Working with Fields
Last update: 18.06.2026Fields are the primary data containers in DPF. This guide covers creating, manipulating, and extracting data from fields.
What is a Field?
A Field contains:
- Data: Numerical values (scalars, vectors, matrices)
- Scoping: Entity IDs (nodes, elements, etc.)
- Support: Time/mesh context
Creating Fields
From results
import Ans.DataProcessing as dpf
# Load model
model = dpf.Model(data_sources)
# Get stress field
stress_field = model.Results.Stress.GetOutput(0, dpf.LocationEnum.Elemental)
# Get displacement field
disp_field = model.Results.Displacement.GetOutput(0, dpf.LocationEnum.Nodal)
Manual creation
# Create an empty field
field = dpf.Field()
field.Location = dpf.LocationEnum.Nodal
field.NumberOfComponents = 3 # Vector field
# Set scoping (node IDs)
scoping = dpf.Scoping()
scoping.SetIds([1, 2, 3, 4, 5])
field.Scoping = scoping
# Set data
data = [1.0, 0.0, 0.0, # Node 1: [1, 0, 0]
0.0, 1.0, 0.0, # Node 2: [0, 1, 0]
0.0, 0.0, 1.0, # Node 3: [0, 0, 1]
1.0, 1.0, 0.0, # Node 4: [1, 1, 0]
0.0, 1.0, 1.0] # Node 5: [0, 1, 1]
field.Data = data
Accessing Field data
Get all data
# Get all data as a list
data = field.Data
print(f"Total values: {len(data)}")
# Get number of entities
num_entities = field.ElementaryDataCount
print(f"Number of entities: {num_entities}")
Get data for specific entities
# Get data for first entity
entity_data = field.GetEntityDataByIndex(0)
print(f"Entity 0 data: {entity_data}")
# Get data for entity by ID
entity_id = 100
entity_data = field.GetEntityData(entity_id)
Iterate over field
# Iterate through all entities
for i in range(field.ElementaryDataCount):
entity_id = field.Scoping.GetId(i)
data = field.GetEntityDataByIndex(i)
print(f"Entity {entity_id}: {data}")
Field properties
Component count
# Get number of components
num_comp = field.NumberOfComponents
# 1 = scalar, 3 = vector, 6 = symmetric tensor, 9 = full tensor
Location
# Get field location
location = field.Location
# LocationEnum.Nodal, LocationEnum.Elemental, etc.
Scoping
# Get entity IDs
scoping = field.Scoping
ids = scoping.Ids
print(f"Field defined on {scoping.Count} entities")
Field operations with operators
Compute magnitude
# Create norm operator
norm_op = dpf.Operator("norm")
norm_op.SetInput(0, field)
magnitude_field = norm_op.GetOutput(0, dpf.Field)
Component extraction
# Extract X component (component 0)
comp_op = dpf.Operator("component_selector")
comp_op.SetInput(0, field)
comp_op.SetInput(1, 0) # Component index
x_component = comp_op.GetOutput(0, dpf.Field)
Field math
# Add two fields
add_op = dpf.Operator("add")
add_op.SetInput(0, field1)
add_op.SetInput(1, field2)
result = add_op.GetOutput(0, dpf.Field)
# Scale a field
scale_op = dpf.Operator("scale")
scale_op.SetInput(0, field)
scale_op.SetInput(1, 2.5) # Multiplication factor
scaled_field = scale_op.GetOutput(0, dpf.Field)
FieldsContainer
For multi-step results, use FieldsContainer:
# Get all time steps
fields_container = model.Results.Displacement.GetOutput(dpf.LocationEnum.Nodal)
# Access individual fields
num_fields = fields_container.Count
print(f"Number of fields: {num_fields}")
# Get field for specific time step
field_at_step_5 = fields_container.GetField(5)
# Iterate through all fields
for i in range(fields_container.Count):
field = fields_container.GetField(i)
time_id = fields_container.GetTimeFreqCumulativeIndex(i)
print(f"Field at time {time_id}")
Best practices
- Check field properties: Always verify component count and location
- Use operators: Prefer operators over manual data manipulation
- Scoping awareness: Understand which entities your field represents
- Memory management: Dispose large fields when done
- Batch processing: Use FieldsContainer for multi-step operations
