# Source code for pygeo.parameterization.DVGeoVSP

```
# ======================================================================
# Imports
# ======================================================================
from collections import OrderedDict
import time
import numpy as np
from mpi4py import MPI
from baseclasses.utils import Error
from .DVGeoSketch import DVGeoSketch
from pyspline.utils import searchQuads
from .designVars import vspDV
# openvsp python interface
try:
import openvsp
except ImportError:
try:
import vsp as openvsp
except ImportError:
raise ImportError("The OpenVSP Python API is required in order to use DVGeometryVSP")
# make sure volume projection api is available
try:
openvsp.CompPntRST
except AttributeError:
raise ImportError(
"Out of date version of OpenVSP detected." "OpenVSP 3.28.0 or greater is required in order to use DVGeometryVSP"
)
[docs]class DVGeometryVSP(DVGeoSketch):
"""
A class for manipulating OpenVSP geometry.
The purpose of the DVGeometryVSP class is to provide translation of the VSP geometry engine to externally supplied surfaces.
This allows the use of VSP design variables to control the MACH framework.
There are several important limitations:
#. Since VSP is volume-based, it cannot be used to parameterize a geometry that does not lie within a VSP body.
#. It cannot handle *moving* intersections. A geometry with static intersections is fine as long as the intersection doesn't move
#. It does not support complex numbers for the complex-step method.
#. It does not support separate configurations.
#. Because OpenVSP does not provide sensitivities, this class uses parallel finite differencing to obtain the required Jacobian matrices.
Parameters
----------
fileName : str
filename of .vsp3 file.
comm : MPI Intra Comm
Comm on which to build operate the object. This is used to
perform embarrassingly parallel finite differencing. Defaults to
MPI.COMM_WORLD.
scale : float
A global scale factor from the VSP geometry to incoming (CFD) mesh
geometry. For example, if the VSP model is in inches, and the CFD
in meters, scale=0.0254.
comps : list of strings
A list of string defining the subset of the VSP components to use when
exporting the P3D surface files
Examples
--------
The general sequence of operations for using DVGeometry is as follows:
>>> from pygeo import *
>>> DVGeo = DVGeometryVSP("wing.vsp3", MPI_COMM_WORLD)
>>> # Add a set of coordinates Xpt into the object
>>> DVGeo.addPointSet(Xpt, 'myPoints')
>>>
"""
def __init__(self, fileName, comm=MPI.COMM_WORLD, scale=1.0, comps=[], projTol=0.01):
if comm.rank == 0:
print("Initializing DVGeometryVSP")
t0 = time.time()
super().__init__(fileName=fileName, comm=comm, scale=scale, projTol=projTol)
self.exportComps = []
# Clear the vsp model
openvsp.ClearVSPModel()
t1 = time.time()
# read the model
openvsp.ReadVSPFile(fileName)
t2 = time.time()
if self.comm.rank == 0:
print("Loading the vsp model took:", (t2 - t1))
# List of all components returned from VSP. Note that this
# order is important. It is the order that we use to map the
# actual geom_id by using the geom_names
allComps = openvsp.FindGeoms()
allNames = []
for c in allComps:
allNames.append(openvsp.GetContainerName(c))
if not comps:
# no components specified, we use all
self.allComps = allComps[:]
else:
# we get the vsp comp IDs from the comps list
self.allComps = []
for c in comps:
self.allComps.append(allComps[allNames.index(c)])
# we need the names and bounding boxes of components
self.compNames = []
self.bbox = OrderedDict()
self.bboxuv = self._getuv()
for c in self.allComps:
self.compNames.append(openvsp.GetContainerName(c))
self.bbox[c] = self._getBBox(c)
# Now, we need to form our own quad meshes for fast projections
if comm.rank == 0:
print("Building a quad mesh for fast projections.")
self._getQuads()
if comm.rank == 0:
t3 = time.time()
print("Initialized DVGeometry VSP in", (t3 - t0), "seconds.")
[docs] def addPointSet(self, points, ptName, **kwargs):
"""
Add a set of coordinates to DVGeometry
The is the main way that geometry, in the form of a coordinate
list is given to DVGeometry to be manipulated.
Parameters
----------
points : array, size (N,3)
The coordinates to embed. These coordinates *should* all
project into the interior of the FFD volume.
ptName : str
A user supplied name to associate with the set of
coordinates. Thisname will need to be provided when
updating the coordinates or when getting the derivatives
of the coordinates.
Returns
-------
dMax_global : float
The maximum distance betwen the points added and the
projection on the VSP surfaces on any processor.
"""
self.ptSetNames.append(ptName)
# save this name so that we can zero out the jacobians properly
# ADFlow checks self.points to see if something is added or not.
self.points[ptName] = True
points = np.array(points).real.astype("d")
# we need to project each of these points onto the VSP geometry,
# get geometry and surface IDs, u, v values, and coordinates of the projections.
# then calculate the self.offset variable using the projected points.
# first, to get a good initial guess on the geometry and u,v values,
# we can use the adt projections in pyspline
if len(points) > 0:
# faceID has the index of the corresponding quad element.
# uv has the parametric u and v weights of the projected point.
faceID, uv = searchQuads(self.pts0.T, (self.conn + 1).T, points.T)
uv = uv.T
faceID -= 1 # Convert back to zero-based indexing.
# after this point we should have the projected points.
else:
faceID = np.zeros((0), "intc")
uv = np.zeros((0, 2), "intc")
# now we need to figure out which surfaces the points got projected to
# From the faceID we can back out what component each one is
# connected to. This way if we have intersecting components we
# only change the ones that are apart of the two surfaces.
cumFaceSizes = np.zeros(len(self.sizes) + 1, "intc")
for i in range(len(self.sizes)):
nCellI = self.sizes[i][0] - 1
nCellJ = self.sizes[i][1] - 1
cumFaceSizes[i + 1] = cumFaceSizes[i] + nCellI * nCellJ
compIDs = np.searchsorted(cumFaceSizes, faceID, side="right") - 1
# coordinates to store the projected points
pts = np.zeros(points.shape)
# npoints * 3 list containing the geomID, u and v values
# this can be improved if we can group points that get
# projected to the same geometry.
npoints = len(points)
geom = np.zeros(npoints, dtype="intc")
r = np.zeros(npoints)
s = np.zeros(npoints)
t = np.zeros(npoints)
# initialize one 3dvec for projections
pnt = openvsp.vec3d()
# Keep track of the largest distance between cfd and vsp surfaces
dMax = 1e-16
t1 = time.time()
for i in range(points.shape[0]):
# this is the geometry our point got projected to in the adt code
gind = compIDs[i] # index
gid = self.allComps[gind] # ID
# set the coordinates of the point object
pnt.set_xyz(points[i, 0] * self.meshScale, points[i, 1] * self.meshScale, points[i, 2] * self.meshScale)
# first, we call the fast projection code with the initial guess to find the nearest point on the surface
# this is the global index of the first node of the projected element
nodeInd = self.conn[faceID[i], 0]
# get the local index of this node
nn = nodeInd - self.cumSizes[gind]
# figure out the i and j indices of the first point of the element
# we projected this point to
ii = np.mod(nn, self.sizes[gind, 0])
jj = np.floor_divide(nn, self.sizes[gind, 0])
# calculate the global u and v change in this element
du = self.uv[gind][0][ii + 1] - self.uv[gind][0][ii]
dv = self.uv[gind][1][jj + 1] - self.uv[gind][1][jj]
# now get this points u,v coordinates on the vsp geometry and add
# compute the initial guess using the tesselation data of the surface
ug = uv[i, 0] * du + self.uv[gind][0][ii]
vg = uv[i, 1] * dv + self.uv[gind][1][jj]
# We now convert the surface parameteric variables (u,v) to their equivalent volume parameterization (r,s,t)
# this will serve as our initial guess for the volume projection procedure
# In general, the conversion between the surface parametric coordinates (u, v)
# and the first two volume parameteric coordinate (r, s)
# are given by the equations below:
# u = r
# v_low = s
# v_upper = 1 - s
# The 3rd parameteric coordinate interpolates between the the upper and lower surfaces
# X(r,s,t) = t * X_upper(r, s) + (1 - t) * X_lower(r, s)
rg = ug
if vg < 0.5:
# This point is on the lower surface
sg = vg
else:
# This point is on the upper surface
sg = 1.0 - vg
# tg = 0.5 places the initial guess in the middle of the upper and lower surfaces for the volume
# Note: If the point we're looking for actually lies on the surface openvsp's
# projection algorithm (FindRSTGuess) will still quickly locate it, since our volume interpolation
# is linear through the depth (i.e. in t)
tg = 0.5
# Now, find the closest volume projection
d, r[i], s[i], t[i] = openvsp.FindRSTGuess(gid, 0, pnt, rg, sg, tg)
geom[i] = gind
# if we dont have a good projection, try projecting again to surfaces
# with the slow code.
if d > self.projTol:
# print('Guess code failed with projection distance',d)
# for now, we need to check for all geometries separately.
# Just pick the one that yields the smallest d
gind = 0
for gid in self.allComps:
# only project if the point is in the bounding box of the geometry
if (
(self.bbox[gid][0, 0] < points[i, 0] < self.bbox[gid][0, 1])
and (self.bbox[gid][1, 0] < points[i, 1] < self.bbox[gid][1, 1])
and (self.bbox[gid][2, 0] < points[i, 2] < self.bbox[gid][2, 1])
):
# project the point onto the VSP geometry
dNew, rout, sout, tout = openvsp.FindRST(gid, 0, pnt)
# check if we are closer
if dNew < d:
# save this info if we found a closer projection
r[i] = rout
s[i] = sout
t[i] = tout
geom[i] = gind
d = dNew
gind += 1
# check if the final d is larger than our previous largest value
dMax = max(d, dMax)
# We need to evaluate this pnt to get its coordinates in physical space
pnt = openvsp.CompPntRST(self.allComps[geom[i]], 0, r[i], s[i], t[i])
pts[i, 0] = pnt.x() * self.modelScale
pts[i, 1] = pnt.y() * self.modelScale
pts[i, 2] = pnt.z() * self.modelScale
# some debug info
dMax_global = self.comm.allreduce(dMax, op=MPI.MAX)
t2 = time.time()
if self.comm.rank == 0 or self.comm is None:
print("DVGeometryVSP note:\nAdding pointset", ptName, "took", t2 - t1, "seconds.")
print("Maximum distance between the added points and the VSP geometry is", dMax_global)
# Create the little class with the data
self.pointSets[ptName] = PointSet(points, pts, geom, r, s, t)
# Set the updated flag to false because the jacobian is not up to date.
self.updated[ptName] = False
self.updatedJac[ptName] = False
return dMax_global
[docs] def setDesignVars(self, dvDict):
"""
Standard routine for setting design variables from a design
variable dictionary.
Parameters
----------
dvDict : dict
Dictionary of design variables. The keys of the dictionary
must correspond to the design variable names. Any
additional keys in the dv-dictionary are simply ignored.
"""
# Just dump in the values
for key in dvDict:
if key in self.DVs:
self.DVs[key].value = dvDict[key]
# we just need to set the design variables in the VSP model and we are done
self._updateModel()
# update the projected coordinates
self._updateProjectedPts()
# Flag all the pointSets as not being up to date:
for pointSet in self.updated:
self.updated[pointSet] = False
# set the jacobian flag to false
for ptName in self.pointSets:
self.updatedJac[ptName] = False
[docs] def update(self, ptSetName, config=None):
"""
This is the main routine for returning coordinates that have been
updated by design variables. Multiple configs are not
supported.
Parameters
----------
ptSetName : str
Name of point-set to return. This must match ones of the
given in an :func:`addPointSet()` call.
config : str or list
Inactive parameter for DVGeometryVSP.
See the same method in DVGeometry.py for its normal use.
"""
# new cfd point coordinates are the updated projections minus the offset
newPts = self.pointSets[ptSetName].pts - self.pointSets[ptSetName].offset
# Finally flag this pointSet as being up to date:
self.updated[ptSetName] = True
return newPts
[docs] def writeVSPFile(self, fileName, exportSet=0):
"""
Take the current design and write a new VSP file
Parameters
----------
fileName : str
Name of the output VSP file
exportSet : int
optional input parameter to select an export set in VSP
"""
openvsp.WriteVSPFile(fileName, exportSet)
[docs] def getNDV(self):
"""
Return the number of DVs
Returns
-------
len(self.DVs) : int
number of design variables
"""
return len(self.DVs)
[docs] def totalSensitivity(self, dIdpt, ptSetName, comm=None, config=None):
r"""
This function computes sensitivity information.
Specifically, it computes the following:
:math:`\frac{dX_{pt}}{dX_{DV}}^T \frac{dI}{d_{pt}}`
Parameters
----------
dIdpt : array of size (Npt, 3) or (N, Npt, 3)
This is the total derivative of the objective or function
of interest with respect to the coordinates in
'ptSetName'. This can be a single array of size (Npt, 3)
**or** a group of N vectors of size (Npt, 3, N). If you
have many to do, it is faster to do many at once.
ptSetName : str
The name of set of points we are dealing with
comm : MPI.IntraComm
The communicator to use to reduce the final derivative. If
comm is None, no reduction takes place.
Returns
-------
dIdxDict : dict
The dictionary containing the derivatives, suitable for
pyOptSparse
"""
# We may not have set the variables so the surf jac might not be computed.
if self.pointSets[ptSetName].jac is None:
# in this case, we updated our pts when we added our pointset,
# therefore the reference pts are up to date.
self._computeSurfJacobian()
# if the jacobian for this pointset is not up to date
# update all the points
if not self.updatedJac[ptSetName]:
self._computeSurfJacobian()
# The following code computes the final sensitivity product:
#
# T T
# pXpt pI
# ------ ------
# pXdv pXpt
#
# Where I is the objective, Xpt are the externally coordinates
# supplied in addPointSet
# Make dIdpt at least 3D
if len(dIdpt.shape) == 2:
dIdpt = np.array([dIdpt])
# reshape the dIdpt array from [N] * [nPt] * [3] to [N] * [nPt*3]
dIdpt = dIdpt.reshape((dIdpt.shape[0], dIdpt.shape[1] * 3))
# jacobian of the projected points
jac = self.pointSets[ptSetName].jac
# local product
dIdxT_local = jac.T.dot(dIdpt.T)
# take the transpose to get the jacobian itself dI/dx
dIdx_local = dIdxT_local.T
# sum the results if we are provided a comm
if comm:
dIdx = comm.allreduce(dIdx_local, op=MPI.SUM)
else:
dIdx = dIdx_local
# Now convert to dict:
dIdxDict = {}
i = 0
for dvName in self.DVs:
dIdxDict[dvName] = np.array(dIdx[:, i]).T
i += 1
return dIdxDict
[docs] def totalSensitivityProd(self, vec, ptSetName, comm=None, config=None):
r"""
This function computes sensitivity information.
Specifically, it computes the following:
:math:`\frac{dX_{pt}}{dX_{DV}} \ vec`
This is useful for forward AD mode.
Parameters
----------
vec : dictionary whose keys are the design variable names, and whose
values are the derivative seeds of the corresponding design variable.
ptSetName : str
The name of set of points we are dealing with
comm : MPI.IntraComm
inactive parameter, this has no effect on the final result
because with this method, the reduction is performed externally
Returns
-------
xsdot : array (Nx3) -> Array with derivative seeds of the surface nodes.
"""
# We may not have set the variables so the surf jac might not be computed.
if self.pointSets[ptSetName].jac is None:
# in this case, we updated our pts when we added our pointset,
# therefore the reference pts are up to date.
self._computeSurfJacobian()
# if the jacobian for this pointset is not up to date
# update all the points
if not self.updatedJac[ptSetName]:
self._computeSurfJacobian()
# vector that has all the derivative seeds of the design vars
newvec = np.zeros(self.getNDV())
# populate newvec
for i, dv in enumerate(self.DVs):
if dv in vec:
newvec[i] = vec[dv]
# we need to multiply with the surface jacobian
dPt = self.pointSets[ptSetName].jac.dot(newvec)
return dPt
[docs] def totalSensitivityTransProd(self, dIdpt, ptSetName, comm=None, config=None):
r"""
This function computes sensitivity information.
Specifically, it computes the following:
:math:`\frac{dX_{pt}}{dX_{DV}}^T \frac{dI}{d_{pt}}`
Parameters
----------
dIdpt : array of size (Npt, 3) or (N, Npt, 3)
This is the total derivative of the objective or function
of interest with respect to the coordinates in
'ptSetName'. This can be a single array of size (Npt, 3)
**or** a group of N vectors of size (Npt, 3, N). If you
have many to do, it is faster to do many at once.
ptSetName : str
The name of set of points we are dealing with
comm : MPI.IntraComm
The communicator to use to reduce the final derivative. If
comm is None, no reduction takes place.
Returns
-------
dIdxDict : dic
The dictionary containing the derivatives, suitable for
pyOptSparse
"""
# We may not have set the variables so the surf jac might not be computed.
if self.pointSets[ptSetName].jac is None:
# in this case, we updated our pts when we added our pointset,
# therefore the reference pts are up to date.
self._computeSurfJacobian()
# if the jacobian for this pointset is not up to date
# update all the points
if not self.updatedJac[ptSetName]:
self._computeSurfJacobian()
# The following code computes the final sensitivity product:
#
# T T
# pXpt pI
# ------ ------
# pXdv pXpt
#
# Where I is the objective, Xpt are the externally coordinates
# supplied in addPointSet
# Make dIdpt at least 3D
if len(dIdpt.shape) == 2:
dIdpt = np.array([dIdpt])
# reshape the dIdpt array from [N] * [nPt] * [3] to [N] * [nPt*3]
dIdpt = dIdpt.reshape((dIdpt.shape[0], dIdpt.shape[1] * 3))
jac = self.pointSets[ptSetName].jac.copy()
dIdxT_local = jac.T.dot(dIdpt.T)
dIdx_local = dIdxT_local.T
if comm:
dIdx = comm.allreduce(dIdx_local, op=MPI.SUM)
else:
dIdx = dIdx_local
# Now convert to dict:
dIdxDict = {}
i = 0
for dvName in self.DVs:
dIdxDict[dvName] = np.array(dIdx[:, i]).T
i += 1
return dIdxDict
[docs] def addVariable(
self, component, group, parm, value=None, lower=None, upper=None, scale=1.0, scaledStep=True, dh=1e-6
):
"""
Add a design variable definition.
Parameters
----------
component : str
Name of the VSP component
group : str
Name of the VSP group
parm : str
Name of the VSP parameter
value : float or None
The design variable. If this value is not supplied (None), then
the current value in the VSP model will be queried and used
lower : float or None
Lower bound for the design variable. Use None for no lower bound
upper : float or None
Upper bound for the design variable. Use None for no upper bound
scale : float
Scale factor
scaledStep : bool
Flag to use a scaled step sized based on the initial value of the
variable. It will remain constant thereafter.
dh : float
Step size. When scaledStep is True, the actual step is dh*value. Otherwise
this actual step is used.
"""
container_id = openvsp.FindContainer(component, 0)
if container_id == "":
raise Error("Bad component for DV: %s" % component)
parm_id = openvsp.FindParm(container_id, parm, group)
if parm_id == "":
raise Error(f"Bad group or parm: {component} {group} {parm}")
# Now we know the parmID is ok. So we just get the value
val = openvsp.GetParmVal(parm_id)
dvName = f"{component}:{group}:{parm}"
if value is None:
value = val
if scaledStep:
dh = dh * value
if value == 0:
raise Error(
"Initial value is exactly 0. scaledStep option cannot be used"
"Specify an explicit dh with scaledStep=False"
)
self.DVs[dvName] = vspDV(parm_id, dvName, component, group, parm, value, lower, upper, scale, dh)
[docs] def printDesignVariables(self):
"""
Print a formatted list of design variables to the screen
"""
print("-" * 85)
print("{:>30}{:>20}{:>20}{:>15}".format("Component", "Group", "Parm", "Value"))
print("-" * 85)
for dvName in self.DVs:
DV = self.DVs[dvName]
print(f"{DV.component:>30}{DV.group:>20}{DV.parm:>20}{float(DV.value):15g}")
[docs] def createDesignFile(self, fileName):
"""
Take the current set of design variables and create a .des file
Parameters
----------
fileName : str
name of the output .des file
"""
f = open(fileName, "w")
f.write("%d\n" % len(self.DVs))
for dvName in self.DVs:
DV = self.DVs[dvName]
f.write(f"{DV.parmID}:{DV.component}:{DV.group}:{DV.parm}:{float(DV.value):20.15g}\n")
f.close()
[docs] def writePlot3D(self, fileName, exportSet=0):
"""
Write the current design to Plot3D file
Parameters
----------
fileName : str
name of the output Plot3D file
exportSet : int
optional argument to specify the export set in VSP
"""
for dvName in self.DVs:
DV = self.DVs[dvName]
# We use float here since sometimes pyOptsparse will give
# stupid numpy zero-dimensional arrays, which swig does
# not like.
openvsp.SetParmVal(DV.parmID, float(DV.value))
openvsp.Update()
# First set the export flag for exportSet to False for everyone
for comp in self.allComps:
openvsp.SetSetFlag(comp, exportSet, False)
for comp in self.allComps:
# Check if this one is in our list:
compName = openvsp.GetContainerName(comp)
if compName in self.compNames:
openvsp.SetSetFlag(comp, exportSet, True)
self.exportComps.append(compName)
# Write the export file.
openvsp.ExportFile(fileName, exportSet, openvsp.EXPORT_PLOT3D)
# ----------------------------------------------------------------------- #
# THE REMAINDER OF THE FUNCTIONS NEED NOT BE CALLED BY THE USER #
# ----------------------------------------------------------------------- #
def _updateModel(self):
"""
Set each of the DVs. We have the parmID stored so it's easy.
"""
for dvName in self.DVs:
DV = self.DVs[dvName]
# for angle parameters, vsp only takes in degrees between -180 and +180,
# which creates an unnecessary discontinuity at +-180.
# to fix this, we take the mod of the value and set it to the correct range
# that is allowed by VSP. Because all of the FD jacobian routine also goes
# through here to update the model, we effectively maintain consistency
if "angle" in DV.parm.lower():
# set this new value separately to leave the DV.value itself untouched
new_value = ((DV.value + 180.0) % 360.0) - 180.0
openvsp.SetParmVal(DV.parmID, float(new_value))
else:
# We use float here since sometimes pyOptsparse will give
# numpy zero-dimensional arrays, which swig does not like
openvsp.SetParmValUpdate(DV.parmID, float(DV.value))
# update the model
openvsp.Update()
def _updateProjectedPts(self):
"""
Internally updates the coordinates of the projected points.
"""
for ptSetName in self.pointSets:
# get the current coordinates of projection points
n = len(self.pointSets[ptSetName].points)
newPts = np.zeros((n, 3))
# newPts should get the new projected coords
# get the info
geom = self.pointSets[ptSetName].geom
r = self.pointSets[ptSetName].r
s = self.pointSets[ptSetName].s
t = self.pointSets[ptSetName].t
# This can all be done with arrays if we group points wrt geometry
for i in range(n):
# evaluate the new projected point coordinates
pnt = openvsp.CompPntRST(self.allComps[geom[i]], 0, r[i], s[i], t[i])
# update the coordinates
newPts[i, :] = (pnt.x(), pnt.y(), pnt.z())
# scale vsp coordinates to mesh coordinates, do it safely above for now
newPts *= self.modelScale
# set the updated coordinates
self.pointSets[ptSetName].pts = newPts
def _getBBox(self, comp):
"""
This function computes the bounding box of the component. We add some buffer on each
direction because we will use this bbox to determine which components to project points
while adding point sets.
"""
# initialize the array
bbox = np.zeros((3, 2))
# we need to get the number of main surfaces on this geometry
nSurf = openvsp.GetNumMainSurfs(comp)
nuv = self.bboxuv.shape[0]
# allocate the arrays
nodes = np.zeros((nSurf * nuv, 3))
# loop over the surfaces
for iSurf in range(nSurf):
offset = iSurf * nuv
# evaluate the points
ptVec = openvsp.CompVecPnt01(comp, iSurf, self.bboxuv[:, 0], self.bboxuv[:, 1])
# now extract the coordinates from the vec3dvec...sigh...
for i in range(nuv):
nodes[offset + i, :] = (ptVec[i].x(), ptVec[i].y(), ptVec[i].z())
# get the min/max values of the coordinates
for i in range(3):
# this might be faster if we specify row/column major
bbox[i, 0] = nodes[:, i].min()
bbox[i, 1] = nodes[:, i].max()
# finally scale the bounding box and return
bbox *= self.modelScale
# also give some offset on all directions
bbox[:, 0] -= 0.1
bbox[:, 1] += 0.1
return bbox.copy()
def _getuv(self):
"""
Creates a uniform array of u-v combinations so that we can build a quad mesh ourselves.
"""
# we need to sample the geometry, just do uniformly now
nu = 20
nv = 20
# define the points on the parametric domain to sample
ul = np.linspace(0, 1, nu + 1)
vl = np.linspace(0, 1, nv + 1)
uu, vv = np.meshgrid(ul, vl)
uu = uu.flatten()
vv = vv.flatten()
# now create a concentrated uv array
uv = np.dstack((uu, vv)).squeeze()
return uv.copy()
def _computeSurfJacobian(self):
"""
This routine comptues the jacobian of the VSP surface with respect
to the design variables. Since our point sets are rigidly linked to
the VSP projection points, this is all we need to calculate. The input
pointSets is a list or dictionary of pointSets to calculate the jacobian for.
this routine runs in parallel, so it is important that any call leading to this
subroutine is performed synchronously among self.comm
VSP has a bug they refuse to fix. In a non-deterministic way, the spanwise u-v
mapping can differ from run to run. Seems like there are two modes. The differences
are small, but if we end up doing the FD with results from another processor
the difference is large enough to completely mess up the sensitivity. Due to this
we compute both baseline point and perturbed point on the processor that perturbs a given DV
this is slightly slower but avoids this issue. the final gradient has some error still,
but much more managable and unimportant compared to errors introduced by FD itself.
See issue https://github.com/mdolab/pygeo/issues/58 for updates.
"""
# timing stuff:
t1 = time.time()
tvsp = 0
teval = 0
tcomm = 0
# counts
nDV = self.getNDV()
dvKeys = list(self.DVs.keys())
nproc = self.comm.size
rank = self.comm.rank
# arrays to collect local pointset info
rl = np.zeros(0)
sl = np.zeros(0)
tl = np.zeros(0)
gl = np.zeros(0, dtype="intc")
for ptSetName in self.pointSets:
# initialize the Jacobians
self.pointSets[ptSetName].jac = np.zeros((3 * self.pointSets[ptSetName].nPts, nDV))
# first, we need to vstack all the point set info we have
# counts of these are also important, saved in ptSet.nPts
rl = np.concatenate((rl, self.pointSets[ptSetName].r))
sl = np.concatenate((sl, self.pointSets[ptSetName].s))
tl = np.concatenate((tl, self.pointSets[ptSetName].t))
gl = np.concatenate((gl, self.pointSets[ptSetName].geom))
# now figure out which proc has how many points.
sizes = np.array(self.comm.allgather(len(rl)), dtype="intc")
# displacements for allgather
disp = np.array([np.sum(sizes[:i]) for i in range(nproc)], dtype="intc")
# global number of points
nptsg = np.sum(sizes)
# create a local new point array. We will use this to get the new
# coordinates as we perturb DVs. We just need one (instead of nDV times the size)
# because we get the new points, calculate the jacobian and save it right after
ptsNewL = np.zeros(len(rl) * 3)
# create the arrays to receive the global info
rg = np.zeros(nptsg)
sg = np.zeros(nptsg)
tg = np.zeros(nptsg)
gg = np.zeros(nptsg, dtype="intc")
# Now we do an allGatherv to get a long list of all pointset information
self.comm.Allgatherv([rl, len(rl)], [rg, sizes, disp, MPI.DOUBLE])
self.comm.Allgatherv([sl, len(sl)], [sg, sizes, disp, MPI.DOUBLE])
self.comm.Allgatherv([tl, len(tl)], [tg, sizes, disp, MPI.DOUBLE])
self.comm.Allgatherv([gl, len(gl)], [gg, sizes, disp, MPI.INT])
# we now have all the point info on all procs.
tcomm += time.time() - t1
# We need to evaluate all the points on respective procs for FD computations
# allocate memory
pts0 = np.zeros((nptsg, 3))
# evaluate the points
for j in range(nptsg):
pnt = openvsp.CompPntRST(self.allComps[gg[j]], 0, rg[j], sg[j], tg[j])
pts0[j, :] = (pnt.x(), pnt.y(), pnt.z())
# determine how many DVs this proc will perturb.
n = 0
for iDV in range(len(dvKeys)):
# I have to do this one.
if iDV % nproc == rank:
n += 1
# allocate the approriate sized numpy array for the perturbed points
ptsNew = np.zeros((n, nptsg, 3))
# perturb the DVs on different procs and compute the new point coordinates.
i = 0 # Counter on local Jac
for iDV in range(len(dvKeys)):
# I have to do this one.
if iDV % nproc == rank:
# Step size for this particular DV
dh = self.DVs[dvKeys[iDV]].dh
# Perturb the DV
dvSave = self.DVs[dvKeys[iDV]].value.copy()
self.DVs[dvKeys[iDV]].value += dh
# update the vsp model
t11 = time.time()
self._updateModel()
t12 = time.time()
tvsp += t12 - t11
t11 = time.time()
# evaluate the points
for j in range(nptsg):
pnt = openvsp.CompPntRST(self.allComps[gg[j]], 0, rg[j], sg[j], tg[j])
ptsNew[i, j, :] = (pnt.x(), pnt.y(), pnt.z())
t12 = time.time()
teval += t12 - t11
# now we can calculate the jac and put it back in ptsNew
ptsNew[i, :, :] = (ptsNew[i, :, :] - pts0[:, :]) / dh
# Reset the DV
self.DVs[dvKeys[iDV]].value = dvSave.copy()
# increment the counter
i += 1
# scale the points
ptsNew *= self.modelScale
# Now, we have perturbed points on each proc that perturbed a DV
# reset the model.
t11 = time.time()
self._updateModel()
t12 = time.time()
tvsp += t12 - t11
ii = 0
# loop over the DVs and scatter the perturbed points to original procs
for iDV in range(len(dvKeys)):
# Step size for this particular DV
dh = self.DVs[dvKeys[iDV]].dh
t11 = time.time()
# create the send/recv buffers for the scatter
if iDV % nproc == rank:
sendbuf = [ptsNew[ii, :, :].flatten(), sizes * 3, disp * 3, MPI.DOUBLE]
else:
sendbuf = [np.zeros((0, 3)), sizes * 3, disp * 3, MPI.DOUBLE]
recvbuf = [ptsNewL, MPI.DOUBLE]
# scatter the info from the proc that perturbed this DV to all procs
self.comm.Scatterv(sendbuf, recvbuf, root=(iDV % nproc))
t12 = time.time()
tcomm += t12 - t11
# calculate the jacobian here for the pointsets
offset = 0
for ptSet in self.pointSets:
# number of points in this pointset
nPts = self.pointSets[ptSet].nPts
# indices to extract correct points from the long pointset array
ibeg = offset * 3
iend = ibeg + nPts * 3
# ptsNewL has the jacobian itself...
self.pointSets[ptSet].jac[0 : nPts * 3, iDV] = ptsNewL[ibeg:iend].copy()
# TODO when OpenVSP fixes the bug in spanwise u-v distribution, we can disable the line above and
# go back to the proper way below. we also need to clean up the evaluations themselves
# self.pointSets[ptSet].jac[0:nPts*3, iDV] = (ptsNewL[ibeg:iend] - self.pointSets[ptSet].pts.flatten())/dh
# increment the offset
offset += nPts
# pertrub the local counter on this proc.
# This loops over the DVs that this proc perturbed
if iDV % nproc == rank:
ii += 1
t2 = time.time()
if rank == 0:
print("FD jacobian calcs with dvgeovsp took", (t2 - t1), "seconds in total")
print("updating the vsp model took", tvsp, "seconds")
print("evaluating the new points took", teval, "seconds")
print("communication took", tcomm, "seconds")
# set the update flags
for ptSet in self.pointSets:
self.updatedJac[ptSet] = True
def _getQuads(self):
# build the quad mesh using the internal vsp geometry
nSurf = len(self.allComps)
pts = np.zeros((0, 3))
conn = np.zeros((0, 4), dtype="intc")
sizes = np.zeros((nSurf, 2), "intc")
cumSizes = np.zeros(nSurf + 1, "intc")
uv = [] # this will hold tessalation points
offset = 0
gind = 0
for geom in self.allComps:
# get uv tesselation
utess, wtess = openvsp.GetUWTess01(geom, 0)
# check if these values are good, otherwise, do it yourself!
# save these values
uv.append([np.array(utess), np.array(wtess)])
nu = len(utess)
nv = len(wtess)
nElem = (nu - 1) * (nv - 1)
# get u,v combinations of nodes
uu, vv = np.meshgrid(utess, wtess)
utess = uu.flatten()
wtess = vv.flatten()
# get the points
ptvec = openvsp.CompVecPnt01(geom, 0, utess, wtess)
# number of nodes for this geometry
curSize = len(ptvec)
# initialize coordinate and connectivity arrays
compPts = np.zeros((curSize, 3))
compConn = np.zeros((nElem, 4), dtype="intc")
# get the coordinates of the points
for i in range(curSize):
compPts[i, :] = (ptvec[i].x(), ptvec[i].y(), ptvec[i].z())
# build connectivity array
k = 0
for j in range(nv - 1):
for i in range(nu - 1):
compConn[k, 0] = j * nu + i
compConn[k, 1] = j * nu + i + 1
compConn[k, 2] = (j + 1) * nu + i + 1
compConn[k, 3] = (j + 1) * nu + i
k += 1
# apply the offset to the connectivities
compConn += offset
# stack the results
pts = np.vstack((pts, compPts))
conn = np.vstack((conn, compConn))
# number of u and v point count
sizes[gind, :] = (nu, nv)
# cumilative number of points
cumSizes[gind + 1] = cumSizes[gind] + curSize
# increment the offset
offset += curSize
# increment geometry index
gind += 1
# finally, scale the points and save the data
self.pts0 = pts * self.modelScale
self.conn = conn
self.sizes = sizes
self.cumSizes = cumSizes
self.uv = uv
class PointSet:
"""Internal class for storing the projection details of each pointset"""
def __init__(self, points, pts, geom, r, s, t):
self.points = points
self.pts = pts
self.geom = geom
self.r = r
self.s = s
self.t = t
self.offset = self.pts - self.points
self.nPts = len(self.pts)
self.jac = None
```