def gyradius(selection='(all)', state=-1, quiet=1, *, _self=cmd):
'''
DESCRIPTION
Radius of gyration
Based on: http://pymolwiki.org/index.php/Radius_of_gyration
SEE ALSO
centerofmass
'''
from chempy import cpv
state, quiet = int(state), int(quiet)
if state < 0:
states = [_self.get_state()]
elif state == 0:
states = list(range(1, _self.count_states(selection) + 1))
else:
states = [state]
rg_sq_list = []
for state in states:
model = _self.get_model(selection, state)
x = [i.coord for i in model.atom]
mass = [i.get_mass() * i.q for i in model.atom if i.q > 0]
xm = [cpv.scale(v, m) for v, m in zip(x, mass)]
tmass = sum(mass)
rr = sum(cpv.dot_product(v, vm) for v, vm in zip(x, xm))
mm = sum((sum(i) / tmass)**2 for i in zip(*xm))
rg_sq_list.append(rr / tmass - mm)
rg = (sum(rg_sq_list) / len(rg_sq_list))**0.5
if not quiet:
print(' Radius of gyration: %.2f' % (rg))
return rg
def gyradius(selection='(all)', state=-1, quiet=1):
'''
DESCRIPTION
Radius of gyration
Based on: http://pymolwiki.org/index.php/Radius_of_gyration
SEE ALSO
centerofmass
'''
from chempy import cpv
state, quiet = int(state), int(quiet)
if state < 0:
states = [cmd.get_state()]
elif state == 0:
states = list(range(1, cmd.count_states(selection)+1))
else:
states = [state]
rg_sq_list = []
for state in states:
model = cmd.get_model(selection, state)
x = [i.coord for i in model.atom]
mass = [i.get_mass() * i.q for i in model.atom if i.q > 0]
xm = [cpv.scale(v,m) for v,m in zip(x,mass)]
tmass = sum(mass)
rr = sum(cpv.dot_product(v,vm) for v,vm in zip(x,xm))
mm = sum((sum(i)/tmass)**2 for i in zip(*xm))
rg_sq_list.append(rr/tmass - mm)
rg = (sum(rg_sq_list)/len(rg_sq_list))**0.5
if not quiet:
print(' Radius of gyration: %.2f' % (rg))
return rg
def cafit_orientation(selection, visualize=1, quiet=0):
'''
DESCRIPTION
Get the center and direction of a peptide by least squares
linear fit on CA atoms.
USAGE
cafit_orientation selection [, visualize]
NOTES
Requires python module "numpy".
SEE ALSO
helix_orientation
'''
visualize, quiet = int(visualize), int(quiet)
import numpy
stored.x = list()
cmd.iterate_state(STATE, '(%s) and name CA' % (selection),
'stored.x.append([x,y,z])')
x = numpy.array(stored.x)
U, s, Vh = numpy.linalg.svd(x - x.mean(0))
vec = cpv.normalize(Vh[0])
if cpv.dot_product(vec, x[-1] - x[0]) < 0:
vec = cpv.negate(vec)
return _common_orientation(selection, vec, visualize, quiet)
def cafit_orientation(selection, visualize=1, quiet=0):
'''
DESCRIPTION
Get the center and direction of a peptide by least squares
linear fit on CA atoms.
USAGE
cafit_orientation selection [, visualize]
NOTES
Requires python module "numpy".
SEE ALSO
helix_orientation
'''
visualize, quiet = int(visualize), int(quiet)
import numpy
stored.x = list()
cmd.iterate_state(STATE, '(%s) and name CA' % (selection),
'stored.x.append([x,y,z])')
x = numpy.array(stored.x)
U, s, Vh = numpy.linalg.svd(x - x.mean(0))
vec = cpv.normalize(Vh[0])
if cpv.dot_product(vec, x[-1] - x[0]) < 0:
vec = cpv.negate(vec)
return _common_orientation(selection, vec, visualize, quiet)
def plane_orientation(selection, state=-1, visualize=1, quiet=1):
'''
DESCRIPTION
Fit plane (for example beta-sheet). Can also be used with
angle_between_helices (even though this does not fit helices).
Returns center and normal vector of plane.
'''
try:
import numpy
except ImportError:
print ' Error: numpy not available'
raise CmdException
state, visualize, quiet = int(state), int(visualize), int(quiet)
coords = list()
cmd.iterate_state(state, '(%s) and guide' % (selection),
'coords.append([x,y,z])', space=locals())
if len(coords) < 3:
print 'not enough guide atoms in selection'
raise CmdException
x = numpy.array(coords)
U,s,Vh = numpy.linalg.svd(x - x.mean(0))
# normal vector of plane is 3rd principle component
vec = cpv.normalize(Vh[2])
if cpv.dot_product(vec, x[-1] - x[0]) < 0:
vec = cpv.negate(vec)
center = x.mean(0).tolist()
_common_orientation(selection, center, vec, visualize, 4.0, quiet)
# plane visualize
if visualize:
from pymol import cgo
dir1 = cpv.normalize(Vh[0])
dir2 = cpv.normalize(Vh[1])
sx = [max(i/4.0, 2.0) for i in s]
obj = [ cgo.BEGIN, cgo.TRIANGLES, cgo.COLOR, 0.5, 0.5, 0.5 ]
for vertex in [
cpv.scale(dir1, sx[0]),
cpv.scale(dir2, sx[1]),
cpv.scale(dir2, -sx[1]),
cpv.scale(dir1, -sx[0]),
cpv.scale(dir2, -sx[1]),
cpv.scale(dir2, sx[1]),
]:
obj.append(cgo.VERTEX)
obj.extend(cpv.add(center, vertex))
obj.append(cgo.END)
cmd.load_cgo(obj, cmd.get_unused_name('planeFit'))
return center, vec
def cafit_orientation(selection,
state=STATE,
visualize=1,
guide=1,
quiet=1,
*,
_self=cmd):
'''
DESCRIPTION
Get the center and direction of a peptide by least squares
linear fit on CA atoms.
USAGE
cafit_orientation selection [, visualize ]
NOTES
Requires python module "numpy".
SEE ALSO
helix_orientation
'''
import numpy
state, visualize, quiet = int(state), int(visualize), int(quiet)
if int(guide):
selection = '(%s) and guide' % (selection)
coords = []
_self.iterate_state(state,
selection,
'coords.append([x,y,z])',
space=locals())
x = numpy.array(coords)
center = x.mean(0).tolist()
U, s, Vh = numpy.linalg.svd(x - center)
vec = cpv.normalize(Vh[0])
if cpv.dot_product(vec, x[-1] - x[0]) < 0:
vec = cpv.negate(vec)
_common_orientation(selection,
center,
vec,
visualize,
s[0],
quiet,
_self=_self)
return center, vec
def cafit_orientation(selection, state=STATE, visualize=1, guide=1, quiet=1):
'''
DESCRIPTION
Get the center and direction of a peptide by least squares
linear fit on CA atoms.
USAGE
cafit_orientation selection [, visualize ]
NOTES
Requires python module "numpy".
SEE ALSO
helix_orientation
'''
try:
import numpy
except ImportError:
print ' Error: numpy not available'
raise CmdException
state, visualize, quiet = int(state), int(visualize), int(quiet)
if int(guide):
selection = '(%s) and guide' % (selection)
coords = []
cmd.iterate_state(state, selection,
'coords.append([x,y,z])', space=locals())
x = numpy.array(coords)
center = x.mean(0).tolist()
U,s,Vh = numpy.linalg.svd(x - center)
vec = cpv.normalize(Vh[0])
if cpv.dot_product(vec, x[-1] - x[0]) < 0:
vec = cpv.negate(vec)
_common_orientation(selection, center, vec, visualize, s[0], quiet)
return center, vec
def append_tri(self):
if self.l_vert:
d0 = cpv.sub(self.l_vert[0],self.l_vert[1])
d1 = cpv.sub(self.l_vert[0],self.l_vert[2])
n0 = cpv.cross_product(d0,d1)
n0 = cpv.normalize_failsafe(n0)
if not self.tri_flag:
self.obj.append(BEGIN)
self.obj.append(TRIANGLES)
self.tri_flag = 1
indices = [0, 1, 2]
if not self.l_norm:
# TODO could simplify this if ray tracing would support
# object-level two_sided_lighting. Duplicating the
# face with an offset is a hack and produces visible
# lines on edges.
n1 = [-n0[0],-n0[1],-n0[2]]
ns = cpv.scale(n0,0.002)
indices = [0, 1, 2, 4, 3, 5]
l_vert_offsetted = [cpv.add(v, ns) for v in self.l_vert]
l_vert_offsetted.extend(cpv.sub(v, ns) for v in self.l_vert)
self.l_vert = l_vert_offsetted
self.l_norm = [n0, n0, n0, n1, n1, n1]
elif cpv.dot_product(self.l_norm[0], n0) < 0:
indices = [0, 2, 1]
for i in indices:
self.obj.append(COLOR) # assuming unicolor
self.obj.extend(self.t_colr[i % 3])
self.obj.append(NORMAL)
self.obj.extend(self.l_norm[i])
self.obj.append(VERTEX)
self.obj.extend(self.l_vert[i])
self.l_vert=None
self.t_colr=None
self.l_norm=None
def append_tri(self):
if self.l_vert:
d0 = cpv.sub(self.l_vert[0],self.l_vert[1])
d1 = cpv.sub(self.l_vert[0],self.l_vert[2])
n0 = cpv.cross_product(d0,d1)
n0 = cpv.normalize_failsafe(n0)
if not self.tri_flag:
self.obj.append(BEGIN)
self.obj.append(TRIANGLES)
self.tri_flag = 1
indices = [0, 1, 2]
if not self.l_norm:
# TODO could simplify this if ray tracing would support
# object-level two_sided_lighting. Duplicating the
# face with an offset is a hack and produces visible
# lines on edges.
n1 = [-n0[0],-n0[1],-n0[2]]
ns = cpv.scale(n0,0.002)
indices = [0, 1, 2, 4, 3, 5]
l_vert_offsetted = [cpv.add(v, ns) for v in self.l_vert]
l_vert_offsetted.extend(cpv.sub(v, ns) for v in self.l_vert)
self.l_vert = l_vert_offsetted
self.l_norm = [n0, n0, n0, n1, n1, n1]
elif cpv.dot_product(self.l_norm[0], n0) < 0:
indices = [0, 2, 1]
for i in indices:
self.obj.append(COLOR) # assuming unicolor
self.obj.extend(self.t_colr[i % 3])
self.obj.append(NORMAL)
self.obj.extend(self.l_norm[i])
self.obj.append(VERTEX)
self.obj.extend(self.l_vert[i])
self.l_vert=None
self.t_colr=None
self.l_norm=None
def update_box(self):
if self.points_name in self.cmd.get_names():
model = self.cmd.get_model(self.points_name)
self.coord = (
model.atom[0].coord,
model.atom[1].coord,
model.atom[2].coord,
model.atom[3].coord,
)
p = self.coord[0]
d10 = sub(self.coord[1], p)
d20 = sub(self.coord[2], p)
d30 = sub(self.coord[3], p)
x10_20 = cross_product(d10,d20)
if self.mode != 'quad':
if dot_product(d30,x10_20)<0.0:
p = model.atom[1].coord
d10 = sub(self.coord[0], p)
d20 = sub(self.coord[2], p)
d30 = sub(self.coord[3], p)
n10_20 = normalize(x10_20)
n10 = normalize(d10)
d100 = d10
d010 = remove_component(d20, n10)
if self.mode != 'quad':
d001 = project(d30, n10_20)
else:
d001 = n10_20
n100 = normalize(d100)
n010 = normalize(d010)
n001 = normalize(d001)
f100 = reverse(n100)
f010 = reverse(n010)
f001 = reverse(n001)
if self.mode == 'quad':
p000 = p
p100 = add(p, remove_component(d10,n001))
p010 = add(p, remove_component(d20,n001))
p001 = add(p, remove_component(d30,n001))
else:
p000 = p
p100 = add(p,d100)
p010 = add(p,d010)
p001 = add(p,d001)
p110 = add(p100, d010)
p011 = add(p010, d001)
p101 = add(p100, d001)
p111 = add(p110, d001)
obj = []
if self.mode == 'box': # standard box
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(f001)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p110)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n001)
obj.append(VERTEX); obj.extend(p001)
obj.append(VERTEX); obj.extend(p101)
obj.append(VERTEX); obj.extend(p011)
obj.append(VERTEX); obj.extend(p111)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(f010)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p001)
obj.append(VERTEX); obj.extend(p101)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n010)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p011)
obj.append(VERTEX); obj.extend(p110)
obj.append(VERTEX); obj.extend(p111)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(f100)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p001)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p011)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n100)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p110)
obj.append(VERTEX); obj.extend(p101)
obj.append(VERTEX); obj.extend(p111)
obj.append(END)
model.atom[0].coord = p000
model.atom[1].coord = p100
model.atom[2].coord = add(p010, scale(d100,0.5))
model.atom[3].coord = add(add(p001, scale(d010,0.5)),d100)
elif self.mode=='walls':
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n001)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p110)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n010)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p001)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p101)
obj.append(END)
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n100)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p001)
obj.append(VERTEX); obj.extend(p011)
obj.append(END)
model.atom[0].coord = p000
model.atom[1].coord = p100
model.atom[2].coord = p010
model.atom[3].coord = p001
elif self.mode=='plane':
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n001)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p110)
obj.append(END)
model.atom[0].coord = p000
model.atom[1].coord = p100
model.atom[2].coord = p010
model.atom[3].coord = add(add(p001, scale(d010,0.5)),scale(d100,0.5))
elif self.mode=='quad':
obj.extend([ BEGIN, TRIANGLE_STRIP ])
obj.append(NORMAL); obj.extend(n001)
obj.append(VERTEX); obj.extend(p000)
obj.append(VERTEX); obj.extend(p100)
obj.append(VERTEX); obj.extend(p010)
obj.append(VERTEX); obj.extend(p001)
obj.append(END)
model.atom[0].coord = p000
model.atom[1].coord = p100
model.atom[2].coord = p010
model.atom[3].coord = p001
self.cmd.load_model(model, '_tmp', zoom=0)
self.cmd.update(self.points_name,"_tmp")
self.cmd.delete("_tmp")
# then we load it into PyMOL
self.cmd.delete(self.cgo_name)
self.cmd.load_cgo(obj,self.cgo_name,zoom=0)
self.cmd.order(self.cgo_name+" "+self.points_name,sort=1,location='bottom')
self.cmd.set("nonbonded_size",math.sqrt(dot_product(d10,d10))/10,self.points_name)
def bbPlane(selection='(all)', color='gray', transp=0.3, state=-1, name=None, quiet=1):
"""
DESCRIPTION
Draws a plane across the backbone for a selection
ARGUMENTS
selection = string: protein object or selection {default: (all)}
color = string: color name or number {default: white}
transp = float: transparency component (0.0--1.0) {default: 0.0}
state = integer: object state, 0 for all states {default: 1}
NOTES
You need to pass in an object or selection with at least two
amino acids. The plane spans CA_i, O_i, N-H_(i+1), and CA_(i+1)
"""
from pymol.cgo import BEGIN, TRIANGLES, COLOR, VERTEX, END
from pymol import cgo
from chempy import cpv
# format input
transp = float(transp)
state, quiet = int(state), int(quiet)
if name is None:
name = cmd.get_unused_name("backbonePlane")
if state < 0:
state = cmd.get_state()
elif state == 0:
for state in range(1, cmd.count_states(selection) + 1):
bbPlane(selection, color, transp, state, name, quiet)
return
AAs = []
coords = dict()
# need hydrogens on peptide nitrogen
cmd.h_add('(%s) and n. N' % selection)
# get the list of residue ids
for obj in cmd.get_object_list(selection):
sel = obj + " and (" + selection + ")"
for a in cmd.get_model(sel + " and n. CA", state).atom:
key = '/%s/%s/%s/%s' % (obj, a.segi, a.chain, a.resi)
AAs.append(key)
coords[key] = [a.coord, None, None]
for a in cmd.get_model(sel + " and n. O", state).atom:
key = '/%s/%s/%s/%s' % (obj, a.segi, a.chain, a.resi)
if key in coords:
coords[key][1] = a.coord
for a in cmd.get_model(sel + " and ((n. N extend 1 and e. H) or (r. PRO and n. CD))", state).atom:
key = '/%s/%s/%s/%s' % (obj, a.segi, a.chain, a.resi)
if key in coords:
coords[key][2] = a.coord
# need at least two amino acids
if len(AAs) <= 1:
print("ERROR: Please provide at least two amino acids, the alpha-carbon on the 2nd is needed.")
return
# prepare the cgo
obj = [
BEGIN, TRIANGLES,
COLOR,
]
obj.extend(cmd.get_color_tuple(color))
for res in range(0, len(AAs) - 1):
curIdx, nextIdx = str(AAs[res]), str(AAs[res + 1])
# populate the position array
pos = [coords[curIdx][0], coords[curIdx][1], coords[nextIdx][2], coords[nextIdx][0]]
# if the data are incomplete for any residues, ignore
if None in pos:
if not quiet:
print(' bbPlane: peptide bond %s -> %s incomplete' % (curIdx, nextIdx))
continue
if cpv.distance(pos[0], pos[3]) > 4.0:
if not quiet:
print(' bbPlane: %s and %s not adjacent' % (curIdx, nextIdx))
continue
normal = cpv.normalize(cpv.cross_product(
cpv.sub(pos[1], pos[0]),
cpv.sub(pos[2], pos[0])))
obj.append(cgo.NORMAL)
obj.extend(normal)
# need to order vertices to generate correct triangles for plane
if cpv.dot_product(cpv.sub(pos[0], pos[1]), cpv.sub(pos[2], pos[3])) < 0:
vorder = [0, 1, 2, 2, 3, 0]
else:
vorder = [0, 1, 2, 3, 2, 1]
# fill in the vertex data for the triangles;
for i in vorder:
obj.append(VERTEX)
obj.extend(pos[i])
# finish the CGO
obj.append(END)
# update the UI
cmd.load_cgo(obj, name, state, zoom=0)
cmd.set("cgo_transparency", transp, name)
def plane_orientation(selection, state=STATE, visualize=1, guide=0, quiet=1):
'''
DESCRIPTION
Fit plane (for example beta-sheet). Can also be used with
angle_between_helices (even though this does not fit helices).
Returns center and normal vector of plane.
'''
try:
import numpy
except ImportError:
print(' Error: numpy not available')
raise CmdException
state, visualize, quiet = int(state), int(visualize), int(quiet)
if int(guide):
selection = '(%s) and guide' % (selection)
coords = list()
cmd.iterate_state(state,
selection,
'coords.append([x,y,z])',
space=locals())
if len(coords) < 3:
print('not enough guide atoms in selection')
raise CmdException
x = numpy.array(coords)
U, s, Vh = numpy.linalg.svd(x - x.mean(0))
# normal vector of plane is 3rd principle component
vec = cpv.normalize(Vh[2])
if cpv.dot_product(vec, x[-1] - x[0]) < 0:
vec = cpv.negate(vec)
center = x.mean(0).tolist()
_common_orientation(selection, center, vec, visualize, 4.0, quiet)
# plane visualize
if visualize:
from pymol import cgo
dir1 = cpv.normalize(Vh[0])
dir2 = cpv.normalize(Vh[1])
sx = [max(i / 4.0, 2.0) for i in s]
obj = [cgo.BEGIN, cgo.TRIANGLES, cgo.COLOR, 0.5, 0.5, 0.5]
for vertex in [
cpv.scale(dir1, sx[0]),
cpv.scale(dir2, sx[1]),
cpv.scale(dir2, -sx[1]),
cpv.scale(dir1, -sx[0]),
cpv.scale(dir2, -sx[1]),
cpv.scale(dir2, sx[1]),
]:
obj.append(cgo.VERTEX)
obj.extend(cpv.add(center, vertex))
obj.append(cgo.END)
cmd.load_cgo(obj, get_unused_name('planeFit'))
return center, vec