def pdbBox(line):
''' Parses a gro box line and returns a pdb CRYST1 line '''
from math import degrees
from chempy.cpv import length, get_angle
v = [10*float(i) for i in line.split()] + 6*[0] # Padding for rectangular boxes
v1, v2, v3 = (v[0], v[3], v[4]), (v[5], v[1], v[6]), (v[7], v[8], v[2])
a = length(v1)
b = length(v2)
c = length(v3)
alpha = degrees(get_angle(v2, v3))
beta = degrees(get_angle(v1, v3))
gamma = degrees(get_angle(v1, v2))
return _pdbBoxLine % (a, b, c, alpha, beta, gamma)
def pdbBox(line):
''' Parses a gro box line and returns a pdb CRYST1 line '''
from math import degrees
from chempy.cpv import length, get_angle
v = [10*float(i) for i in line.split()] + 6*[0] # Padding for rectangular boxes
v1, v2, v3 = (v[0], v[3], v[4]), (v[5], v[1], v[6]), (v[7], v[8], v[2])
a = length(v1)
b = length(v2)
c = length(v3)
alpha = degrees(get_angle(v2, v3))
beta = degrees(get_angle(v1, v3))
gamma = degrees(get_angle(v1, v2))
return _pdbBoxLine % (a, b, c, alpha, beta, gamma)
def angle_between_helices(selection1,
selection2,
method='helix_orientation',
visualize=1,
quiet=0):
'''
DESCRIPTION
Calculates the angle between two helices
USAGE
angle_between_helices selection1, selection2 [, method [, visualize]]
ARGUMENTS
selection1 = string: atom selection of first helix
selection2 = string: atom selection of second helix
method = string: function to calculate orientation {default: helix_orientation}
or int: 0: helix_orientation, 1: helix_orientation_hbond,
2: loop_orientation, 3: cafit_orientation
visualize = 0 or 1: show fitted vector as arrow {default: 1}
SEE ALSO
helix_orientation, helix_orientation_hbond, loop_orientation, cafit_orientation
'''
visualize, quiet = int(visualize), int(quiet)
methods = {
'0': helix_orientation,
'1': helix_orientation_hbond,
'2': loop_orientation,
'3': cafit_orientation,
}
methods.update([(x.__name__, x) for x in methods.values()])
try:
orientation = methods[str(method)]
except KeyError:
print 'no such method:', method
raise CmdException
if not quiet:
print 'Using method:', orientation.__name__
cen1, dir1 = orientation(selection1, visualize, quiet=1)
cen2, dir2 = orientation(selection2, visualize, quiet=1)
angle = cpv.get_angle(dir1, dir2)
angle_deg = math.degrees(angle)
if not quiet:
print 'Angle: %.2f deg' % (angle_deg)
if visualize:
cmd.zoom('(%s) or (%s)' % (selection1, selection2), buffer=2)
return angle_deg
def helix_orientation(selection, visualize=1, sigma_cutoff=1.5, quiet=0):
'''
DESCRIPTION
Get the center and direction of a helix as vectors. Will only work
for helices and gives slightly different results than loop_orientation.
Averages direction of C(i)->O(i) bonds.
USAGE
helix_orientation selection [, visualize [, sigma_cutoff]]
ARGUMENTS
selection = string: atom selection of helix
visualize = 0 or 1: show fitted vector as arrow {default: 1}
sigma_cutoff = float: drop outliers outside
(standard_deviation * sigma_cutoff) {default: 1.5}
SEE ALSO
angle_between_helices, helix_orientation_hbond, loop_orientation, cafit_orientation
'''
visualize, quiet, sigma_cutoff = int(visualize), int(quiet), float(
sigma_cutoff)
stored.x = dict()
cmd.iterate_state(
STATE, '(%s) and name C+O' % (selection),
'stored.x.setdefault(chain + resi, dict())[name] = x,y,z')
vec_list = []
count = 0
for x in stored.x.itervalues():
if 'C' in x and 'O' in x:
vec_list.append(cpv.sub(x['O'], x['C']))
count += 1
if count == 0:
print 'warning: count == 0'
raise CmdException
vec = _vec_sum(vec_list)
if count > 2 and sigma_cutoff > 0:
angle_list = [cpv.get_angle(vec, x) for x in vec_list]
angle_mu, angle_sigma = _mean_and_std(angle_list)
vec_list = [
vec_list[i] for i in range(len(vec_list))
if abs(angle_list[i] - angle_mu) < angle_sigma * sigma_cutoff
]
if not quiet:
print 'Dropping %d outlier(s)' % (len(angle_list) - len(vec_list))
vec = _vec_sum(vec_list)
vec = cpv.normalize(vec)
return _common_orientation(selection, vec, visualize, quiet)
def helix_orientation(selection, visualize=1, sigma_cutoff=1.5, quiet=0):
"""
DESCRIPTION
Get the center and direction of a helix as vectors. Will only work
for helices and gives slightly different results than loop_orientation.
Averages direction of C(i)->O(i) bonds.
USAGE
helix_orientation selection [, visualize [, sigma_cutoff]]
ARGUMENTS
selection = string: atom selection of helix
visualize = 0 or 1: show fitted vector as arrow {default: 1}
sigma_cutoff = float: drop outliers outside
(standard_deviation * sigma_cutoff) {default: 1.5}
SEE ALSO
angle_between_helices, helix_orientation_hbond, loop_orientation, cafit_orientation
"""
visualize, quiet, sigma_cutoff = int(visualize), int(quiet), float(sigma_cutoff)
stored.x = dict()
cmd.iterate_state(
STATE, "(%s) and name C+O" % (selection), "stored.x.setdefault(chain + resi, dict())[name] = x,y,z"
)
vec_list = []
count = 0
for x in stored.x.values():
if "C" in x and "O" in x:
vec_list.append(cpv.sub(x["O"], x["C"]))
count += 1
if count == 0:
print("warning: count == 0")
raise CmdException
vec = _vec_sum(vec_list)
if count > 2 and sigma_cutoff > 0:
angle_list = [cpv.get_angle(vec, x) for x in vec_list]
angle_mu, angle_sigma = _mean_and_std(angle_list)
vec_list = [
vec_list[i] for i in range(len(vec_list)) if abs(angle_list[i] - angle_mu) < angle_sigma * sigma_cutoff
]
if not quiet:
print("Dropping %d outlier(s)" % (len(angle_list) - len(vec_list)))
vec = _vec_sum(vec_list)
vec = cpv.normalize(vec)
return _common_orientation(selection, vec, visualize, quiet)
def angle_between_helices(selection1, selection2, method='helix_orientation', visualize=1, quiet=0):
'''
DESCRIPTION
Calculates the angle between two helices
USAGE
angle_between_helices selection1, selection2 [, method [, visualize]]
ARGUMENTS
selection1 = string: atom selection of first helix
selection2 = string: atom selection of second helix
method = string: function to calculate orientation {default: helix_orientation}
or int: 0: helix_orientation, 1: helix_orientation_hbond,
2: loop_orientation, 3: cafit_orientation
visualize = 0 or 1: show fitted vector as arrow {default: 1}
SEE ALSO
helix_orientation, helix_orientation_hbond, loop_orientation, cafit_orientation
'''
visualize, quiet = int(visualize), int(quiet)
methods = {
'0': helix_orientation,
'1': helix_orientation_hbond,
'2': loop_orientation,
'3': cafit_orientation,
}
methods.update([(x.__name__, x) for x in methods.values()])
try:
orientation = methods[str(method)]
except KeyError:
print 'no such method:', method
raise CmdException
if not quiet:
print 'Using method:', orientation.__name__
cen1, dir1 = orientation(selection1, visualize, quiet=1)
cen2, dir2 = orientation(selection2, visualize, quiet=1)
angle = cpv.get_angle(dir1, dir2)
angle_deg = math.degrees(angle)
if not quiet:
print 'Angle: %.2f deg' % (angle_deg)
if visualize:
cmd.zoom('(%s) or (%s)' % (selection1, selection2), buffer=2)
return angle_deg
def angle_between_helices(selection1, selection2, method="helix_orientation", visualize=1, quiet=0):
"""
DESCRIPTION
Calculates the angle between two helices
USAGE
angle_between_helices selection1, selection2 [, method [, visualize]]
ARGUMENTS
selection1 = string: atom selection of first helix
selection2 = string: atom selection of second helix
method = string: function to calculate orientation {default: helix_orientation}
or int: 0: helix_orientation, 1: helix_orientation_hbond,
2: loop_orientation, 3: cafit_orientation
visualize = 0 or 1: show fitted vector as arrow {default: 1}
SEE ALSO
helix_orientation, helix_orientation_hbond, loop_orientation, cafit_orientation
"""
visualize, quiet = int(visualize), int(quiet)
methods = {"0": helix_orientation, "1": helix_orientation_hbond, "2": loop_orientation, "3": cafit_orientation}
methods.update([(x.__name__, x) for x in list(methods.values())])
try:
orientation = methods[str(method)]
except KeyError:
print("no such method: " + str(method))
raise CmdException
if not quiet:
print("Using method: " + orientation.__name__)
cen1, dir1 = orientation(selection1, visualize, quiet=1)
cen2, dir2 = orientation(selection2, visualize, quiet=1)
angle = cpv.get_angle(dir1, dir2)
angle_deg = math.degrees(angle)
if not quiet:
print("Angle: %.2f deg" % (angle_deg))
if visualize:
cmd.zoom("(%s) or (%s)" % (selection1, selection2), buffer=2)
return angle_deg
def angle_between_helices(selection1, selection2, method='helix',
state1=STATE, state2=STATE, visualize=1, quiet=1):
'''
DESCRIPTION
Calculates the angle between two helices
USAGE
angle_between_helices selection1, selection2 [, method [, visualize]]
ARGUMENTS
selection1 = string: atom selection of first helix
selection2 = string: atom selection of second helix
method = string: function to calculate orientation {default: helix_orientation}
visualize = 0 or 1: show fitted vector as arrow {default: 1}
EXAMPLE
fetch 2x19, async=0
select hel1, /2x19//B/23-36/
select hel2, /2x19//B/40-54/
angle_between_helices hel1, hel2
angle_between_helices hel1, hel2, cafit
SEE ALSO
helix_orientation, loop_orientation, cafit_orientation, angle_between_domains
'''
import math
state1, state2 = int(state1), int(state2)
visualize, quiet = int(visualize), int(quiet)
try:
orientation = globals()[methods_sc[str(method)]]
except KeyError:
print 'no such method:', method
raise CmdException
if not int(quiet):
print ' Using method:', orientation.__name__
cen1, dir1 = orientation(selection1, state1, visualize, quiet=1)
cen2, dir2 = orientation(selection2, state2, visualize, quiet=1)
angle = cpv.get_angle(dir1, dir2)
angle = math.degrees(angle)
if not quiet:
print ' Angle: %.2f deg' % (angle)
if visualize:
# measurement object for angle
center = cpv.scale(cpv.add(cen1, cen2), 0.5)
tmp = get_unused_name('_')
for pos in [center,
cpv.add(center, cpv.scale(dir1, 5.0)),
cpv.add(center, cpv.scale(dir2, 5.0))]:
cmd.pseudoatom(tmp, pos=list(pos), state=1)
name = get_unused_name('angle')
cmd.angle(name, *[(tmp, i) for i in [2,1,3]])
cmd.delete(tmp)
cmd.zoom('(%s) or (%s)' % (selection1, selection2), 2,
state1 if state1 == state2 else 0)
return angle
def torus(center=(0., 0., 0.), normal=(0., 0., 1.), radius=1., color='',
cradius=.25, samples=20, csamples=20):
'''
Generate and return a torus CGO with given center, normal
and ring radius.
'''
from math import cos, sin, pi
if color and isinstance(color, str):
color = list(cmd.get_color_tuple(color))
obj = []
axis = cpv.cross_product(normal, (0., 0., 1.))
angle = -cpv.get_angle(normal, (0., 0., 1.))
matrix = cpv.rotation_matrix(angle, cpv.normalize(axis))
obj_vertex = lambda x, y, z: obj.extend([VERTEX] + cpv.add(center,
cpv.transform(matrix, [x, y, z])))
obj_normal = lambda x, y, z: obj.extend([NORMAL] +
cpv.transform(matrix, [x, y, z]))
r = radius
cr = cradius
rr = 1.5 * cr
dv = 2 * pi / csamples
dw = 2 * pi / samples
v = 0.0
w = 0.0
while w < 2 * pi:
v = 0.0
c_w = cos(w)
s_w = sin(w)
c_wdw = cos(w + dw)
s_wdw = sin(w + dw)
obj.append(BEGIN)
obj.append(TRIANGLE_STRIP)
if color:
obj.append(COLOR)
obj.extend(color)
while v < 2 * pi + dv:
c_v = cos(v)
s_v = sin(v)
c_vdv = cos(v + dv)
s_vdv = sin(v + dv)
obj_normal(
(r + rr * c_v) * c_w - (r + cr * c_v) * c_w,
(r + rr * c_v) * s_w - (r + cr * c_v) * s_w,
(rr * s_v - cr * s_v))
obj_vertex(
(r + cr * c_v) * c_w,
(r + cr * c_v) * s_w,
cr * s_v)
obj_normal(
(r + rr * c_vdv) * c_wdw - (r + cr * c_vdv) * c_wdw,
(r + rr * c_vdv) * s_wdw - (r + cr * c_vdv) * s_wdw,
rr * s_vdv - cr * s_vdv)
obj_vertex(
(r + cr * c_vdv) * c_wdw,
(r + cr * c_vdv) * s_wdw,
cr * s_vdv)
v += dv
obj.append(END)
w += dw
return obj
def angle_between_helices(selection1,
selection2,
method='helix',
state1=STATE,
state2=STATE,
visualize=1,
quiet=1):
'''
DESCRIPTION
Calculates the angle between two helices
USAGE
angle_between_helices selection1, selection2 [, method [, visualize]]
ARGUMENTS
selection1 = string: atom selection of first helix
selection2 = string: atom selection of second helix
method = string: function to calculate orientation {default: helix_orientation}
visualize = 0 or 1: show fitted vector as arrow {default: 1}
EXAMPLE
fetch 2x19, bsync=0
select hel1, /2x19//B/23-36/
select hel2, /2x19//B/40-54/
angle_between_helices hel1, hel2
angle_between_helices hel1, hel2, cafit
SEE ALSO
helix_orientation, loop_orientation, cafit_orientation, angle_between_domains
'''
import math
state1, state2 = int(state1), int(state2)
visualize, quiet = int(visualize), int(quiet)
try:
orientation = globals()[methods_sc[str(method)]]
except KeyError:
print('no such method:', method)
raise CmdException
if not int(quiet):
print(' Using method:', orientation.__name__)
cen1, dir1 = orientation(selection1, state1, visualize, quiet=1)
cen2, dir2 = orientation(selection2, state2, visualize, quiet=1)
angle = cpv.get_angle(dir1, dir2)
angle = math.degrees(angle)
if not quiet:
print(' Angle: %.2f deg' % (angle))
if visualize:
# measurement object for angle
center = cpv.scale(cpv.add(cen1, cen2), 0.5)
tmp = get_unused_name('_')
for pos in [
center,
cpv.add(center, cpv.scale(dir1, 5.0)),
cpv.add(center, cpv.scale(dir2, 5.0))
]:
cmd.pseudoatom(tmp, pos=list(pos), state=1)
name = get_unused_name('angle')
cmd.angle(name, *[(tmp, i) for i in [2, 1, 3]])
cmd.delete(tmp)
cmd.zoom('(%s) or (%s)' % (selection1, selection2), 2,
state1 if state1 == state2 else 0)
return angle
def torus(center=(0., 0., 0.), normal=(0., 0., 1.), radius=1., color='',
cradius=.25, samples=20, csamples=20, _self=cmd):
'''
Generate and return a torus CGO with given center, normal
and ring radius.
'''
from math import cos, sin, pi
if color and isinstance(color, str):
color = list(_self.get_color_tuple(color))
obj = []
axis = cpv.cross_product(normal, (0., 0., 1.))
angle = -cpv.get_angle(normal, (0., 0., 1.))
matrix = cpv.rotation_matrix(angle, cpv.normalize(axis))
obj_vertex = lambda x, y, z: obj.extend([VERTEX] + cpv.add(center,
cpv.transform(matrix, [x, y, z])))
obj_normal = lambda x, y, z: obj.extend([NORMAL] +
cpv.transform(matrix, [x, y, z]))
r = radius
cr = cradius
rr = 1.5 * cr
dv = 2 * pi / csamples
dw = 2 * pi / samples
v = 0.0
w = 0.0
while w < 2 * pi:
v = 0.0
c_w = cos(w)
s_w = sin(w)
c_wdw = cos(w + dw)
s_wdw = sin(w + dw)
obj.append(BEGIN)
obj.append(TRIANGLE_STRIP)
if color:
obj.append(COLOR)
obj.extend(color)
while v < 2 * pi + dv:
c_v = cos(v)
s_v = sin(v)
c_vdv = cos(v + dv)
s_vdv = sin(v + dv)
obj_normal(
(r + rr * c_v) * c_w - (r + cr * c_v) * c_w,
(r + rr * c_v) * s_w - (r + cr * c_v) * s_w,
(rr * s_v - cr * s_v))
obj_vertex(
(r + cr * c_v) * c_w,
(r + cr * c_v) * s_w,
cr * s_v)
obj_normal(
(r + rr * c_vdv) * c_wdw - (r + cr * c_vdv) * c_wdw,
(r + rr * c_vdv) * s_wdw - (r + cr * c_vdv) * s_wdw,
rr * s_vdv - cr * s_vdv)
obj_vertex(
(r + cr * c_vdv) * c_wdw,
(r + cr * c_vdv) * s_wdw,
cr * s_vdv)
v += dv
obj.append(END)
w += dw
return obj
def rebuild(self) -> None:
"""
Rebuilds torus
"""
obj = []
axis = cpv.cross_product(self.normal.array(), (0., 0., 1.))
angle = -cpv.get_angle(self.normal.array(), (0., 0., 1.))
matrix = cpv.rotation_matrix(angle, cpv.normalize(axis))
def obj_vertex(x, y, z):
return [cgo.VERTEX] + cpv.add(self.center.array(),
cpv.transform(matrix, [x, y, z]))
def obj_normal(x, y, z):
return [cgo.NORMAL] + cpv.transform(matrix, [x, y, z])
r = self.radius
cr = self.cradius
rr = 1.5 * cr
dv = 2 * math.pi / self.csamples
dw = 2 * math.pi / self.samples
v = 0.0
w = 0.0
while w < 2 * math.pi:
v = 0.0
c_w = math.cos(w)
s_w = math.sin(w)
c_wdw = math.cos(w + dw)
s_wdw = math.sin(w + dw)
obj.append(cgo.BEGIN)
obj.append(cgo.TRIANGLE_STRIP)
obj.append(cgo.COLOR)
obj.extend(self.color.array())
while v < 2 * math.pi + dv:
c_v = math.cos(v)
s_v = math.sin(v)
c_vdv = math.cos(v + dv)
s_vdv = math.sin(v + dv)
obj.extend(
obj_normal((r + rr * c_v) * c_w - (r + cr * c_v) * c_w,
(r + rr * c_v) * s_w - (r + cr * c_v) * s_w,
(rr * s_v - cr * s_v)))
obj.extend(
obj_vertex((r + cr * c_v) * c_w, (r + cr * c_v) * s_w,
cr * s_v))
obj.extend(
obj_normal(
(r + rr * c_vdv) * c_wdw - (r + cr * c_vdv) * c_wdw,
(r + rr * c_vdv) * s_wdw - (r + cr * c_vdv) * s_wdw,
rr * s_vdv - cr * s_vdv))
obj.extend(
obj_vertex((r + cr * c_vdv) * c_wdw,
(r + cr * c_vdv) * s_wdw, cr * s_vdv))
v += dv
obj.append(cgo.END)
w += dw
self._data = obj
