How do i get the result values of selected nodes?

I’m trying to add local min/max functionality in Mechanical as two separate buttons. When the user is viewing a result object—such as Equivalent Stress—and has selected some nodes, clicking one of these buttons should place a probe on the node with the minimum or maximum value. I’m currently stuck on the step where I need to retrieve the result values of the selected nodes. How can I do this?

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James Derrick

Hi @Bigpavel What does your code look like so far? Have you tried anything you think might work already?

Bigpavel

ResultType = Ansys.ACT.Automation.Mechanical.Results.Result
# get selected nodeIds
Selection = ExtAPI.SelectionManager.CurrentSelection
NodeIds = Selection.Ids
# get result object like equivalent stress or deformation
ResultObject = Tree.FirstActiveObject

# runs multiple checks to ensure the selections are valid
# ...

MaxValueNodeId = NodeIds[0]
MaxValue = 0
for NodeId in NodeIds:

    # I am looking for such a method for all kinds of results that
    # gets the scalar value of a result on a node, just like probe label values.
    # Unfortunately I have not find anything useful yet
    Value = ResultObject.GetNodeValue(NodeId)

    if Value > MaxValue:
        MaxValue = Value
        MaxValueNodeId = NodeId

# place a probe label on MaxValueNodeId
with Transaction():
    probeLabel = Graphics.LabelManager.CreateProbeLabel(ResultObject)
    probeLabel.Scoping.Node = MaxValueNodeId

said

Hi @Bigpavel, maybe something along these lines might work for you:

# The currently selected nodes are the nodes of interest
nodes_of_int = ExtAPI.SelectionManager.CurrentSelection

# The currently selected object on the tree is the result of interest
result = Tree.ActiveObjects[0]

# Get the result table in (nodes, value) format
result_table = result.PlotData

# Assumed initial minimum and maximum for comparison
# Assume a very large value for min_value and a very small value for max_value
min_value = 1e15
min_value_node = 0
max_value = 1e-15
max_value_node = 0

# Loop over all the entries in the results table
for i in range(len(result_table['Node'])):
    if result_table['Node'][i] in nodes_of_int:     # This is one of the selected nodes
        if result_table['Values'][i] < min_value:
            min_value = result_table['Values'][i]
            min_value_node = result_table['Node'][i]
        if result_table['Values'][i] > max_value:
            max_value = result_table['Values'][i]
            max_value_node = result_table['Node'][i]

print "Min value: ",min_value
print "Min value at node: ",min_value_node
print "Max value: ",max_value
print "Max value at node: ",max_value_node

Bigpavel

Hi @said! Thank you for your answer! I had to modify it a bit, because it is quite inefficient when you have 500k+ nodes in PlotData. Using a dictionary is much better, but it can still be slow with a high node count. Can you or someone else suggest me a more efficient method?

ResultTable = Result.PlotData

Hashmap = {}
for i in range(len(ResultTable['Node'])):
    Hashmap[ResultTable['Node'][i]] = ResultTable['Values'][i]

MaxValue = 1e-15
MaxValueNode = 0

for Node in NodesOfInt:
    NodeValue = Hashmap[Node]
    if NodeValue > MaxValue:
        MaxValue = NodeValue
        MaxValueNode = Node

said

Hi @Bigpavel there's a way to read results directly from the .rst file: https://ansyshelp.ansys.com/public/account/secured?returnurl=/Views/Secured/corp/v252/en/act_cust_mech/Postprocess_externalResultRetrieval.html#Mech_Results_Read_Results_RST_File

Ansys Help > Customization Suite > ACT Customization for Mechanical > Mechanical Feature Creation > Postprocessing Capabilities in Mechanical > Retrieving Mechanical Results More Efficiently > Retrieving Nodal Results

If I get some time, I will try to incorporate this method and share the script. But I hope this is a helpful starting point.

said

Hi @Bigpavel, maybe you can try this code:

import time
StartTime = time.time()

# The currently selected nodes are the nodes of interest
nodes_of_int = ExtAPI.SelectionManager.CurrentSelection

# The currently selected object on the tree is the result of interest
result = Tree.ActiveObjects[0]

# Get the result table in (nodes, value) format
# result_table = result.PlotData

reader = ExtAPI.DataModel.AnalysisList[0].GetResultsData()
rstdisp = reader.GetResult('U')

disp = rstdisp.GetNodeValues(nodes_of_int)
x_disp = list(disp[0::3])
y_disp = list(disp[1::3])
z_disp = list(disp[2::3])

tot_disp = []
for i in range(0,len(disp),3):
    res = sqrt(disp[i]**2 + disp[i+1]**2 + disp[i+2]**2)
    tot_disp.append(res)

max_tot_disp_idx = tot_disp.index(max(tot_disp))
max_tot_disp_node = nodes_of_int.Ids[max_tot_disp_idx]
min_tot_disp_idx = tot_disp.index(min(tot_disp))
min_tot_disp_node = nodes_of_int.Ids[min_tot_disp_idx]


print "Min value: ",min(tot_disp)
print "Min value at node: ",min_tot_disp_node
print "Max value: ",max(tot_disp)
print "Max value at node: ",max_tot_disp_node

print "Time taken for the script:",str(time.time()-StartTime)

For my small model, it didn't seem to improve the time much. But maybe you will see some reduction in time required for your bigger model.

Bigpavel

Thank you for your help @said!