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IMP Reference Guide
2.21.0
The Integrative Modeling Platform
IMP Manual
Reference Guide
Tutorial Index
Modules
Classes
Examples
version 2.21.0
core/pair_restraint.py
Restrain the distance between a pair of particles.
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## \example core/pair_restraint.py
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# Restrain the distance between a pair of particles.
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#
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5
import
IMP.algebra
6
import
IMP.core
7
import
sys
8
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IMP.setup_from_argv
(sys.argv,
"pair restraint"
)
10
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# Make two xyz particles randomly distributed in space
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m =
IMP.Model
()
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b =
IMP.algebra.BoundingBox3D
(
IMP.algebra.Vector3D
(0,0,0),
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IMP.algebra.Vector3D
(10,10,10))
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inds = []
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for
i
in
range(2):
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p = m.add_particle(
"p"
)
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d =
IMP.core.XYZR.setup_particle
(m, p,
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IMP.algebra.Sphere3D
(
IMP.algebra.get_random_vector_in
(b), 1))
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inds.append(p)
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# Score the distance between the two particles with a harmonic function
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uf =
IMP.core.Harmonic
(0, 1)
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df =
IMP.core.DistancePairScore
(uf)
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r =
IMP.core.PairRestraint
(m, df, (inds[0], inds[1]))
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# Print the current score of the restraint, without first derivatives
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print(r.evaluate(
False
))