def set_data(self, x, y, A):
x = asarray(x).astype(Float32)
y = asarray(y).astype(Float32)
A = asarray(A)
if len(x.shape) != 1 or len(y.shape) != 1\
or A.shape[0:2] != (y.shape[0], x.shape[0]):
raise TypeError("Axes don't match array shape")
if len(A.shape) not in [2, 3]:
raise TypeError("Can only plot 2D or 3D data")
if len(A.shape) == 3 and A.shape[2] not in [1, 3, 4]:
raise TypeError("3D arrays must have three (RGB) or four (RGBA) color components")
if len(A.shape) == 3 and A.shape[2] == 1:
A.shape = A.shape[0:2]
if len(A.shape) == 2:
if typecode(A) != UInt8:
A = (self.cmap(self.norm(A))*255).astype(UInt8)
else:
A = repeat(A[:,:,NewAxis], 4, 2)
A[:,:,3] = 255
else:
if typecode(A) != UInt8:
A = (255*A).astype(UInt8)
if A.shape[2] == 3:
B = zeros(tuple(list(A.shape[0:2]) + [4]), UInt8)
B[:,:,0:3] = A
B[:,:,3] = 255
A = B
self._A = A
self._Ax = x
self._Ay = y
self._imcache = None
def dist_point_to_segment(p, s0, s1):
"""
get the distance of a point to a segment.
p, s0, s1 are xy sequences
This algorithm from
http://softsurfer.com/Archive/algorithm_0102/algorithm_0102.htm#Distance%20to%20Ray%20or%20Segment
"""
p = asarray(p, Float)
s0 = asarray(s0, Float)
s1 = asarray(s1, Float)
v = s1 - s0
w = p - s0
c1 = dot(w,v);
if ( c1 <= 0 ):
return dist(p, s0);
c2 = dot(v,v)
if ( c2 <= c1 ):
return dist(p, s1);
b = c1 / c2
pb = s0 + b * v;
return dist(p, pb)
def set_data(self, *args):
"""
Set the x and y data
ACCEPTS: (array xdata, array ydata)
"""
if len(args)==1:
x, y = args[0]
else:
x, y = args
try: del self._xc, self._yc
except AttributeError: pass
self._x = asarray(x, Float)
self._y = asarray(y, Float)
if len(self._x.shape)>1: self._x = ravel(self._x)
if len(self._y.shape)>1: self._y = ravel(self._y)
if len(self._y)==1 and len(self._x)>1:
self._y = self._y*ones(self._x.shape, Float)
if len(self._x) != len(self._y):
raise RuntimeError('xdata and ydata must be the same length')
if self._useDataClipping: self._xsorted = self._is_sorted(self._x)
self._logcache = None
def _update_x_y_logcache(self):
# check cache
need_update = False
try:
for key, var_id in self._cache_inputs.iteritems():
if id(getattr(self, key)) != var_id:
need_update = True
break
except:
need_update = True
if not need_update:
return
# update cache
for key in self._cache_inputs.keys():
try:
self._cache_inputs[key] = id(getattr(self, key))
except:
pass
# make sure that result values exist and release
# previous values
self._cached__x = None
self._cached__y = None
self._cached__segments = None
self._cached__logcache = None
if self.is_unitsmgr_set():
unitsmgr = self.get_unitsmgr()
x, y = unitsmgr._convert_units((self._x_orig, self._xunits), (self._y_orig, self._yunits))
else:
x, y = (self._x_orig, self._y_orig)
x = ma.ravel(x)
y = ma.ravel(y)
if len(x) == 1 and len(y) > 1:
x = x * ones(y.shape, Float)
if len(y) == 1 and len(x) > 1:
y = y * ones(x.shape, Float)
if len(x) != len(y):
raise RuntimeError("xdata and ydata must be the same length")
mx = ma.getmask(x)
my = ma.getmask(y)
mask = ma.mask_or(mx, my)
if mask is not ma.nomask:
x = ma.masked_array(x, mask=mask).compressed()
y = ma.masked_array(y, mask=mask).compressed()
self._cached__segments = unmasked_index_ranges(mask)
else:
self._cached__segments = None
self._cached__x = asarray(x, Float)
self._cached__y = asarray(y, Float)
self._cached__logcache = None
def rk4(derivs, y0, t):
"""
Integrate 1D or ND system of ODEs from initial state y0 at sample
times t. derivs returns the derivative of the system and has the
signature
dy = derivs(yi, ti)
Example 1 :
## 2D system
# Numeric solution
def derivs6(x,t):
d1 = x[0] + 2*x[1]
d2 = -3*x[0] + 4*x[1]
return (d1, d2)
dt = 0.0005
t = arange(0.0, 2.0, dt)
y0 = (1,2)
yout = rk4(derivs6, y0, t)
Example 2:
## 1D system
alpha = 2
def derivs(x,t):
return -alpha*x + exp(-t)
y0 = 1
yout = rk4(derivs, y0, t)
"""
try: Ny = len(y0)
except TypeError:
yout = zeros( (len(t),), Float)
else:
yout = zeros( (len(t), Ny), Float)
yout[0] = y0
i = 0
for i in arange(len(t)-1):
thist = t[i]
dt = t[i+1] - thist
dt2 = dt/2.0
y0 = yout[i]
k1 = asarray(derivs(y0, thist))
k2 = asarray(derivs(y0 + dt2*k1, thist+dt2))
k3 = asarray(derivs(y0 + dt2*k2, thist+dt2))
k4 = asarray(derivs(y0 + dt*k3, thist+dt))
yout[i+1] = y0 + dt/6.0*(k1 + 2*k2 + 2*k3 + k4)
return yout
def draw_regpoly_collection(
self, clipbox, offsets, transOffset, verts, sizes,
facecolors, edgecolors, linewidths, antialiaseds):
"""
Draw a regular poly collection
offsets - is a sequence is x,y tuples
transOffset - maps this to display coords
verts - are the vertices of the regular polygon at the origin
sizes are the area of the circle that circumscribes the
polygon in points^2
facecolors and edgecolors are a sequence of RGBA tuples
linewidths are a sequence of linewidths
antialiaseds are a sequence of 0,1 integers whether to use aa
"""
gc = self.new_gc()
if clipbox is not None:
gc.set_clip_rectangle(clipbox.get_bounds())
xverts, yverts = zip(*verts)
xverts = asarray(xverts)
yverts = asarray(yverts)
Nface = len(facecolors)
Nedge = len(edgecolors)
Nlw = len(linewidths)
Naa = len(antialiaseds)
Nsizes = len(sizes)
for i, loc in enumerate(offsets):
xo,yo = transOffset.xy_tup(loc)
#print 'xo, yo', loc, (xo, yo)
scale = sizes[i % Nsizes]
thisxverts = scale*xverts + xo
thisyverts = scale*yverts + yo
#print 'xverts', xverts
rf,gf,bf,af = facecolors[i % Nface]
re,ge,be,ae = edgecolors[i % Nedge]
if af==0:
rgbFace = None
else:
rgbFace = rf,gf,bf
# the draw_poly interface can't handle separate alphas for
# edge and face so we'll just use
alpha = max(af,ae)
gc.set_foreground( (re,ge,be), isRGB=True)
gc.set_alpha( alpha )
gc.set_linewidth( linewidths[i % Nlw] )
gc.set_antialiased( antialiaseds[i % Naa] )
#print 'verts', zip(thisxverts, thisyverts)
self.draw_polygon(gc, rgbFace, zip(thisxverts, thisyverts))
def set_data(self, *args):
"""
Set the x and y data
ACCEPTS: (array xdata, array ydata)
"""
if len(args) == 1:
x, y = args[0]
else:
x, y = args
try:
del self._xc, self._yc
except AttributeError:
pass
self._masked_x = None
self._masked_y = None
mx = ma.getmask(x)
my = ma.getmask(y)
if mx is not None:
mx = ravel(mx)
self._masked_x = x
if my is not None:
my = ravel(my)
self._masked_y = y
mask = ma.mask_or(mx, my)
if mask is not None:
x = ma.masked_array(ma.ravel(x), mask=mask).compressed()
y = ma.masked_array(ma.ravel(y), mask=mask).compressed()
self._segments = unmasked_index_ranges(mask)
else:
self._segments = None
self._x = asarray(x, Float)
self._y = asarray(y, Float)
if len(self._x.shape) > 1:
self._x = ravel(self._x)
if len(self._y.shape) > 1:
self._y = ravel(self._y)
# What is the rationale for the following two lines?
# And why is there not a similar pair with _x and _y reversed?
if len(self._y) == 1 and len(self._x) > 1:
self._y = self._y * ones(self._x.shape, Float)
if len(self._x) != len(self._y):
raise RuntimeError("xdata and ydata must be the same length")
if self._useDataClipping:
self._xsorted = self._is_sorted(self._x)
self._logcache = None
def set_data(self, *args):
"""
Set the x and y data
ACCEPTS: (array xdata, array ydata)
"""
if len(args)==1:
x, y = args[0]
else:
x, y = args
self._x_orig = x
self._y_orig = y
if (self._xunits and hasattr(x, 'convert_to')):
x = x.convert_to(self._xunits).get_value()
if (hasattr(x, 'get_value')):
x = x.get_value()
if (self._yunits and hasattr(y, 'convert_to')):
y = y.convert_to(self._yunits).get_value()
if (hasattr(y, 'get_value')):
y = y.get_value()
x = ma.ravel(x)
y = ma.ravel(y)
if len(x)==1 and len(y)>1:
x = x * ones(y.shape, Float)
if len(y)==1 and len(x)>1:
y = y * ones(x.shape, Float)
if len(x) != len(y):
raise RuntimeError('xdata and ydata must be the same length')
mx = ma.getmask(x)
my = ma.getmask(y)
mask = ma.mask_or(mx, my)
if mask is not ma.nomask:
x = ma.masked_array(x, mask=mask).compressed()
y = ma.masked_array(y, mask=mask).compressed()
self._segments = unmasked_index_ranges(mask)
else:
self._segments = None
self._x = asarray(x, Float)
self._y = asarray(y, Float)
self._logcache = None
def epoch2num(e):
"""
convert an epoch or sequence of epochs to the new date format,
days since 0001
"""
spd = 24.*3600.
return 719163 + asarray(e)/spd
def _contour_args(self, filled, badmask, origin, extent, *args):
if filled: fn = 'contourf'
else: fn = 'contour'
Nargs = len(args)
if Nargs <= 2:
z = args[0]
x, y = self._initialize_x_y(z, origin, extent)
elif Nargs <=4:
x,y,z = self._check_xyz(args[:3])
else:
raise TypeError("Too many arguments to %s; see help(%s)" % (fn,fn))
z = asarray(z) # Convert to native array format if necessary.
if Nargs == 1 or Nargs == 3:
lev = self._autolev(z, 7, filled, badmask)
else: # 2 or 4 args
level_arg = args[-1]
if type(level_arg) == int:
lev = self._autolev(z, level_arg, filled, badmask)
elif iterable(level_arg) and len(shape(level_arg)) == 1:
lev = array([float(fl) for fl in level_arg])
else:
raise TypeError("Last %s arg must give levels; see help(%s)" % (fn,fn))
rx = ravel(x)
ry = ravel(y)
self.ax.set_xlim((min(rx), max(rx)))
self.ax.set_ylim((min(ry), max(ry)))
return (x, y, z, lev)
def __call__(self, value):
vmin = self.vmin
vmax = self.vmax
if type(value) in [IntType, FloatType]:
vtype = 'scalar'
val = array([value])
else:
vtype = 'array'
val = asarray(value)
# if both vmin is None and vmax is None, we'll automatically
# norm the data to vmin/vmax of the actual data, so the
# clipping step won't be needed.
if vmin is None and vmax is None:
needs_clipping = False
else:
needs_clipping = True
if vmin is None or vmax is None:
rval = ravel(val)
if vmin is None: vmin = amin(rval)
if vmax is None: vmax = amax(rval)
if vmin > vmax:
raise ValueError("minvalue must be less than or equal to maxvalue")
elif vmin==vmax:
return 0.*value
else:
if needs_clipping:
val = clip(val,vmin, vmax)
result = (1.0/(vmax-vmin))*(val-vmin)
if vtype == 'scalar':
result = result[0]
return result
def __init__(self,
dpi,
numsides,
rotation = 0 ,
sizes = (1,),
**kwargs):
"""
Draw a regular polygon with numsides. sizes gives the area of
the circle circumscribing the regular polygon and rotation is
the rotation of the polygon in radians.
offsets are a sequence of x,y tuples that give the centers of
the polygon in data coordinates, and transOffset is the
Transformation instance used to transform the centers onto the
canvas.
dpi is the figure dpi instance, and is required to do the area
scaling.
"""
PatchCollection.__init__(self,**kwargs)
self._sizes = asarray(sizes)
self._dpi = dpi
r = 1.0/math.sqrt(math.pi) # unit area
theta = (2*math.pi/numsides)*arange(numsides) + rotation
self._verts = zip( r*sin(theta), r*cos(theta) )
def hist(y, bins=10, normed=0):
"""
Return the histogram of y with bins equally sized bins. If bins
is an array, use the bins. Return value is
(n,x) where n is the count for each bin in x
If normed is False, return the counts in the first element of the
return tuple. If normed is True, return the probability density
n/(len(y)*dbin)
If y has rank>1, it will be raveled
Credits: the Numeric 22 documentation
"""
y = asarray(y)
if len(y.shape)>1: y = ravel(y)
if not iterable(bins):
ymin, ymax = min(y), max(y)
if ymin==ymax:
ymin -= 0.5
ymax += 0.5
bins = linspace(ymin, ymax, bins)
n = searchsorted(sort(y), bins)
n = diff(concatenate([n, [len(y)]]))
if normed:
db = bins[1]-bins[0]
return 1/(len(y)*db)*n, bins
else:
return n, bins
def __call__(self, value):
vmin = self.vmin
vmax = self.vmax
if type(value) in [IntType, FloatType]:
vtype = "scalar"
val = array([value])
else:
vtype = "array"
val = asarray(value)
if vmin is None or vmax is None:
rval = ravel(val)
if vmin is None:
vmin = amin(rval)
if vmax is None:
vmax = amax(rval)
if vmin > vmax:
raise ValueError("minvalue must be less than or equal to maxvalue")
elif vmin == vmax:
return 0.0 * value
else:
val = where(val < vmin, vmin, val)
val = where(val > vmax, vmax, val)
result = (1.0 / (vmax - vmin)) * (val - vmin)
if vtype == "scalar":
result = result[0]
return result
def longest_ones(x):
"""
return the indicies of the longest stretch of contiguous ones in x,
assuming x is a vector of zeros and ones.
If there are two equally long stretches, pick the first
"""
x = asarray(x)
if len(x)==0: return array([])
#print 'x', x
ind = find(x==0)
if len(ind)==0: return arange(len(x))
if len(ind)==len(x): return array([])
y = zeros( (len(x)+2,), Int)
y[1:-1] = x
d = diff(y)
#print 'd', d
up = find(d == 1);
dn = find(d == -1);
#print 'dn', dn, 'up', up,
ind = find( dn-up == max(dn - up))
# pick the first
if iterable(ind): ind = ind[0]
ind = arange(up[ind], dn[ind])
return ind
def rem(x,y):
"""
Remainder after division.
rem(x,y) is equivalent to x - y.*fix(x./y) in case y is not zero.
By convention, rem(x,0) returns None.
We keep the convention by Matlab:
"The input x and y must be real arrays of the same size, or real scalars."
"""
x,y = asarray(x),asarray(y)
if numerix.shape(x) == numerix.shape(y) or numerix.shape(y) == ():
try:
return x - y * fix(x/y)
except OverflowError:
return None
raise RuntimeError('Dimension error')
def __call__(self, X, alpha=1.0):
"""
X is either a scalar or an array (of any dimension).
If scalar, a tuple of rgba values is returned, otherwise
an array with the new shape = oldshape+(4,). Any values
that are outside the 0,1 interval are clipped to that
interval before generating rgb values.
Alpha must be a scalar
"""
if not self._isinit:
self._init()
alpha = min(alpha, 1.0) # alpha must be between 0 and 1
alpha = max(alpha, 0.0)
if type(X) in [IntType, FloatType]:
vtype = "scalar"
xa = array([X])
else:
vtype = "array"
xa = asarray(X)
# assume the data is properly normalized
# xa = where(xa>1.,1.,xa)
# xa = where(xa<0.,0.,xa)
xa = (xa * (self.N - 1)).astype(Int)
rgba = zeros(xa.shape + (4,), Float)
rgba[..., 0] = take(self._red_lut, xa)
rgba[..., 1] = take(self._green_lut, xa)
rgba[..., 2] = take(self._blue_lut, xa)
rgba[..., 3] = alpha
if vtype == "scalar":
rgba = tuple(rgba[0, :])
return rgba
def intwave(wavelet, precision=8):
"""
intwave(wavelet, precision=8) -> [int_psi, x]
- for orthogonal wavelets
intwave(wavelet, precision=8) -> [int_psi_d, int_psi_r, x]
- for other wavelets
intwave((function_approx, x), precision=8) -> [int_function, x]
- for (function approx., x grid) pair
Integrate *psi* wavelet function from -Inf to x using the rectangle
integration method.
wavelet - Wavelet to integrate (Wavelet object, wavelet name string
or (wavelet function approx., x grid) pair)
precision = 8 - Precision that will be used for wavelet function
approximation computed with the wavefun(level=precision)
Wavelet's method.
(function_approx, x) - Function to integrate on the x grid. Used instead
of Wavelet object to allow custom wavelet functions.
"""
if isinstance(wavelet, tuple):
psi, x = asarray(wavelet[0]), asarray(wavelet[1])
step = x[1] - x[0]
return integrate(psi, step), x
else:
if not isinstance(wavelet, WAVELET_CLASSES):
wavelet = wavelet_for_name(wavelet)
functions_approximations = wavelet.wavefun(precision)
if len(functions_approximations) == 2: # continuous wavelet
psi, x = functions_approximations
step = x[1] - x[0]
return integrate(psi, step), x
elif len(functions_approximations) == 3: # orthogonal wavelet
phi, psi, x = functions_approximations
step = x[1] - x[0]
return integrate(psi, step), x
else: # biorthogonal wavelet
phi_d, psi_d, phi_r, psi_r, x = functions_approximations
step = x[1] - x[0]
return integrate(psi_d, step), integrate(psi_r, step), x
def set_data(self, *args):
"""
Set the x and y data
ACCEPTS: (array xdata, array ydata)
"""
if len(args) == 1:
x, y = args[0]
else:
x, y = args
try:
del self._xc, self._yc
except AttributeError:
pass
self._x_orig = x
self._y_orig = y
x = ma.ravel(x)
y = ma.ravel(y)
if len(x) == 1 and len(y) > 1:
x = x * ones(y.shape, Float)
if len(y) == 1 and len(x) > 1:
y = y * ones(x.shape, Float)
if len(x) != len(y):
raise RuntimeError("xdata and ydata must be the same length")
mx = ma.getmask(x)
my = ma.getmask(y)
mask = ma.mask_or(mx, my)
if mask is not None:
x = ma.masked_array(x, mask=mask).compressed()
y = ma.masked_array(y, mask=mask).compressed()
self._segments = unmasked_index_ranges(mask)
else:
self._segments = None
self._x = asarray(x, Float)
self._y = asarray(y, Float)
if self._useDataClipping:
self._xsorted = self._is_sorted(self._x)
self._logcache = None
def scanner(s):
"""
Split a string into mathtext and non-mathtext parts. mathtext is
surrounded by $ symbols. quoted \$ are ignored
All slash quotes dollar signs are ignored
The number of unquoted dollar signs must be even
Return value is a list of (substring, inmath) tuples
"""
if not len(s): return [(s, False)]
#print 'testing', s, type(s)
inddollar = nonzero(asarray(equal(s,'$')))
quoted = dict([ (ind,1) for ind in nonzero(asarray(equal(s,'\\')))])
indkeep = [ind for ind in inddollar if not quoted.has_key(ind-1)]
if len(indkeep)==0:
return [(s, False)]
if len(indkeep)%2:
raise ValueError('Illegal string "%s" (must have balanced dollar signs)'%s)
Ns = len(s)
indkeep = [ind for ind in indkeep]
# make sure we start with the first element
if indkeep[0]!=0: indkeep.insert(0,0)
# and end with one past the end of the string
indkeep.append(Ns+1)
Nkeep = len(indkeep)
results = []
inmath = s[0] == '$'
for i in range(Nkeep-1):
i0, i1 = indkeep[i], indkeep[i+1]
if not inmath:
if i0>0: i0 +=1
else:
i1 += 1
if i0>=Ns: break
results.append((s[i0:i1], inmath))
inmath = not inmath
return results
def locate_label(self, linecontour, labelwidth):
"""find a good place to plot a label (relatively flat
part of the contour) and the angle of rotation for the
text object
"""
nsize= len(linecontour)
if labelwidth > 1:
xsize = int(ceil(nsize/labelwidth))
else:
xsize = 1
if xsize == 1:
ysize = nsize
else:
ysize = labelwidth
XX = resize(asarray(linecontour)[:,0],(xsize, ysize))
YY = resize(asarray(linecontour)[:,1],(xsize,ysize))
yfirst = YY[:,0]
ylast = YY[:,-1]
xfirst = XX[:,0]
xlast = XX[:,-1]
s = ( (reshape(yfirst, (xsize,1))-YY) *
(reshape(xlast,(xsize,1)) - reshape(xfirst,(xsize,1)))
- (reshape(xfirst,(xsize,1))-XX)
* (reshape(ylast,(xsize,1)) - reshape(yfirst,(xsize,1))) )
L=sqrt((xlast-xfirst)**2+(ylast-yfirst)**2)
dist = add.reduce(([(abs(s)[i]/L[i]) for i in range(xsize)]),-1)
x,y,ind = self.get_label_coords(dist, XX, YY, ysize, labelwidth)
#print 'ind, x, y', ind, x, y
angle = arctan2(ylast - yfirst, xlast - xfirst)
rotation = angle[ind]*180/pi
if rotation > 90:
rotation = rotation -180
if rotation < -90:
rotation = 180 + rotation
# There must be a more efficient way...
lc = [tuple(l) for l in linecontour]
dind = lc.index((x,y))
#print 'dind', dind
#dind = list(linecontour).index((x,y))
return x,y, rotation, dind
def polyfit(x,y,N):
"""
Do a best fit polynomial of order N of y to x. Return value is a
vector of polynomial coefficients [pk ... p1 p0]. Eg, for N=2
p2*x0^2 + p1*x0 + p0 = y1
p2*x1^2 + p1*x1 + p0 = y1
p2*x2^2 + p1*x2 + p0 = y2
.....
p2*xk^2 + p1*xk + p0 = yk
Method: if X is a the Vandermonde Matrix computed from x (see
http://mathworld.wolfram.com/VandermondeMatrix.html), then the
polynomial least squares solution is given by the 'p' in
X*p = y
where X is a len(x) x N+1 matrix, p is a N+1 length vector, and y
is a len(x) x 1 vector
This equation can be solved as
p = (XT*X)^-1 * XT * y
where XT is the transpose of X and -1 denotes the inverse.
For more info, see
http://mathworld.wolfram.com/LeastSquaresFittingPolynomial.html,
but note that the k's and n's in the superscripts and subscripts
on that page. The linear algebra is correct, however.
See also polyval
"""
x = asarray(x)+0.
y = asarray(y)+0.
y = reshape(y, (len(y),1))
X = Matrix(vander(x, N+1))
Xt = Matrix(transpose(X))
c = array(linear_algebra.inverse(Xt*X)*Xt*y) # convert back to array
c.shape = (N+1,)
return c
def _contour_args(self, *args):
if self.filled: fn = 'contourf'
else: fn = 'contour'
Nargs = len(args)
if Nargs <= 2:
z = args[0]
x, y = self._initialize_x_y(z)
elif Nargs <=4:
x,y,z = self._check_xyz(args[:3])
else:
raise TypeError("Too many arguments to %s; see help(%s)" % (fn,fn))
z = ma.asarray(z) # Convert to native masked array format if necessary.
self.zmax = ma.maximum(z)
self.zmin = ma.minimum(z)
self._auto = False
if self.levels is None:
if Nargs == 1 or Nargs == 3:
lev = self._autolev(z, 7)
else: # 2 or 4 args
level_arg = args[-1]
if type(level_arg) == int:
lev = self._autolev(z, level_arg)
elif iterable(level_arg) and len(shape(level_arg)) == 1:
lev = array([float(fl) for fl in level_arg])
else:
raise TypeError("Last %s arg must give levels; see help(%s)" % (fn,fn))
if self.filled and len(lev) < 2:
raise ValueError("Filled contours require at least 2 levels.")
# Workaround for cntr.c bug wrt masked interior regions:
#if filled:
# z = ma.masked_array(z.filled(-1e38))
# It's not clear this is any better than the original bug.
self.levels = lev
#if self._auto and self.extend in ('both', 'min', 'max'):
# raise TypeError("Auto level selection is inconsistent "
# + "with use of 'extend' kwarg")
self._levels = list(self.levels)
if self.extend in ('both', 'min'):
self._levels.insert(0, self.zmin - 1)
if self.extend in ('both', 'max'):
self._levels.append(self.zmax + 1)
self._levels = asarray(self._levels)
self.vmin = amin(self.levels) # alternative would be self.layers
self.vmax = amax(self.levels)
if self.extend in ('both', 'min') or self.clip_ends:
self.vmin = 2 * self.levels[0] - self.levels[1]
if self.extend in ('both', 'max') or self.clip_ends:
self.vmax = 2 * self.levels[-1] - self.levels[-2]
self.layers = self._levels # contour: a line is a thin layer
if self.filled:
self.layers = 0.5 * (self._levels[:-1] + self._levels[1:])
if self.extend in ('both', 'min') or self.clip_ends:
self.layers[0] = 0.5 * (self.vmin + self._levels[1])
if self.extend in ('both', 'max') or self.clip_ends:
self.layers[-1] = 0.5 * (self.vmax + self._levels[-2])
return (x, y, z)
def set_data(self, x, y):
try: del self._xc, self._yc
except AttributeError: pass
self._x = asarray(x, Float)
self._y = asarray(y, Float)
if len(self._x.shape)>1: self._x = ravel(self._x)
if len(self._y.shape)>1: self._y = ravel(self._y)
if len(self._y)==1 and len(self._x)>1:
self._y = self._y*ones(self._x.shape, Float)
if len(self._x) != len(self._y):
raise RuntimeError('xdata and ydata must be the same length')
if self._useDataClipping: self._xsorted = self._is_sorted(self._x)
def date2num(d):
"""
d is either a datetime instance or a sequence of datetimes
return value is a floating point number (or sequence of floats)
which gives number of days (fraction part represents hours,
minutes, seconds) since 0001-01-01 00:00:00 UTC
"""
if not iterable(d): return _to_ordinalf(d)
else: return asarray([_to_ordinalf(val) for val in d])
def centfrq(wavelet, precision=8):
"""
centfrq(wavelet, precision=8) -> float
- for orthogonal wavelets
centfrq((function_approx, x), precision=8) -> float
- for (function approx., x grid) pair
Computes the central frequency of the *psi* wavelet function.
wavelet - Wavelet (Wavelet object, wavelet name string
or (wavelet function approx., x grid) pair)
precision = 8 - Precision that will be used for wavelet function
approximation computed with the wavefun(level=precision)
Wavelet's method.
(function_approx, xgrid) - Function defined on xgrid. Used instead
of Wavelet object to allow custom wavelet functions.
"""
if isinstance(wavelet, tuple):
psi, x = asarray(wavelet[0]), asarray(wavelet[1])
else:
if not isinstance(wavelet, WAVELET_CLASSES):
wavelet = wavelet_for_name(wavelet)
functions_approximations = wavelet.wavefun(precision)
if len(functions_approximations) == 2:
psi, x = functions_approximations
else:
# (psi, x) for (phi, psi, x)
# (psi_d, x) for (phi_d, psi_d, phi_r, psi_r, x)
psi, x = functions_approximations[1], functions_approximations[-1]
domain = float(x[-1] - x[0])
assert domain > 0
index = argmax(abs(fft(psi)[1:])) + 2
if index > len(psi) / 2:
index = len(psi) - index + 2
return 1.0 / (domain / (index - 1))
def orthfilt(scaling_filter):
assert len(scaling_filter) % 2 == 0
scaling_filter = asarray(scaling_filter, dtype=float64)
rec_lo = sqrt(2) * scaling_filter / sum(scaling_filter)
dec_lo = rec_lo[::-1]
rec_hi = qmf(rec_lo)
dec_hi = rec_hi[::-1]
return (dec_lo, dec_hi, rec_lo, rec_hi)
def specgram(x, NFFT=256, Fs=2, detrend=detrend_none,
window=window_hanning, noverlap=128):
"""
Compute a spectrogram of data in x. Data are split into NFFT
length segements and the PSD of each section is computed. The
windowing function window is applied to each segment, and the
amount of overlap of each segment is specified with noverlap
See pdf for more info.
The returned times are the midpoints of the intervals over which
the ffts are calculated
"""
x = asarray(x)
assert(NFFT>noverlap)
if log(NFFT)/log(2) != int(log(NFFT)/log(2)):
raise ValueError, 'NFFT must be a power of 2'
# zero pad x up to NFFT if it is shorter than NFFT
if len(x)<NFFT:
n = len(x)
x = resize(x, (NFFT,))
x[n:] = 0
# for real x, ignore the negative frequencies
if typecode(x)==Complex: numFreqs=NFFT
else: numFreqs = NFFT//2+1
windowVals = window(ones((NFFT,),typecode(x)))
step = NFFT-noverlap
ind = arange(0,len(x)-NFFT+1,step)
n = len(ind)
Pxx = zeros((numFreqs,n), Float)
# do the ffts of the slices
for i in range(n):
thisX = x[ind[i]:ind[i]+NFFT]
thisX = windowVals*detrend(thisX)
fx = absolute(fft(thisX))**2
# Scale the spectrum by the norm of the window to compensate for
# windowing loss; see Bendat & Piersol Sec 11.5.2
Pxx[:,i] = divide(fx[:numFreqs], norm(windowVals)**2)
t = 1/Fs*(ind+NFFT/2)
freqs = Fs/NFFT*arange(numFreqs)
return Pxx, freqs, t
def set_data(self, A, shape=None):
"""
Set the image array
ACCEPTS: numeric/numarray/PIL Image A"""
# check if data is PIL Image without importing Image
if hasattr(A,'getpixel'): X = pil_to_array(A)
else: X = asarray(A) # assume array
if (X.typecode() != UInt8
or len(X.shape) != 3
or X.shape[2] > 4
or X.shape[2] < 3):
cm.ScalarMappable.set_array(self, X)
else:
self._A = X
self._imcache =None
def rank(x):
"""
Returns the rank of a matrix.
The rank is understood here as the an estimation of the number of
linearly independent rows or columns (depending on the size of the
matrix).
Note that numerix.mlab.rank() is not equivalent to Matlab's rank.
This function is!
"""
x = asarray(x)
u,s,v = numerix.mlab.svd(x)
# maxabs = numerix.mlab.max(numerix.absolute(s)) is also possible.
maxabs = norm(x)
maxdim = numerix.mlab.max(numerix.shape(x))
tol = maxabs*maxdim*_eps_approx
r = s>tol
return asum(r)
def rank(x):
"""
Returns the rank of a matrix.
The rank is understood here as the an estimation of the number of
linearly independent rows or columns (depending on the size of the
matrix).
Note that MLab.rank() is not equivalent to Matlab's rank.
This function is!
"""
x = numerix.asarray(x)
u, s, v = MLab.svd(x)
# maxabs = MLab.max(numerix.absolute(s)) is also possible.
maxabs = norm(x)
maxdim = MLab.max(numerix.shape(x))
tol = maxabs * maxdim * _eps_approx
r = s > tol
return MLab.sum(r)
def norm(x, y=2):
"""
Norm of a matrix or a vector according to Matlab.
The description is taken from Matlab:
For matrices...
NORM(X) is the largest singular value of X, max(svd(X)).
NORM(X,2) is the same as NORM(X).
NORM(X,1) is the 1-norm of X, the largest column sum,
= max(sum(abs((X)))).
NORM(X,inf) is the infinity norm of X, the largest row sum,
= max(sum(abs((X')))).
NORM(X,'fro') is the Frobenius norm, sqrt(sum(diag(X'*X))).
NORM(X,P) is available for matrix X only if P is 1, 2, inf or 'fro'.
For vectors...
NORM(V,P) = sum(abs(V).^P)^(1/P).
NORM(V) = norm(V,2).
NORM(V,inf) = max(abs(V)).
NORM(V,-inf) = min(abs(V)).
"""
x = asarray(x)
if numerix.mlab.rank(x) == 2:
if y == 2:
return numerix.mlab.max(numerix.mlab.svd(x)[1])
elif y == 1:
return numerix.mlab.max(asum(absolute((x))))
elif y == 'inf':
return numerix.mlab.max(asum(absolute((transpose(x)))))
elif y == 'fro':
return numerix.mlab.sqrt(
asum(numerix.mlab.diag(matrixmultiply(transpose(x), x))))
else:
verbose.report_error('Second argument not permitted for matrices')
return None
else:
if y == 'inf':
return numerix.mlab.max(absolute(x))
elif y == '-inf':
return numerix.mlab.min(absolute(x))
else:
return power(asum(power(absolute(x), y)), 1 / float(y))
def polyval(p, x):
"""
y = polyval(p,x)
p is a vector of polynomial coeffients and y is the polynomial
evaluated at x.
Example code to remove a polynomial (quadratic) trend from y:
p = polyfit(x, y, 2)
trend = polyval(p, x)
resid = y - trend
See also polyfit
"""
x = asarray(x) + 0.
p = reshape(p, (len(p), 1))
X = vander(x, len(p))
y = matrixmultiply(X, p)
return reshape(y, x.shape)
def __init__(self, dpi, numsides, rotation=0, sizes=(1, ), **kwargs):
"""
Draw a regular polygon with numsides. sizes gives the area of the
circle circumscribing the regular polygon and rotation is the rotation
of the polygon in radians.
offsets are a sequence of x,y tuples that give the centers of the
polygon in data coordinates, and transOffset is the Transformation
instance used to transform the centers onto the canvas.
dpi is the figure dpi instance, and is required to do the area
scaling.
"""
PatchCollection.__init__(self, **kwargs)
self._sizes = asarray(sizes)
self._dpi = dpi
r = 1.0 / math.sqrt(math.pi) # unit area
theta = (2 * math.pi / numsides) * arange(numsides) + rotation
self._verts = zip(r * sin(theta), r * cos(theta))
def hist(y, bins=10, normed=0):
"""
Return the histogram of y with bins equally sized bins. If bins
is an array, use the bins. Return value is
(n,x) where n is the count for each bin in x
If normed is False, return the counts in the first element of the
return tuple. If normed is True, return the probability density
n/(len(y)*dbin)
If y has rank>1, it will be raveled
Credits: the Numeric 22 documentation
"""
y = asarray(y)
if len(y.shape)>1: y = ravel(y)
if not iterable(bins):
ymin, ymax = min(y), max(y)
if ymin==ymax:
ymin -= 0.5
ymax += 0.5
if bins==1: bins=ymax
dy = (ymax-ymin)/bins
bins = ymin + dy*arange(bins)
n = searchsorted(sort(y), bins)
n = diff(concatenate([n, [len(y)]]))
if normed:
db = bins[1]-bins[0]
return 1/(len(y)*db)*n, bins
else:
return n, bins
def draw(self, renderer):
if not self.get_visible(): return
renderer.open_group('regpolycollection')
self._transform.freeze()
self._transOffset.freeze()
self.update_scalarmappable()
self._update_verts()
scales = sqrt(asarray(self._sizes) * self._dpi.get() / 72.0)
if is_string_like(self._edgecolors) and self._edgecolors[:2] == 'No':
#self._edgecolors = self._facecolors
self._linewidths = (0, )
# print 'in draw(), self._offsets = %s' % (`self._offsets`)
renderer.draw_regpoly_collection(self.clipbox, self._offsets,
self._transOffset, self._verts,
scales, self._facecolors,
self._edgecolors, self._linewidths,
self._antialiaseds)
self._transform.thaw()
self._transOffset.thaw()
renderer.close_group('regpolycollection')
def __init__(
self,
segments, # Can be None.
linewidths=None,
colors=None,
antialiaseds=None,
linestyle='solid',
offsets=None,
transOffset=None, #identity_transform(),
norm=None,
cmap=None,
):
"""
segments is a sequence of ( line0, line1, line2), where
linen = (x0, y0), (x1, y1), ... (xm, ym), or the
equivalent numerix array with two columns.
Each line can be a different length.
colors must be a tuple of RGBA tuples (eg arbitrary color
strings, etc, not allowed).
antialiaseds must be a sequence of ones or zeros
linestyles is a string or dash tuple. Legal string values are
solid|dashed|dashdot|dotted. The dash tuple is (offset, onoffseq)
where onoffseq is an even length tuple of on and off ink in points.
If linewidths, colors, or antialiaseds is None, they default to
their rc params setting, in sequence form.
If offsets and transOffset are not None, then
offsets are transformed by transOffset and applied after
the segments have been transformed to display coordinates.
If offsets is not None but transOffset is None, then the
offsets are added to the segments before any transformation.
In this case, a single offset can be specified as offsets=(xo,yo),
and this value will be
added cumulatively to each successive segment, so as
to produce a set of successively offset curves.
norm = None, # optional for ScalarMappable
cmap = None, # ditto
The use of ScalarMappable is optional. If the ScalarMappable
matrix _A is not None (ie a call to set_array has been made), at
draw time a call to scalar mappable will be made to set the colors.
"""
Collection.__init__(self)
ScalarMappable.__init__(self, norm, cmap)
if linewidths is None:
linewidths = (rcParams['lines.linewidth'], )
if colors is None:
colors = (rcParams['lines.color'], )
if antialiaseds is None:
antialiaseds = (rcParams['lines.antialiased'], )
self._colors = colorConverter.to_rgba_list(colors)
self._aa = antialiaseds
self._lw = linewidths
self.set_linestyle(linestyle)
self._uniform_offsets = None
if offsets is not None:
offsets = asarray(offsets)
if len(offsets.shape) == 1:
offsets = offsets[newaxis, :] # Make it Nx2.
if transOffset is None:
if offsets is not None:
self._uniform_offsets = offsets
offsets = None
transOffset = identity_transform()
self._offsets = offsets
self._transOffset = transOffset
self.set_segments(segments)
def julian2num(j):
'convert a Julian date (or sequence) to a matplotlib date (or sequence)'
if iterable(j): j = asarray(j)
return j + 1721425.5
def num2epoch(d):
"""
convert days since 0001 to epoch. d can be a number or sequence
"""
spd = 24.*3600.
return (asarray(d)-719163)*spd
def num2julian(n):
'convert a matplotlib date (or seguence) to a Julian date (or sequence)'
if iterable(n): n = asarray(n)
return n - 1721425.5
def break_linecontour(self, linecontour, rot, labelwidth, ind):
"break a contour in two contours at the location of the label"
lcsize = len(linecontour)
hlw = int(labelwidth / 2)
#length of label in screen coords
ylabel = abs(hlw * sin(rot * pi / 180))
xlabel = abs(hlw * cos(rot * pi / 180))
trans = self.ax.transData
slc = trans.seq_xy_tups(linecontour)
x, y = slc[ind]
xx = asarray(slc)[:, 0].copy()
yy = asarray(slc)[:, 1].copy()
#indices which are under the label
inds = nonzero(((xx < x + xlabel) & (xx > x - xlabel))
& ((yy < y + ylabel) & (yy > y - ylabel)))
if len(inds) > 0:
#if the label happens to be over the beginning of the
#contour, the entire contour is removed, i.e.
#indices to be removed are
#inds= [0,1,2,3,305,306,307]
#should rewrite this in a better way
linds = nonzero(inds[1:] - inds[:-1] != 1)
if inds[0] == 0 and len(linds) != 0:
ii = inds[linds[0]]
lc1 = linecontour[ii + 1:inds[ii + 1]]
lc2 = []
else:
lc1 = linecontour[:inds[0]]
lc2 = linecontour[inds[-1] + 1:]
else:
lc1 = linecontour[:ind]
lc2 = linecontour[ind + 1:]
if rot < 0:
new_x1, new_y1 = x - xlabel, y + ylabel
new_x2, new_y2 = x + xlabel, y - ylabel
else:
new_x1, new_y1 = x - xlabel, y - ylabel
new_x2, new_y2 = x + xlabel, y + ylabel
new_x1d, new_y1d = trans.inverse_xy_tup((new_x1, new_y1))
new_x2d, new_y2d = trans.inverse_xy_tup((new_x2, new_y2))
new_xy1 = array(((new_x1d, new_y1d), ))
new_xy2 = array(((new_x2d, new_y2d), ))
if rot > 0:
if (len(lc1) > 0 and (lc1[-1][0] <= new_x1d)
and (lc1[-1][1] <= new_y1d)):
lc1 = concatenate((lc1, new_xy1))
#lc1.append((new_x1d, new_y1d))
if (len(lc2) > 0 and (lc2[0][0] >= new_x2d)
and (lc2[0][1] >= new_y2d)):
lc2 = concatenate((new_xy2, lc2))
#lc2.insert(0, (new_x2d, new_y2d))
else:
if (len(lc1) > 0
and ((lc1[-1][0] <= new_x1d) and (lc1[-1][1] >= new_y1d))):
lc1 = concatenate((lc1, new_xy1))
#lc1.append((new_x1d, new_y1d))
if (len(lc2) > 0
and ((lc2[0][0] >= new_x2d) and (lc2[0][1] <= new_y2d))):
lc2 = concatenate((new_xy2, lc2))
#lc2.insert(0, (new_x2d, new_y2d))
return [lc1, lc2]
def _contour_args(self, *args):
if self.filled: fn = 'contourf'
else: fn = 'contour'
Nargs = len(args)
if Nargs <= 2:
z = args[0]
x, y = self._initialize_x_y(z)
elif Nargs <= 4:
x, y, z = self._check_xyz(args[:3])
else:
raise TypeError("Too many arguments to %s; see help(%s)" %
(fn, fn))
z = ma.asarray(
z) # Convert to native masked array format if necessary.
self.zmax = ma.maximum(z)
self.zmin = ma.minimum(z)
self._auto = False
if self.levels is None:
if Nargs == 1 or Nargs == 3:
lev = self._autolev(z, 7)
else: # 2 or 4 args
level_arg = args[-1]
if type(level_arg) == int:
lev = self._autolev(z, level_arg)
elif iterable(level_arg) and len(shape(level_arg)) == 1:
lev = array([float(fl) for fl in level_arg])
else:
raise TypeError(
"Last %s arg must give levels; see help(%s)" %
(fn, fn))
if self.filled and len(lev) < 2:
raise ValueError("Filled contours require at least 2 levels.")
# Workaround for cntr.c bug wrt masked interior regions:
#if filled:
# z = ma.masked_array(z.filled(-1e38))
# It's not clear this is any better than the original bug.
self.levels = lev
#if self._auto and self.extend in ('both', 'min', 'max'):
# raise TypeError("Auto level selection is inconsistent "
# + "with use of 'extend' kwarg")
self._levels = list(self.levels)
if self.extend in ('both', 'min'):
self._levels.insert(0, self.zmin - 1)
if self.extend in ('both', 'max'):
self._levels.append(self.zmax + 1)
self._levels = asarray(self._levels)
self.vmin = amin(self.levels) # alternative would be self.layers
self.vmax = amax(self.levels)
if self.extend in ('both', 'min') or self.clip_ends:
self.vmin = 2 * self.levels[0] - self.levels[1]
if self.extend in ('both', 'max') or self.clip_ends:
self.vmax = 2 * self.levels[-1] - self.levels[-2]
self.layers = self._levels # contour: a line is a thin layer
if self.filled:
self.layers = 0.5 * (self._levels[:-1] + self._levels[1:])
if self.extend in ('both', 'min') or self.clip_ends:
self.layers[0] = 0.5 * (self.vmin + self._levels[1])
if self.extend in ('both', 'max') or self.clip_ends:
self.layers[-1] = 0.5 * (self.vmax + self._levels[-2])
return (x, y, z)
def set_segments(self, segments):
if segments is None: return
self._segments = [asarray(seg) for seg in segments]
if self._uniform_offsets is not None:
self._add_offsets()
