# DVGeometryVSP

class pygeo.parameterization.DVGeoVSP.DVGeometryVSP(fileName, comm=mpi4py.MPI.COMM_WORLD, scale=1.0, comps=[], projTol=0.01)[source]

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:

1. Since VSP is volume-based, it cannot be used to parameterize a geometry that does not lie within a VSP body.

2. It cannot handle moving intersections. A geometry with static intersections is fine as long as the intersection doesn’t move

3. It does not support complex numbers for the complex-step method.

4. It does not support separate configurations.

5. Because OpenVSP does not provide sensitivities, this class uses parallel finite differencing to obtain the required Jacobian matrices.

Parameters
fileNamestr

filename of .vsp3 file.

commMPI Intra Comm

Comm on which to build operate the object. This is used to perform embarrassingly parallel finite differencing. Defaults to MPI.COMM_WORLD.

scalefloat

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.

compslist 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
>>>

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
pointsarray, size (N,3)

The coordinates to embed. These coordinates should all project into the interior of the FFD volume.

ptNamestr

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_globalfloat

The maximum distance betwen the points added and the projection on the VSP surfaces on any processor.

addVariable(component, group, parm, value=None, lower=None, upper=None, scale=1.0, scaledStep=True, dh=1e-06)[source]

Parameters
componentstr

Name of the VSP component

groupstr

Name of the VSP group

parmstr

Name of the VSP parameter

valuefloat 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

lowerfloat or None

Lower bound for the design variable. Use None for no lower bound

upperfloat or None

Upper bound for the design variable. Use None for no upper bound

scalefloat

Scale factor

scaledStepbool

Flag to use a scaled step sized based on the initial value of the variable. It will remain constant thereafter.

dhfloat

Step size. When scaledStep is True, the actual step is dh*value. Otherwise this actual step is used.

createDesignFile(fileName)[source]

Take the current set of design variables and create a .des file

Parameters
fileNamestr

name of the output .des file

getNDV()[source]

Return the number of DVs

Returns
len(self.DVs)int

number of design variables

printDesignVariables()[source]

Print a formatted list of design variables to the screen

setDesignVars(dvDict)[source]

Standard routine for setting design variables from a design variable dictionary.

Parameters
dvDictdict

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.

totalSensitivity(dIdpt, ptSetName, comm=None, config=None)[source]

This function computes sensitivity information.

Specifically, it computes the following: $$\frac{dX_{pt}}{dX_{DV}}^T \frac{dI}{d_{pt}}$$

Parameters
dIdptarray 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.

ptSetNamestr

The name of set of points we are dealing with

commMPI.IntraComm

The communicator to use to reduce the final derivative. If comm is None, no reduction takes place.

Returns
dIdxDictdict

The dictionary containing the derivatives, suitable for pyOptSparse

totalSensitivityProd(vec, ptSetName, comm=None, config=None)[source]

This function computes sensitivity information.

Specifically, it computes the following: $$\frac{dX_{pt}}{dX_{DV}} \ vec$$

This is useful for forward AD mode.

Parameters
vecdictionary whose keys are the design variable names, and whose

values are the derivative seeds of the corresponding design variable.

ptSetNamestr

The name of set of points we are dealing with

commMPI.IntraComm

inactive parameter, this has no effect on the final result because with this method, the reduction is performed externally

Returns
xsdotarray (Nx3) -> Array with derivative seeds of the surface nodes.
totalSensitivityTransProd(dIdpt, ptSetName, comm=None, config=None)[source]

This function computes sensitivity information.

Specifically, it computes the following: $$\frac{dX_{pt}}{dX_{DV}}^T \frac{dI}{d_{pt}}$$

Parameters
dIdptarray 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.

ptSetNamestr

The name of set of points we are dealing with

commMPI.IntraComm

The communicator to use to reduce the final derivative. If comm is None, no reduction takes place.

Returns
dIdxDictdic

The dictionary containing the derivatives, suitable for pyOptSparse

update(ptSetName, config=None)[source]

This is the main routine for returning coordinates that have been updated by design variables. Multiple configs are not supported.

Parameters
ptSetNamestr

Name of point-set to return. This must match ones of the given in an addPointSet() call.

configstr or list

Inactive parameter for DVGeometryVSP. See the same method in DVGeometry.py for its normal use.

writePlot3D(fileName, exportSet=0)[source]

Write the current design to Plot3D file

Parameters
fileNamestr

name of the output Plot3D file

exportSetint

optional argument to specify the export set in VSP

writeVSPFile(fileName, exportSet=0)[source]

Take the current design and write a new VSP file

Parameters
fileNamestr

Name of the output VSP file

exportSetint

optional input parameter to select an export set in VSP