def spy(P,i=None,file=None,scale=None):
"""Generates sparsity plot using Pylab"""
if type(P) is spmatrix:
V = chompack.symmetrize(chompack.tril(P))
n = V.size[0]
else:
if not P._A: raise AttributeError, "SDP data missing"
n = +P.n;
if i == None: V = chompack.symmetrize(P.V)
elif i>=0 and i<=P.m and P._A:
r = P._A.CCS[1][P._A.CCS[0][i]:P._A.CCS[0][i+1]]
if type(r) is int: I = [r%n]; J = [r/n]
else: I,J = misc.ind2sub(n,r)
V = chompack.symmetrize(spmatrix(0.,I,J,(n,n)))
else: raise ValueError, "index out of range"
from math import floor
msize = max(1,int(floor(100./n)))
if file==None: pylab.ion()
else: pylab.ioff()
f = pylab.figure(figsize=(6,6)); f.clf()
if scale is None: scale = 1.0
I = V.I*scale+1; J = (n-V.J)*scale
p = pylab.plot(I,J, 's', linewidth = 1, hold = 'False')
pylab.setp(p, markersize = msize, markerfacecolor = 'k')
g = pylab.gca()
pylab.axis([0.5,n*scale+0.5,0.5,n*scale+0.5])
g.set_aspect('equal')
locs,labels = pylab.yticks()
locs = locs[locs<=n*scale]; locs = locs[locs>=1]
pylab.yticks(locs[::-1]-(locs[-1]-n*scale-1)-locs[0],
[str(int(loc)) for loc in locs])
if file: pylab.savefig(file)
def get_A(self,i=None):
"""Returns A if i is None, otherwise returns Ai as spmatrix"""
if i==None and self._A: return self._A
elif i>=0 and i<=self.m and self._A:
r = self._A.CCS[1][self._A.CCS[0][i]:self._A.CCS[0][i+1]]
v = self._A.CCS[2][self._A.CCS[0][i]:self._A.CCS[0][i+1]]
if isinstance(v,float): I = [r/self.n]; J = [r%self.n]
else: I,J = misc.ind2sub(self.n,r)
return spmatrix(v,I,J,(self.n,self.n))
elif self._A: raise ValueError("index is out of range")
else: raise AttributeError("SDP object has not been initialized")
def get_A(self, i=None):
"""Returns A if i is None, otherwise returns Ai as spmatrix"""
if i == None and self._A: return self._A
elif i >= 0 and i <= self.m and self._A:
r = self._A.CCS[1][self._A.CCS[0][i]:self._A.CCS[0][i + 1]]
v = self._A.CCS[2][self._A.CCS[0][i]:self._A.CCS[0][i + 1]]
if isinstance(v, float):
I = [r / self.n]
J = [r % self.n]
else:
I, J = misc.ind2sub(self.n, r)
return spmatrix(v, I, J, (self.n, self.n))
elif self._A:
raise ValueError, "index is out of range"
else:
raise AttributeError, "SDP object has not been initialized"
def V(self):
"""Sparsity pattern (CVXOPT spmatrix)"""
I,J = misc.ind2sub(self.n,self.I)
return spmatrix(0.,I,J,(self.n,self.n))
def V(self):
"""Sparsity pattern (CVXOPT spmatrix)"""
I, J = misc.ind2sub(self.n, self.I)
return spmatrix(0., I, J, (self.n, self.n))