k in range(nsynapses)]) # could be vectorised
presynaptic=np.tile(presynaptic,nsynapses)
postsynaptic=np.tile(postsynaptic,nsynapses)
# Make sure the type is correct
synapses_pre=np.array(synapses_pre,dtype=self.synapses_pre[0].dtype)
synapses_post=np.array(synapses_post,dtype=self.synapses_post[0].dtype)
# Turn into dictionaries
synapses_pre=dict(zip(pre_slice,synapses_pre))
synapses_post=dict(zip(post_slice,synapses_post))
elif isinstance(value,str): # string code assignment
# For subgroups, origin of i and j are shifted to subgroup origin
if isinstance(pre,NeuronGroup):
pre_shift=pre_slice[0]
else:
pre_shift=0
if isinstance(post,NeuronGroup):
post_shift=post_slice[0]
else:
post_shift=0
code = re.sub(r'\b' + 'rand\(\)', 'rand(n)', value) # replacing rand()
code = re.sub(r'\b' + 'randn\(\)', 'randn(n)', code) # replacing randn()
_namespace = namespace(value, level=1)
_namespace.update({'j' : post_slice-post_shift,
'n' : len(post_slice),
'rand': np.random.rand,
'randn': np.random.randn})
# try: # Vectorise over all indexes: not faster!
# post,pre=np.meshgrid(post_slice-post_shift,pre_slice-pre_shift)
# pre=pre.flatten()
# post=post.flatten()
# _namespace['i']=array(pre,dtype=self.presynaptic.dtype)
# _namespace['j']=array(post,dtype=self.postsynaptic.dtype)
# _namespace['n']=len(post)
# result = eval(code, _namespace) # mask on synapses
# if result.dtype==float: # random number generation
# result=rand(len(post))<result
# indexes=result.nonzero()[0]
# presynaptic=pre[indexes]
# postsynaptic=post[indexes]
# dtype=self.synapses_pre[0].dtype
# synapses_pre={}
# nsynapses=0
# for i in pre_slice:
# n=sum(result[i*len(post_slice):(i+1)*len(post_slice)])
# synapses_pre[i]=array(nsynapses+np.arange(n),dtype=dtype)
# nsynapses+=n
# except MemoryError: # If not possible, vectorise over postsynaptic indexes
# log_info("synapses","Construction of synapses cannot be fully vectorised (too big)")
#del pre
#del post
#_namespace['i']=None
#_namespace['j']=post_slice-post_shift
#_namespace['n']=len(post_slice)
synapses_pre={}
nsynapses=0
presynaptic,postsynaptic=[],[]
for i in pre_slice:
_namespace['i']=i-pre_shift # maybe an array rather than a scalar?
result = eval(code, _namespace) # mask on synapses
if result.dtype==float: # random number generation
result=rand(len(post_slice))<result
indexes=result.nonzero()[0]
n=len(indexes)
synapses_pre[i]=np.array(nsynapses+np.arange(n),dtype=self.synapses_pre[0].dtype)
presynaptic.append(i*np.ones(n,dtype=int))
postsynaptic.append(post_slice[indexes])
nsynapses+=n
# Make sure the type is correct
presynaptic=np.array(np.hstack(presynaptic),dtype=self.presynaptic.dtype)
postsynaptic=np.array(np.hstack(postsynaptic),dtype=self.postsynaptic.dtype)
synapses_post=None
elif isinstance(value, np.ndarray):
raise NotImplementedError
nsynapses = np.array(value, dtype = int)
# Now create the synapses
self.create_synapses(presynaptic,postsynaptic,synapses_pre,synapses_post)
def generate_code(self,code,level,direct=False,code_namespace=None):
'''
Generates pre and post code.
``code''
The code as a string.
``level''
The namespace level in which the code is executed.
``direct=False''
If True, the code is generated assuming that
postsynaptic variables are not modified. This makes the
code faster.
``code_namespace''
Additional namespace (highest priority)
TODO:
* include static variables (substitution)
* have a list of variable names
'''
# Handle multi-line pre, post equations and multi-statement equations separated by ;
# (this should probably be factored)
if '\n' in code:
code = flattened_docstring(code)
elif ';' in code:
code = '\n'.join([line.strip() for line in code.split(';')])
# Create namespaces
_namespace = namespace(code, level = level + 1)
if code_namespace is not None:
_namespace.update(code_namespace)
_namespace['target'] = self.target # maybe we could save one indirection here
_namespace['unique'] = np.unique
_namespace['nonzero'] = np.nonzero
_namespace['empty'] = np.empty
_namespace['logical_not'] = np.logical_not
_namespace['not_equal'] = np.not_equal
_namespace['take'] = np.take
_namespace['extract'] = np.extract
_namespace['add'] = np.add
_namespace['hstack'] = np.hstack
code = re.sub(r'\b' + 'rand\(\)', 'rand(n)', code)
code = re.sub(r'\b' + 'randn\(\)', 'randn(n)', code)
# Generate the code
def update_code(code, indices, postinds):
res = code
# given the synapse indices, write the update code,
# this is here because in the code we generate we need to write this twice (because of the multiple presyn spikes for the same postsyn neuron problem)
# Replace synaptic variables by their value
for var in self.var_index: # static variables are not included here
if isinstance(var, str):
res = re.sub(r'\b' + var + r'\b', var + '['+indices+']', res) # synaptic variable, indexed by the synapse number
# Replace postsynaptic variables by their value
for postsyn_var in self.target.var_index: # static variables are not included here
if isinstance(postsyn_var, str):
#res = re.sub(r'\b' + postsyn_var + r'_post\b', 'target.' + postsyn_var + '['+postinds+']', res)# postsyn variable, indexed by post syn neuron numbers
#res = re.sub(r'\b' + postsyn_var + r'\b', 'target.' + postsyn_var + '['+postinds+']', res)# postsyn variable, indexed by post syn neuron numbers
res = re.sub(r'\b' + postsyn_var + r'_post\b', '_target_' + postsyn_var + '['+postinds+']', res)# postsyn variable, indexed by post syn neuron numbers
res = re.sub(r'\b' + postsyn_var + r'\b', '_target_' + postsyn_var + '['+postinds+']', res)# postsyn variable, indexed by post syn neuron numbers
_namespace['_target_' + postsyn_var] = self.target.state_(postsyn_var)
# Replace presynaptic variables by their value
for presyn_var in self.source.var_index: # static variables are not included here
if isinstance(presyn_var, str):
#res = re.sub(r'\b' + presyn_var + r'_pre\b', 'source.' + presyn_var + '[_pre['+indices+']]', res)# postsyn variable, indexed by post syn neuron numbers
res = re.sub(r'\b' + presyn_var + r'_pre\b', '_source_' + presyn_var + '[_pre['+indices+']]', res)# postsyn variable, indexed by post syn neuron numbers
_namespace['_source_' + presyn_var] = self.source.state_(presyn_var)
# Replace n by number of synapses being updated
res = re.sub(r'\bn\b','len('+indices+')', res)
return res
if direct: # direct update code, not caring about multiple accesses to postsynaptic variables
code_str = '_post_neurons = _post[_synapses]\n'+update_code(code, '_synapses', '_post_neurons') + "\n"
else:
algo = 3
if algo==0:
## Old version using numpy's unique()
code_str = "_post_neurons = _post[_synapses]\n" # not necessary to do a copy because _synapses is not a slice
code_str += "_u, _i = unique(_post_neurons, return_index = True)\n"
#code_str += update_code(code, '_synapses[_i]', '_u') + "\n"
code_str += update_code(code, '_synapses[_i]', '_post[_synapses[_i]]') + "\n"
code_str += "if len(_u) < len(_post_neurons):\n"
code_str += " _post_neurons[_i] = -1\n"
code_str += " while (len(_u) < len(_post_neurons)) & (_post_neurons>-1).any():\n" # !! the any() is time consuming (len(u)>=1??)
#code_str += " while (len(_u) < len(_post_neurons)) & (len(_u)>1):\n" # !! the any() is time consuming (len(u)>=1??)
code_str += " _u, _i = unique(_post_neurons, return_index = True)\n"
code_str += indent(update_code(code, '_synapses[_i[1:]]', '_post[_synapses[_i[1:]]]'),2) + "\n"
code_str += " _post_neurons[_i[1:]] = -1 \n"
elif algo==1:
code_str = "_post_neurons = _post[_synapses]\n" # not necessary to do a copy because _synapses is not a slice
code_str += "_perm = _post_neurons.argsort()\n"
code_str += "_aux = _post_neurons[_perm]\n"
code_str += "_flag = empty(len(_aux) + 1, dtype = bool)\n"
code_str += "_flag[0] = _flag[-1] = True\n"
code_str += "not_equal(_aux[1:], _aux[:-1], _flag[1:-1])\n"
code_str += "_F = _flag.nonzero()[0][:-1]\n"
code_str += "logical_not(_flag, _flag)\n"
code_str += "while len(_F):\n"
code_str += " _u = _aux[_F]\n"
code_str += " _i = _perm[_F]\n"
code_str += indent(update_code(code, '_synapses[_i]', '_u'), 1) + "\n"
code_str += " _F += 1\n"
code_str += " _F = _F[_flag[_F]]\n"
elif algo==2:
code_str = '''
_post_neurons = _post.data.take(_synapses)
_perm = _post_neurons.argsort()
_aux = _post_neurons.take(_perm)
_flag = empty(len(_aux)+1, dtype=bool)
_flag[0] = _flag[-1] = 1
not_equal(_aux[1:], _aux[:-1], _flag[1:-1])
if 0:#_flag.sum()==len(_aux)+1:
%(code1)s
else:
_F = _flag.nonzero()[0][:-1]
logical_not(_flag, _flag)
while len(_F):
_u = _aux.take(_F)
_i = _perm.take(_F)
%(code2)s
_F += 1
_F = extract(_flag.take(_F), _F)
'''
code_str = flattened_docstring(code_str) % {'code1': indent(update_code(code, '_synapses','_post_neurons'), 1),
'code2': indent(update_code(code, '_synapses[_i]', '_u'), 2)}
elif algo==3:
code_str = '''
_post_neurons = _post.data.take(_synapses)
_perm = _post_neurons.argsort()
_aux = _post_neurons.take(_perm)
_flag = empty(len(_aux)+1, dtype=bool)
_flag[0] = _flag[-1] = 1
not_equal(_aux[1:], _aux[:-1], _flag[1:-1])
_F = _flag.nonzero()[0][:-1]
logical_not(_flag, _flag)
while len(_F):
_u = _aux.take(_F)
_i = _perm.take(_F)
%(code)s
_F += 1
_F = extract(_flag.take(_F), _F)
'''
code_str = flattened_docstring(code_str) % {'code': indent(update_code(code, '_synapses[_i]', '_u'), 1)}
elif algo==4:
code_str = '''
_post_neurons = _post[_synapses]
_perm = _post_neurons.argsort()
_aux = _post_neurons[_perm]
_flag = empty(len(_aux)+1, dtype=bool)
_flag[0] = _flag[-1] = 1
not_equal(_aux[1:], _aux[:-1], _flag[1:-1])
_F = _flag.nonzero()[0][:-1]
logical_not(_flag, _flag)
while len(_F):
_u = _aux[_F]
_i = _perm[_F]
%(code)s
_F += 1
_F = _F[_flag[_F]]
'''
code_str = flattened_docstring(code_str) % {'code': indent(update_code(code, '_synapses[_i]', '_u'), 1)}
# print code_str
log_debug('brian.synapses', '\nCODE:\n'+code_str)
# Compile
compiled_code = compile(code_str, "Synaptic code", "exec")
_namespace['_original_code_string'] = code_str
return compiled_code,_namespace
def __init__(self, group, inputcode, language, level=0):
inputcode = inputcode.strip()
self.namespace = namespace(inputcode, level=level+1)
self.inputcode = inputcode
self.language = language
self.prepared = False
P = group
ns = self.namespace
self.inputcode = freeze_with_equations(self.inputcode, P._eqs, ns)
block = make_threshold_block(P, self.inputcode, self.language)
symbols = get_neuron_group_symbols(P, self.language)
symbols['_neuron_index'] = SliceIndex('_neuron_index',
'0',
'_num_neurons',
self.language,
all=True)
if self.language.name=='c':
symbols['_numspikes'] = NumSpikesSymbol('_numspikes',
self.language)
if self.language.name=='gpu':
_arr_spiked_bool = zeros(len(P)+1, dtype=int32)
symbols['_spiked'] = ArraySymbol(_arr_spiked_bool,
'_spiked',
self.language,
index='_neuron_index',
array_name='_arr_spiked_bool',
)
self._spiked_symbol = symbols['_spiked']
self._arr_spiked_bool = _arr_spiked_bool
code = self.code = block.generate('threshold', self.language,
symbols)
log_info('brian.codegen2.CodeGenThreshold', 'CODE:\n'+self.code.code_str)
log_info('brian.codegen2.CodeGenThreshold', 'KEYS:\n'+str(ns.keys()))
ns = self.code.namespace
ns['t'] = 1.0 # dummy value
ns['dt'] = P.clock._dt
ns['_num_neurons'] = len(P)
if self.language.name=='python':
def threshold_func(P):
code()
return ns['_spikes_bool'].nonzero()[0]
elif self.language.name=='c':
ns['_spikes'] = zeros(len(P), dtype=int)
def threshold_func(P):
code()
return ns['_spikes'][:ns['_arr__numspikes'][0]]
elif self.language.name=='gpu':
ns['_arr_spiked_bool'] = _arr_spiked_bool
ns['_num_gpu_indices'] = len(P)
# TODO: this threshold func should do nothing on GPU unless
# we want to force sync, or alternatively we can do a
# compaction on the GPU and then return that
compactor = GPUCompactor(len(P), index_dtype=int32)
device_syms = code.gpu_man.mem_man.device
def threshold_func(P):
code()
return compactor(device_syms['_arr_spiked_bool'])
#if not language.force_sync:
# code.gpu_man.copy_to_host('_arr_spiked_bool')
#return ns['_arr_spiked_bool'].nonzero()[0]
self.threshold_func = threshold_func
def select_threshold(expr, eqs, level=0):
'''
Automatically selects the appropriate Threshold object from a string.
Matches the following patterns:
var_name > or >= const : Threshold
var_name > or >= var_name : VariableThreshold
others : StringThreshold
'''
global CThreshold, PythonThreshold
use_codegen = (get_global_preference('usecodegen') and
get_global_preference('usecodegenthreshold'))
use_weave = (get_global_preference('useweave') and
get_global_preference('usecodegenweave'))
if use_codegen:
if CThreshold is None:
from brian.experimental.codegen.threshold import (CThreshold,
PythonThreshold)
if use_weave:
log_warn('brian.threshold', 'Using codegen CThreshold')
return CThreshold(expr, level=level + 1)
else:
log_warn('brian.threshold', 'Using codegen PythonThreshold')
return PythonThreshold(expr, level=level + 1)
# plan:
# - see if it matches A > B or A >= B, if not select StringThreshold
# - check if A, B both match diffeq variable names, and if so
# select VariableThreshold
# - check that A is a variable name, if not select StringThreshold
# - extract all the identifiers from B, and if none of them are
# callable, assume it is a constant, try to eval it and then use
# Threshold. If not, or if eval fails, use StringThreshold.
# This misses the case of e.g. V>10*mV*exp(1) because exp will be
# callable, but in general a callable means that it could be
# non-constant.
expr = expr.strip()
eqs.prepare()
ns = namespace(expr, level=level + 1)
s = re.search(r'^\s*(\w+)\s*>=?(.+)', expr)
if not s:
return StringThreshold(expr, level=level + 1)
A = s.group(1)
B = s.group(2).strip()
if A not in eqs._diffeq_names:
return StringThreshold(expr, level=level + 1)
if B in eqs._diffeq_names:
return VariableThreshold(B, A)
try:
vars = get_identifiers(B)
except SyntaxError:
return StringThreshold(expr, level=level + 1)
all_vars = eqs._eq_names + eqs._diffeq_names + eqs._alias.keys() + ['t']
for v in vars:
if v not in ns or v in all_vars or callable(ns[v]):
return StringThreshold(expr, level=level + 1)
try:
val = eval(B, ns)
except:
return StringThreshold(expr, level=level + 1)
return Threshold(val, A)
def __init__(self, inputcode, language, level=0):
self._ns, unknowns = namespace(inputcode, level=level+1, return_unknowns=True)
self._inputcode = inputcode
self._language = language
self._prepared = False
def __init__(self, C, eqs, pre, post, wmin=0, wmax=Inf, level=0,
clock=None, delay_pre=None, delay_post=None):
NetworkOperation.__init__(self, lambda:None, clock=clock)
C.compress()
# Convert to equations object
if isinstance(eqs, Equations):
eqs_obj = eqs
else:
eqs_obj = Equations(eqs, level=level + 1)
# handle multi-line pre, post equations and multi-statement equations separated by ;
if '\n' in pre:
pre = flattened_docstring(pre)
elif ';' in pre:
pre = '\n'.join([line.strip() for line in pre.split(';')])
if '\n' in post:
post = flattened_docstring(post)
elif ';' in post:
post = '\n'.join([line.strip() for line in post.split(';')])
# Check units
eqs_obj.compile_functions()
eqs_obj.check_units()
# Get variable names
vars = eqs_obj._diffeq_names
# Find which ones are directly modified (e.g. regular expression matching; careful with comments)
vars_pre = [var for var in vars if var in modified_variables(pre)]
vars_post = [var for var in vars if var in modified_variables(post)]
# additional dependencies are used to ensure that if there are multiple
# pre/post separated equations they are grouped together as one
additional_deps = ['__pre_deps='+'+'.join(vars_pre),
'__post_deps='+'+'.join(vars_post)]
separated_equations = separate_equations(eqs_obj, additional_deps)
if not len(separated_equations) == 2:
print separated_equations
raise ValueError('Equations should separate into pre and postsynaptic variables.')
sep_pre, sep_post = separated_equations
for v in vars_pre:
if v in sep_post._diffeq_names:
sep_pre, sep_post = sep_post, sep_pre
break
index_pre = [i for i in range(len(vars)) if vars[i] in vars_pre or vars[i] in sep_pre._diffeq_names]
index_post = [i for i in range(len(vars)) if vars[i] in vars_post or vars[i] in sep_post._diffeq_names]
vars_pre = array(vars)[index_pre].tolist()
vars_post = array(vars)[index_post].tolist()
# Check pre/post consistency
shared_vars = set(vars_pre).intersection(vars_post)
if shared_vars != set([]):
raise Exception, str(list(shared_vars)) + " are both presynaptic and postsynaptic!"
# Substitute equations/aliases into pre/post code
def substitute_eqs(code):
for name in sep_pre._eq_names[-1::-1]+sep_post._eq_names[-1::-1]: # reverse order, as in equations.py
if name in sep_pre._eq_names:
expr = sep_pre._string[name]
else:
expr = sep_post._string[name]
code = re.sub("\\b" + name + "\\b", '(' + expr + ')', code)
return code
pre = substitute_eqs(pre)
post = substitute_eqs(post)
# Create namespaces for pre and post codes
pre_namespace = namespace(pre, level=level + 1)
post_namespace = namespace(post, level=level + 1)
def splitcode(incode):
num_perneuron = num_persynapse = 0
reordering_warning = False
incode_lines = [line.strip() for line in incode.split('\n') if line.strip()]
per_neuron_lines = []
per_synapse_lines = []
for line in incode_lines:
if not line.strip(): continue
m = re.search(r'\bw\b\s*[^><=]?=', line) # lines of the form w = ..., w *= ..., etc.
if m:
num_persynapse += 1
per_synapse_lines.append(line)
else:
num_perneuron += 1
if num_persynapse!=0 and not reordering_warning:
log_warn('brian.experimental.cstdp', 'STDP operations are being re-ordered, results may be wrong.')
reordering_warning = True
per_neuron_lines.append(line)
return per_neuron_lines, per_synapse_lines
per_neuron_pre, per_synapse_pre = splitcode(pre)
per_neuron_post, per_synapse_post = splitcode(post)
all_vars = vars_pre + vars_post + ['w']
per_neuron_pre = [c_single_statement(freeze(line, all_vars, pre_namespace)) for line in per_neuron_pre]
per_neuron_post = [c_single_statement(freeze(line, all_vars, post_namespace)) for line in per_neuron_post]
per_synapse_pre = [c_single_statement(freeze(line, all_vars, pre_namespace)) for line in per_synapse_pre]
per_synapse_post = [c_single_statement(freeze(line, all_vars, post_namespace)) for line in per_synapse_post]
per_neuron_pre = '\n'.join(per_neuron_pre)
per_neuron_post = '\n'.join(per_neuron_post)
per_synapse_pre = '\n'.join(per_synapse_pre)
per_synapse_post = '\n'.join(per_synapse_post)
# Neuron groups
G_pre = NeuronGroup(len(C.source), model=sep_pre, clock=self.clock)
G_post = NeuronGroup(len(C.target), model=sep_post, clock=self.clock)
G_pre._S[:] = 0
G_post._S[:] = 0
self.pre_group = G_pre
self.post_group = G_post
var_group = {}
for i, v in enumerate(vars_pre):
var_group[v] = G_pre
for i, v in enumerate(vars_post):
var_group[v] = G_post
self.var_group = var_group
self.contained_objects += [G_pre, G_post]
vars_pre_ind = {}
for i, var in enumerate(vars_pre):
vars_pre_ind[var] = i
vars_post_ind = {}
for i, var in enumerate(vars_post):
vars_post_ind[var] = i
prevars_dict = dict((k, G_pre.state(k)) for k in vars_pre)
postvars_dict = dict((k, G_post.state(k)) for k in vars_post)
clipcode = ''
if isfinite(wmin):
clipcode += 'if(w<%wmin%) w = %wmin%;\n'.replace('%wmin%', repr(float(wmin)))
if isfinite(wmax):
clipcode += 'if(w>%wmax%) w = %wmax%;\n'.replace('%wmax%', repr(float(wmax)))
if not isinstance(C, DelayConnection):
precode = iterate_over_spikes('_j', '_spikes',
(load_required_variables('_j', prevars_dict),
transform_code(per_neuron_pre),
iterate_over_row('_k', 'w', C.W, '_j',
(load_required_variables('_k', postvars_dict),
transform_code(per_synapse_pre),
ConnectionCode(clipcode)))))
postcode = iterate_over_spikes('_j', '_spikes',
(load_required_variables('_j', postvars_dict),
transform_code(per_neuron_post),
iterate_over_col('_i', 'w', C.W, '_j',
(load_required_variables('_i', prevars_dict),
transform_code(per_synapse_post),
ConnectionCode(clipcode)))))
log_debug('brian.experimental.c_stdp', 'CSTDP Pre code:\n' + str(precode))
log_debug('brian.experimental.c_stdp', 'CSTDP Post code:\n' + str(postcode))
connection_delay = C.delay * C.source.clock.dt
if (delay_pre is None) and (delay_post is None): # same delays as the Connnection C
delay_pre = connection_delay
delay_post = 0 * ms
elif delay_pre is None:
delay_pre = connection_delay - delay_post
if delay_pre < 0 * ms: raise AttributeError, "Postsynaptic delay is too large"
elif delay_post is None:
delay_post = connection_delay - delay_pre
if delay_post < 0 * ms: raise AttributeError, "Postsynaptic delay is too large"
# create forward and backward Connection objects or SpikeMonitor objects
pre_updater = SpikeMonitor(C.source, function=precode, delay=delay_pre)
post_updater = SpikeMonitor(C.target, function=postcode, delay=delay_post)
updaters = [pre_updater, post_updater]
self.contained_objects += [pre_updater, post_updater]
else:
if delay_pre is not None or delay_post is not None:
raise ValueError("Must use delay_pre=delay_post=None for the moment.")
max_delay = C._max_delay * C.target.clock.dt
# Ensure that the source and target neuron spikes are kept for at least the
# DelayConnection's maximum delay
C.source.set_max_delay(max_delay)
C.target.set_max_delay(max_delay)
self.G_pre_monitors = {}
self.G_post_monitors = {}
self.G_pre_monitors.update(((var, RecentStateMonitor(G_pre, vars_pre_ind[var], duration=(C._max_delay + 1) * C.target.clock.dt, clock=G_pre.clock)) for var in vars_pre))
self.G_post_monitors.update(((var, RecentStateMonitor(G_post, vars_post_ind[var], duration=(C._max_delay + 1) * C.target.clock.dt, clock=G_post.clock)) for var in vars_post))
self.contained_objects += self.G_pre_monitors.values()
self.contained_objects += self.G_post_monitors.values()
prevars_dict_delayed = dict((k, self.G_pre_monitors[k]) for k in prevars_dict.keys())
postvars_dict_delayed = dict((k, self.G_post_monitors[k]) for k in postvars_dict.keys())
precode_immediate = iterate_over_spikes('_j', '_spikes',
(load_required_variables('_j', prevars_dict),
transform_code(per_neuron_pre)))
precode_delayed = iterate_over_spikes('_j', '_spikes',
iterate_over_row('_k', 'w', C.W, '_j', extravars={'_delay':C.delayvec},
code=(
ConnectionCode('double _t_past = _max_delay-_delay;', vars={'_max_delay':float(max_delay)}),
load_required_variables_pastvalue('_k', '_t_past', postvars_dict_delayed),
transform_code(per_synapse_pre),
ConnectionCode(clipcode))))
postcode = iterate_over_spikes('_j', '_spikes',
(load_required_variables('_j', postvars_dict),
transform_code(per_neuron_post),
iterate_over_col('_i', 'w', C.W, '_j', extravars={'_delay':C.delayvec},
code=(
load_required_variables_pastvalue('_i', '_delay', prevars_dict_delayed),
transform_code(per_synapse_post),
ConnectionCode(clipcode)))))
log_debug('brian.experimental.c_stdp', 'CSTDP Pre code (immediate):\n' + str(precode_immediate))
log_debug('brian.experimental.c_stdp', 'CSTDP Pre code (delayed):\n' + str(precode_delayed))
log_debug('brian.experimental.c_stdp', 'CSTDP Post code:\n' + str(postcode))
pre_updater_immediate = SpikeMonitor(C.source, function=precode_immediate)
pre_updater_delayed = SpikeMonitor(C.source, function=precode_delayed, delay=max_delay)
post_updater = SpikeMonitor(C.target, function=postcode)
updaters = [pre_updater_immediate, pre_updater_delayed, post_updater]
self.contained_objects += updaters
