Example script

In the pydagoras github repository folder tests includes the script eg_use_pydagoras.py

The following simple DAG

image
will be created, updated and displayed by the following code

Import the necessary code from pydagoras
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from pydagoras.dag_dot import DAG_dot, calc
Define the node calculations
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    @calc
    def tripple(node=None):
        return node.get_value() * 3
Create the DAG
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    dag = DAG_dot(label='Eg DAG')
Define the input node and single calculation node
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    n2 = dag.makeNode('x3', calc=tripple, tooltip='multiply')
    n1 = dag.makeNode('In', calc=None, usedby=[n2], nodetype='in')
Print the initial DAG
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    print(dag.G.to_string())
Update the DAG input
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    dag.set_input('In', 10)
Print the final DAG
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    print(dag.G.to_string())

Putting it all together...

eg_use_pydagoras.py
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# eg_use_pydagoras.py
# a script to provide an example of creating and using a DAG using pydagoras

from pydagoras.dag_dot import DAG_dot, calc

def run():

    print('#######################################')

    @calc
    def tripple(node=None):
        return node.get_value() * 3

    dag = DAG_dot(label='Eg DAG')
    n2 = dag.makeNode('x3', calc=tripple, tooltip='multiply')
    n1 = dag.makeNode('In', calc=None, usedby=[n2], nodetype='in')

    print('Initial DAG')
    print(dag.G.to_string()) # (1)

    print('Updates --------------')
    dag.set_input('In', 10)

    print('Outputs --------------')
    dag.ppInputs() # (2)
    dag.ppOutput() # (3)
    dag.pp() 

    print('Final DAG')
    print(dag.G.to_string()) # (4)

if __name__ == '__main__':
    run()
    print('Done.')
  1. image 
    strict digraph  {
    graph [label="Eg DAG",
        labelloc=t,
        rankdir=LR
    ];
    out  [color=white];
    x3   [tooltip=multiply];
    x3 -> out    [fontname=Courier,
        label=Undefined];
    In   [shape=square];
    In -> x3     [fontname=Courier,
        label=Undefined];
}
  2. DAG: Eg DAG
Inputs:
NODE: in, id:In, value:10
      display_name:In tooltip:
      calc: None usedby:x3
  3.  NODE: out, id:out, value:30
      display_name:out tooltip: 
      calc: .calc_out at 0x1007b9b20> usedby:None
  4. image 
    strict digraph  {
    graph [label="Eg DAG",
        labelloc=t,
        rankdir=LR
    ];
    out  [color=white];
    x3   [color=green,
        fontcolor=blue,
        tooltip=multiply];
    x3 -> out    [color=green,
        fontcolor=blue,
        fontname=Courier,
        label=30];
    In   [color=green,
        fontcolor=blue,
        shape=square];
    In -> x3     [color=green,
        fontcolor=blue,
        fontname=Courier,
        label=10];
}