Read and Write SG Data#

Every format goes through one in-memory object. sgio.read() loads a solver or mesh file into a sgio.StructureGene; sgio.write() emits one.

        flowchart LR
    subgraph IN ["Input"]
        direction TB
        VABS_I["VABS<br/>.sg"]
        SC_I["SwiftComp<br/>.sg"]
        ABQ_I["Abaqus<br/>.inp"]
        GMSH_I["Gmsh bundle<br/>.msh + .json"]
    end

    SG(["StructureGene"])

    subgraph OUT ["Output"]
        direction TB
        VABS_O["VABS<br/>.sg"]
        SC_O["SwiftComp<br/>.sg"]
        ABQ_O["Abaqus<br/>.inp"]
        GMSH_O["Gmsh<br/>.msh"]
        VTK_O["VTK / VTU<br/>.vtk .vtu"]
    end

    VABS_I -- "read" --> SG
    SC_I -- "read" --> SG
    ABQ_I -- "read" --> SG
    GMSH_I -- "read_sg_from_gmsh_bundle" --> SG

    SG -- "write" --> VABS_O
    SG -- "write" --> SC_O
    SG -- "write" --> ABQ_O
    SG -- "write" --> GMSH_O
    SG -- "write" --> VTK_O

VTK and VTU are write-only, mesh-only export targets. A bare .msh carries no material data, so Gmsh input is read as a bundle — see Prepare a Gmsh Mesh for SG Conversion.

sgio.convert() chains a read and a write in one call; see Convert SG Data.

Read#

import sgio

sg = sgio.read(
    'airfoil.sg',
    file_format='vabs',
    model_type='BM2',
    format_version='4.1',
)

file_format and model_type identifiers are listed in Formats and Model Types. sgdim may be omitted when the format implies it — VABS is always 2D — and is required for formats that do not, such as a 3D Abaqus solid:

sg = sgio.read('cube.inp', file_format='abaqus', model_type='SD1', sgdim=3)

Write#

import sgio

sgio.write(sg, 'cross_section.sg', file_format='vabs', format_version='4.1')

Node and element IDs are renumbered automatically when the target format requires it, with a warning.

Pass mesh_only=True to write geometry without materials or analysis configuration — useful for visualization targets:

sgio.write(sg, 'visualization.msh', file_format='gmsh', mesh_only=True)

Full signatures are in I/O Functions.

See Also#