An Introduction to KNIME Analytics Platform
Dr. Lochana C. Menikarachchi
What is KNIME?
- KNIME is an open-source data analytics tool
- Written in Java with a visual interface
- Offers both open-source and commercial products
- Suitable for beginners and advanced users
Gartner Magic Quadrant Leader 2014-2018
KNIME Ecosystem
KNIME Wokspaces
- KNIME wokspaces are folders where preferences and workflows are saved
- If a workspace folder does not exist, it will be automatically created when selected
- Can be local folders or spaces in a remote location like KNIME hub
- Workspaces can be switched through KNIME workbench
- Different workspaces can be used for different projects to keep them clean and tidy
KNIME Hubs
- A collaborative platform that enables users to share, deploy, and manage analytical solutions
- Avaiable as a free community hub and customer managed commercial hubs
- Community hub is ideal for open collaboration among a wide audience of users
- Commercial hubs provide a more controlled and customizable environment tailored to organizational needs
Community Hub vs Commercial Hubs
| Feature | Community Hub | Commercial Hubs |
|---|---|---|
| License | Open-source, free | Paid licenses |
| Access | Public | Customer-managed |
| Collaboration | Robust collaboration features | Real-time collaboration, version control |
| Workflows Sharing | Public sharing | Public and private sharing |
| Secure Access | Private spaces | User authentication, roles-based permissions |
| Workflow Automation | Supports automation | Advanced scheduling, external integration |
| Customization | Open-source; some customization | Limited customization; paid add-ons |
| Community Engagement | Engage on forum | Forums, support channels |
KNIME Spaces
- KNIME spaces are virtual folders within KNIME hubs
- Spaces can be private or public areas
- Private spaces are accessible to the owner or anyone who obtained the permission from the space owner (this requires a paid team plan)
- Public spaces allow anyone with access to view and use content
- Spaces enhance project management and team collaboration
KNIME Spaces
- KNIME hub spaces are accessible from the KNIME workbench
- By default, one public space and one private space are available
- The KNIME workbench allows the creation of new spaces
- All newly created spaces are private by default
- The KNIME workbench does not allow the deletion of workspaces or changing their visibility to public
KNIME Spaces
- Change of workspace visibility and deletion can be done using a browser login (https://hub.knime.com/
user_name)
KNIME Workflows
- A workflow is an analysis flow consisting of a sequence of nodes that represent data analysis steps
- Nodes are the single processing units in a workflow, implementing and executing specific analysis steps graphically
KNIME Workflows
- Workflows can include operations like reading data, cleaning data, filtering data, and writing processed data into files
- KNIME workflows are represented as graphs (direct acyclic graphs) connecting nodes
- Some basic workflows can be found under Example Workflows directory
KNIME Nodes
- Nodes represent individual tasks in an analysis
- Each node is displayed as a colored box with input and output ports
KNIME Nodes
- The input is the data that a node receives via the input port
- The output is the resulting data sent from the output port
- Each node has specific settings that can be adjusted in a configuration dialog
Connecting Nodes
- Only ports of the same type indicated by the same color can be connected
Node Traffic Lights
- Each node’s state is indicated by a traffic light
Node States
| Node State | Traffic Light Color |
|---|---|
| Inactive and not yet configured | Red |
| Configured but not yet executed | Yellow |
| Executed successfully | Green |
| Error | Red cross |
| Warning | Yellow triangle with an exclamation mark |
KNIME Files
- KNIME workflows can be packaged and exported in .knwf or .knar files
- A .knwf file contains only one workflow
- A .knar file contains a group of workflows
KNIME Entry Page
KNIME UI (Modern)
KNIME UI (Classic)
- User interface can be switched by clicking Menu → Switch to classic user interface
KNIME Extensions
- Extensions are open source components that add additional functionalities
- Enable access to and processing of complex data types
- Include advanced algorithms and custom capabilities
- Enhance the functionality of the KNIME Analytics Platform
Installing Extensions
Workflow Annotations
- Annotations can be added by right-clicking the workflow editor
- Serve as documentation for complex workflows
- Enable better understanding
Meta Nodes and Components
- Metanodes and components aim to organize messy workflows
- Improve readability by isolating logical operations
- Reduce number of visible nodes for neater appearance
- Encapsulate blocks of operations within metanodes/components
Meta Nodes
- In a metanode, all flow variables come in from the parent workflow and all flow variables created within the component go out into the workflow
- Metanodes cannot have configuration windows
- Metanodes cannot have views
Components
- Flow variables created inside components stay within unless set in Component Output node
- External workflow flow variables cannot enter component without explicit setting in Component Input node
- Components can have configuration windows
- Components can have views
Metanodes vs. Components
| Feature | Meta Node | Component |
|---|---|---|
| Configuration settings | X | ✓ |
| Chart and plot view | X | ✓ |
| Isolate flow variables | X | ✓ |
| Clean up messy workflows | ✓ | ✓ |
Metanode or Component?
- Node with configuration settings? → a component
- Node producing a composite view? → a component
- To get rid of a flow variable? → a component
- To clean up a workflow? → a metanode
KNIME - R Integration
- Install base R and the R library RServe
- Search and Install extensions KNIME R Scripting and KNIME R Integration
- Set the R path in KNIME preferences
- Create and execute R scripts in KNIME
Setting R Path in KNIME
