Convert PlotData of User Defined Result to a DPF field and plot it

Pernelle Marone-Hitz

In Mechanical scripting, how can I retrieve the data from a user-defined result and plot it as a Python Result ?

Pernelle Marone-Hitz

A user-defined result (UDR) is inserted in Mechanical :

A property is added to the Python Result for the user to provide the name of the UDR:

This is achieved by modifying the Property Provider of the Python Result:

The piece of code of interest here is:

def reload_props():
    this.PropertyProvider = None
 
    # Create the property instance
    provider = Provider()
    
    input_group = provider.AddGroup("Input")
    ns_prop = input_group.AddProperty("UDR Name", Control.Expression)
    
    # Connects the provider instance back to the object by setting the PropertyProvider member on this, 'this' being the 
    # current instance of the Python Code object.
    this.PropertyProvider = provider
 
 

Then, the Script part of the Python Result is edited:

The code that is needed here is :

def post_started(sender, analysis):# Do not edit this line
    define_dpf_workflow(analysis)
 
def define_dpf_workflow(analysis):
    
    # import DPF
    import mech_dpf
    import Ans.DataProcessing as dpf
    mech_dpf.setExtAPI(ExtAPI)
    
    # Connect to result file
    dataSource = dpf.DataSources(analysis.ResultFileName)
    
    # Retrieve mesh 
    model=dpf.Model(dataSource)
    mesh=model.Mesh # whole mesh
    
    # Retrieve property values
    udr_name = str(this.GetCustomPropertyByPath("Input/UDR Name").Value)
    
    # Access User Defined Result and create a field out of it
    udr = ExtAPI.DataModel.GetObjectsByName(udr_name)[0]
    nb_nodes = len(udr.PlotData['Node']) # get number of nodes 
    
    udr_field = dpf.FieldsFactory.CreateScalarField(nb_nodes) # instanciate field
    udr_field.MeshedRegionSupport = mesh # attach mesh
    udr_field.ScopingIds = udr.PlotData['Node'] # give list of nodes
    udr_field.Data = [0. for i in range(0,nb_nodes)]# fill field with zeros
    node_ids = udr.PlotData['Node']
    values = [value for value in udr.PlotData['Values']]
    for ii in range(0,nb_nodes):
        index=udr_field.ScopingIds.IndexOf(node_ids[ii])         # get index of node in created field
        udr_field.UpdateEntityDataByEntityIndex(index,[values[ii]])  
    
    # Create field operator for plotting
    forward = dpf.operators.utility.forward_field()
    forward.inputs.field.Connect(udr_field)
    
    dpf_workflow = dpf.Workflow()
    dpf_workflow.Add(forward)
    dpf_workflow.SetOutputContour(forward)
    dpf_workflow.Record('wf_id', False)
    this.WorkflowId = dpf_workflow.GetRecordedId()

This code grabs the UDR, extract the values in it thanks to PlotData, and passes those values to a DPF Field to be able to plot it in the Python Result object.

Ray_Greene

Pernelle:
Thanks so much for posting this!
I was able to do some (work) cool application by mouse click applying it but it failed with automation
Why? DPF Python Result is "def post_started(sender, analysis):", i.e. it runs before UDR data is populated by post. On the other hand, a Python Code object is "def after_post(this, solution)", i.e. it runs after UDR data is populated by post - what is needed to use UDR results in DPF with automation. Do you have any suggestions for how to do this? I tried putting time.sleep(time_sleep) in the DPF code but it did not work.
Cordially,
Ray

Pernelle Marone-Hitz

Hi @Ray_Greene , glad you found that post useful! Indeed I hadn't realized this would not work in an automated way. There is unfortunately no workaround possible, the only solution would be to execute the two objects manually and in a successive manner.
I also tried having a Python Code object in "after post" unsuppress the Python Result and evaluate, but Python Results do not have a Suppressed / Unsuppressed status so this is not a viable path either.
Looks like something that could be improved, I'll let the developers know.