Welcome to Nodedge documentation¶

Nodedge is a free and open-source software for graphical programming. Try it out and contribute to its development!

Features

Create your simulation easily thanks to a large variety of customizable built-in blocks.
Access your models anywhere anytime. Nodedge is free for any purpose.
Contribute to Nodedge development. The software is based on Python.

Documentation

Introduction¶

Welcome to the Nodedge User’s Manual. This manual contains information on how to use the Nodedge software and includes the documentation for all the modules of the package and examples illustrating their use.

Installation¶

The nodedge package can be installed using pip or the standard distutils/setuptools mechanisms.

To install using pip:

pip install nodedge

Alternatively, to use setuptools, first clone or download the source. To install in your default python interpreter, use:

git clone git@github.com:nodedge/nodedge.git
cd nodedge
python setup.py install --user

Getting started¶

To use nodedge simply import the package as follows:

>>> import nodedge

Library conventions¶

The nodedge library uses a set of standard conventions for the way that different types of standard information used by the library.

LTI system representation¶

Linear time invariant (LTI) systems are represented in nodedge in state space, transfer function, or frequency response data (FRD) form. Most functions in the toolbox will operate on any of these data types and functions for converting between compatible types is provided.

State space systems¶

\[\begin{split}\frac{dx}{dt} &= A x + B u \\ y &= C x + D u\end{split}\]

where u is the input, y is the output, and x is the state.

Transfer functions¶

\[G(s) = \frac{\text{num}(s)}{\text{den}(s)} = \frac{a_0 s^m + a_1 s^{m-1} + \cdots + a_m} {b_0 s^n + b_1 s^{n-1} + \cdots + b_n},\]

where n is generally greater than or equal to m (for a proper transfer function).

nodedge package¶

Subpackages¶

nodedge.blocks package¶

Subpackages¶

nodedge.blocks.autogen package¶

Subpackages¶

nodedge.blocks.autogen.operator package¶

Submodules¶

nodedge.blocks.autogen.operator.add_block¶

nodedge.blocks.autogen.operator.eq_block¶

nodedge.blocks.autogen.operator.ge_block¶

nodedge.blocks.autogen.operator.gt_block¶

nodedge.blocks.autogen.operator.le_block¶

nodedge.blocks.autogen.operator.lt_block¶

nodedge.blocks.autogen.operator.mod_block¶

nodedge.blocks.autogen.operator.mul_block¶

nodedge.blocks.autogen.operator.pow_block¶

nodedge.blocks.autogen.operator.sub_block¶

nodedge.blocks.autogen.operator.truediv_block¶

Module contents¶

nodedge.blocks.custom package¶

Submodules¶

nodedge.blocks.custom.input_block¶

nodedge.blocks.custom.output_block¶

Module contents¶

Submodules¶

nodedge.blocks.block¶

nodedge.blocks.block_config¶

nodedge.blocks.block_exception¶

Block exception module containing EvaluationError, MissInputError, and RedundantInputError classes.

exception nodedge.blocks.block_exception.EvaluationError¶

Bases: Exception

EvaluationError class

If a block cannot be evaluated, raise this error.

exception nodedge.blocks.block_exception.MissInputError¶

Bases: EvaluationError

MissInputError class

If an input is missing to a block, preventing it to be evaluated, raise this error.

exception nodedge.blocks.block_exception.RedundantInputError¶

Bases: EvaluationError

RedundantInputError class

If two different inputs are connected to a single input socket of a block, raise this error.

nodedge.blocks.graphics_block¶

nodedge.blocks.graphics_block_content¶

nodedge.blocks.graphics_input_block_content¶

nodedge.blocks.graphics_output_block_content¶

Module contents¶

Submodules¶

nodedge.application_styler¶

nodedge.connector¶

nodedge.edge¶

nodedge.edge_dragging¶

nodedge.edge_validators¶

nodedge.editor_window¶

nodedge.graphics_cut_line¶

nodedge.graphics_edge¶

nodedge.graphics_node¶

nodedge.graphics_node_content¶

nodedge.graphics_node_title_label¶

nodedge.graphics_scene¶

nodedge.graphics_socket¶

nodedge.graphics_view¶

nodedge.logger¶

Logger module containing function to set up logging functionalities.

nodedge.logger.setupLogging(defaultPath: str = '../logging.yaml', defaultLevel: int = 10, envKey: str = 'LOG_CFG')¶: Logging Setup

nodedge.logger.highLightLoggingSetup()¶

nodedge.mdi_area¶

nodedge.mdi_window¶

nodedge.node¶

nodedge.scene¶

nodedge.scene_clipboard¶

nodedge.scene_coder¶

nodedge.scene_history¶

nodedge.serializable¶

Serializable “interface” module. It is an abstract class.

class nodedge.serializable.Serializable¶

Bases: object

Serializable class

Create data which are common to any serializable object.

It stores the id of the object used in the SceneHistory, the SceneClipboard, and the file structure.

serialize() → OrderedDict¶

Serialization method to serialize this class data into OrderedDict which can be stored in memory or file easily.

Returns: data serialized in OrderedDict
Return type: OrderedDict

deserialize(data: dict, hashmap: Optional[dict] = None, restoreId: bool = True, *args, **kwargs) → bool¶

Deserialization method which take data in python dict format with helping hashmap containing references to existing entities.

Parameters

data (dict) – dictionary containing serialized data
hashmap (dict) – helper dictionary containing references (by id == key) to existing objects
restoreId (bool) – True if we are creating new sockets. False is useful when loading existing sockets which we want to keep the existing object’s id

Returns

True if deserialization was successful, False otherwise

Return type

bool

nodedge.socket_type¶

<ModuleName> module containing ~nodedge. class.

class nodedge.socket_type.MyClass¶

Bases: object

~nodedge. class .

class nodedge.socket_type.SocketType(value)¶

Bases: Enum

An enumeration.

Any = 0¶

Number = 1¶

String = 2¶

nodedge.utils¶

Module contents¶

Examples¶

The source code for the examples below are available in the examples/ subdirectory of the source code distribution. They can also be accessed online via the nodedge GitHub repository.

Python scripts¶

Evaluation¶

The evaluation system uses eval() and evalChildren(). eval is supposed to be overridden by your own implementation. The evaluation logic uses Flags for marking the Nodes as Dirty and/or Invalid.

Evaluation Functions¶

There are 2 main methods used for the evaluation:

eval()
evalChildren()

These functions are mutually exclusive. That means that evalChildren does not eval the current Node, but only children of the current Node.

By default the implementation of eval() is “empty” and return 0. However, if successful, eval resets the Node not to be Dirty nor Invalid. This method is supposed to be overridden by your own implementation. If you look for examples, please check out examples/example_calculator to get inspiration on how to setup your own Node evaluation.

The evaluation takes advantage of the Node flags described below.

`Node` Flags¶

Each Node has 2 flags:

Dirty
Invalid

The Invalid flag has always higher priority over Dirty. This means that if the Node is Invalid it does not matter whether it is Dirty or not.

To mark a node as Dirty or Invalid there are respective methods markDirty() and markInvalid(). Both methods take bool parameter for the new state. You can mark Node dirty by setting the parameter to True. Also you can un-mark the state by passing False value.

For both flags there are 3 methods available:

markInvalid() - to mark only the Node
markChildrenInvalid() - to mark only the direct (first level) children of the Node
markDescendantsInvalid() - to mark it self and all descendant children of the Node

The same applies to the Dirty flag:

markDirty() - to mark only the Node
markChildrenDirty() - to mark only the direct (first level) children of the Node
markDescendantsDirty() - to mark it self and all descendant children of the Node

Descendants or Children are always connected to the Output(s) of the current Node.

When a node is marked as Dirty or Invalid one of the two event methods, onMarkedInvalid() or onMarkedDirty(), is called. By default, these methods do nothing. However, they are implemented for you to override and use them in your own evaluation system.

Event system¶

Nodedge uses its own events (and tries to avoid using Signal) to handle logic happening inside the Scene. If a class does handle some events, they are usually described at the top of the page in this documentation.

Any of the events is subscribable to and the methods for registering callback are called:

add<EventName>Listener(callback)

You can register to any of these events any time.

Events used in Nodedge:¶

`Scene`¶

Has Been Modified
when something has changed in the Scene

Item Selected
when Node or Edge is selected

Items Deselected
when deselect everything appears

Drag Enter
when something is Dragged onto the Scene. Here we do allow or deny the drag

Drop
when we Drop something into the Scene

`SceneHistory`¶

History Modified
after History Stamp has been stored or restored

History Stored
after History Stamp has been stored

History Restored
after History Stamp has been restored

Serialization¶

All of serializable classes derive from Serializable class. Serializable does create commonly used parameters for our classes. In our case it is just id attribute.

Serializable defines two methods which should be overridden in child classes:

According to coding-standards we keep these two functions on the bottom of the class source code.

To contain all of the data we use OrderedDict instead of regular dict. Mainly because we want to retain the order of parameters serialized in files.

Classes which derive from Serializable:

Scene
Node
QDMNodeContentWidget
Edge
Socket

Index

Development

You can check out the latest version of the source code with the command:

git clone https://github.com/nodedge/nodedge.git

You can run a set of unit tests to make sure that everything is working correctly. After installation, run:

python setup.py test

Your contributions are welcome! Simply fork the GitHub repository and send a pull request.

Links

Issue tracker: https://github.com/nodedge/nodedge/issues

Welcome to Nodedge documentation¶

Introduction¶

Installation¶

Getting started¶

Library conventions¶

LTI system representation¶

State space systems¶

Transfer functions¶

nodedge package¶

Subpackages¶

nodedge.blocks package¶

Subpackages¶

nodedge.blocks.autogen package¶

nodedge.blocks.custom package¶

Submodules¶

nodedge.blocks.block¶

nodedge.blocks.block_config¶

nodedge.blocks.block_exception¶

nodedge.blocks.graphics_block¶

nodedge.blocks.graphics_block_content¶

nodedge.blocks.graphics_input_block_content¶

nodedge.blocks.graphics_output_block_content¶

Module contents¶

Submodules¶

nodedge.application_styler¶

nodedge.connector¶

nodedge.edge¶

nodedge.edge_dragging¶

nodedge.edge_validators¶

nodedge.editor_widget¶

nodedge.editor_window¶

nodedge.graphics_cut_line¶

nodedge.graphics_edge¶

nodedge.graphics_node¶

nodedge.graphics_node_content¶

nodedge.graphics_node_title_label¶

nodedge.graphics_scene¶

nodedge.graphics_socket¶

nodedge.graphics_view¶

nodedge.history_list_widget¶

nodedge.logger¶

nodedge.mdi_area¶

nodedge.mdi_widget¶

nodedge.mdi_window¶

nodedge.node¶

nodedge.node_tree_widget¶

nodedge.scene¶

nodedge.scene_clipboard¶

nodedge.scene_coder¶

nodedge.scene_history¶

nodedge.scene_item_detail_widget¶

nodedge.scene_items_table_widget¶

nodedge.serializable¶

nodedge.socket_type¶

nodedge.utils¶

Module contents¶

Examples¶

Python scripts¶

Evaluation¶

Evaluation Functions¶

Node Flags¶

Event system¶

Events used in Nodedge:¶

Scene¶

SceneHistory¶

Serialization¶

`Node` Flags¶

`Scene`¶

`SceneHistory`¶