This node evaluates a (free-form) mathematical expression based on the values of the flow variables. The computed results can be either appended as new variable or be used to replace an input variable. Commonly used functions are shown in the list "Mathematical Functions". There are also some constants available, such as pi (the ratio of the circumference of a circle to its diameter) and e (the base of the natural logarithms).
This node uses JEP, the Java Math Expression Parser.
You can reference the integer flow variables like this: $${IflowVar}$$,
the floating point flow variables like this: $${DflowVar}$$.
NaN values act as value true in boolean expressions and compared to anything (including NaN) in any way (including ==, but not !=, which is like !(... == ...)) is false (0).
Please note the expressions are case sensitive.
Options
Popular Successors
- Row Filter10 %
- String Manipulation (Variable)8 %
- Math Formula (Variable)5 %
- Merge Variables5 %
- Math Formula4 %
- Rule-based Row Filter2 %
- Rule Engine2 %
- String Manipulation2 %
- CASE Switch Start2 %
- Date&Time Shift2 %
- Rule Engine Variable2 %
- Row Splitter1 %
- Constant Value Column1 %
- Counting Loop Start1 %
- Column Expressions< 1 %
- Variable Condition Loop End< 1 %
- Variable Loop End< 1 %
- Lag Column< 1 %
- DB Query Reader< 1 %
- Date&Time-based Row Filter< 1 %
- Column Filter< 1 %
- Joiner< 1 %
- k-Means< 1 %
CASE Switch Variable (Start)< 1 %- Counter Generation< 1 %
- Text Output Widget (legacy)< 1 %
- Variable to Table Row< 1 %
- Loop End< 1 %
- Recursive Loop End< 1 %
- Excel Writer< 1 %
IF Switch (Flow Variable Value)< 1 %- Column to Grid< 1 %
- IF Switch< 1 %
- Empty Table Creator< 1 %
- Create Date&Time Range< 1 %
- String Replacer< 1 %
- Variable Expressions< 1 %
Excel Writer (XLS)< 1 %- GroupBy< 1 %
- Partitioning< 1 %
Column Rename< 1 %File Reader< 1 %Recursive Loop Start< 1 %- Sorter< 1 %
Variable to Table Row< 1 %- CASE Switch End< 1 %
- Chunk Loop Start< 1 %
Recursive Loop End< 1 %- Row Sampling< 1 %
CASE Switch Data (Start)< 1 %Python Script (1⇒1)< 1 %- Recursive Loop Start< 1 %
- Generic Loop Start< 1 %
- Tree Ensemble Learner< 1 %
- Create File Name (legacy)< 1 %
- Table Creator< 1 %
- Rule-based Row Splitter< 1 %
- Send Email< 1 %
- Random Forest Learner< 1 %
Loop End< 1 %- Add Empty Rows< 1 %
- R Snippet< 1 %
- Integer Input (legacy)< 1 %
- Data Generator< 1 %
- Excel Reader< 1 %
- Create File/Folder Variables< 1 %
- Python Script (legacy)< 1 %
- Java Snippet< 1 %
- Java Edit Variable (simple)< 1 %
- Decision Tree Learner< 1 %
- Keras Input Layer< 1 %
- Interval Loop Start< 1 %
- Configurable End IF/CASE< 1 %
- Breakpoint< 1 %
Table Row to Variable< 1 %CASE Switch Variable (End)< 1 %- Random Number Assigner< 1 %
- Math Formula (Multi Column)< 1 %
- Parameter Optimization Loop End< 1 %
Variable to Table Column< 1 %Joiner< 1 %- Single Selection Configuration< 1 %
- Write To Excel Template (deprecated)< 1 %
- Table Row to Variable< 1 %
- Variable Creator< 1 %
- Duplicate Row Filter< 1 %
- Table Manipulator< 1 %
Table Writer< 1 %- Feature Selection Loop End< 1 %
Counting Loop Start< 1 %- Java Snippet (simple)< 1 %
- Date/Time Shift (legacy)< 1 %
Recursive Loop Start (2 ports)< 1 %- Cache< 1 %
- Moving Average< 1 %
- CSV Reader< 1 %
- Cross Joiner< 1 %
- Row Filter (Labs)< 1 %
- String Configuration< 1 %
- Ungroup< 1 %
- Fuzzy c-Means< 1 %
- Inject Variables (Data)< 1 %
Database Reader< 1 %- Java Edit Variable< 1 %
- Feature Selection Filter< 1 %
- Column List Loop Start< 1 %
- X-Partitioner< 1 %
- Auto-Binner< 1 %
- Column Rename (Regex)< 1 %
- Parameter Optimization Loop Start< 1 %
- Concatenate< 1 %
- Normalizer< 1 %
- Parallel Chunk Start< 1 %
- Python Source (legacy)< 1 %
- RDKit Diversity Picker< 1 %
- Rank< 1 %
- Top k Row Filter< 1 %
- Interactive Range Slider Filter Widget< 1 %
- RDKit Interactive Table< 1 %
- Missing Value< 1 %
- External Tool< 1 %
Flow Variable End IF< 1 %Flow Variable IF Switch (Flow Variable Value)< 1 %- Wait...< 1 %
Database Row Filter< 1 %Variable Condition Loop End< 1 %- Group Loop Start< 1 %
- Create Table Structure< 1 %
- Numeric Row Splitter< 1 %
- Column Splitter< 1 %
- Image Cropper< 1 %
- Moving Aggregator< 1 %
- Loop End (Column Append)< 1 %
- Polynomial Regression Learner< 1 %
- Cell Splitter< 1 %
- String to Number< 1 %
- Pivot< 1 %
- RowID< 1 %
- DB SQL Executor< 1 %
- DB Query< 1 %
- String Widget< 1 %
- String to Date&Time< 1 %
- Variable to Table Column< 1 %
- CSV Writer< 1 %
- Table Row to Variable Loop Start< 1 %
- SVM Learner< 1 %
- Number to String< 1 %
CASE Switch Model (Start)< 1 %- String to Path (Variable)< 1 %
- Double Configuration< 1 %
- Spark Row Filter< 1 %
- Line Plot< 1 %
- Configurable IF/CASE Switch (Flow Variable Value)< 1 %
- Configurable IF/CASE Switch< 1 %
- H2O AutoML Learner (Regression)< 1 %
Generic Loop Start< 1 %Recursive Loop End (2 ports)< 1 %Merge Variables< 1 %- Text Output (legacy)< 1 %
- R to Table< 1 %
IF Switch (Flow Variable Value)< 1 %Flow Variable IF Switch (Flow Variable Value)< 1 %- Random Numbers Generator< 1 %
- Kolmogorov-Smirnov Test< 1 %
- Keras Dense Layer< 1 %
Excel Reader (XLS)< 1 %- Topic Extractor (Parallel LDA)< 1 %
- File Reader< 1 %
- Column Combiner< 1 %
- Google Sheets Writer< 1 %
- Date&Time Configuration< 1 %
- Single Selection Widget< 1 %
Flow Variable IF Switch< 1 %- Catch Errors (Var Ports)< 1 %
Interval Loop Start< 1 %- Logistic Regression Learner< 1 %
Read Excel Sheet Names (XLS)< 1 %- Time Generator (legacy)< 1 %
- HTTP Retriever< 1 %
- DBSCAN< 1 %
- PCA< 1 %
- Column Merger< 1 %
- Domain Calculator< 1 %
Excel Reader (XLS)< 1 %Excel Sheet Appender (XLS)< 1 %- StanfordNLP NE Learner< 1 %
- Double Input (legacy)< 1 %
- Catch Errors (Data Ports)< 1 %
- Feature Selection Loop Start (1:1)< 1 %
- DB Reader< 1 %
- Integer Widget< 1 %
- Extract Date&Time Fields< 1 %
Table Row To Variable Loop Start< 1 %Variable to Table Row< 1 %CSV Reader< 1 %Database Table Selector< 1 %Database Connector< 1 %Gradient Boosted Trees Learner< 1 %- Create Temp Dir (legacy)< 1 %
- Bar Chart (JavaScript)< 1 %
- Distance Matrix to Network< 1 %
- String to Date/Time (legacy)< 1 %
Read MDB< 1 %- Run Garbage Collector< 1 %
- Missing Value Column Filter< 1 %
- Value Counter< 1 %
- Empty Table Switch< 1 %
- Interactive Table (legacy)< 1 %
- DB Row Filter< 1 %
- Java Distance< 1 %
- Similarity Search< 1 %
- H2O Predictor (Classification)< 1 %
Excel Reader (XLS)< 1 %Container Input (Variable)< 1 %- Data to Report (BIRT)< 1 %
- Window Loop Start< 1 %
XGBoost Tree Ensemble Learner< 1 %- RDKit Molecule Fragmenter< 1 %
Send Keys< 1 %- Table Reader< 1 %
- RProp MLP Learner< 1 %
- Nominal Value Row Filter< 1 %
- Nominal Value Row Splitter< 1 %
- Microsoft SQL Server Connector< 1 %
- t-SNE (L. Jonsson)< 1 %
- Virtual Screening Metrics< 1 %
Element Selector< 1 %- Unzip Files (legacy)< 1 %
- Try (Data Ports)< 1 %
- Try (Variable Ports)< 1 %
Variable to Table Column< 1 %Database SQL Executor< 1 %Variable Loop End< 1 %- Hierarchical Cluster Assigner (local)< 1 %
Cell Replacer< 1 %- Spark SQL Query< 1 %
Microsoft SQL Server Connector< 1 %- Gaussian Distributed Assigner< 1 %
- TimeDelay Loop Start< 1 %
- Line Chart (JFreeChart)< 1 %
- Java IF (Table)< 1 %
- Dictionary Replacer< 1 %
- Google Analytics Query (legacy)< 1 %
- Slider Input (legacy)< 1 %
- Generic JavaScript View (JavaScript)< 1 %
- Rotation 2D< 1 %
- Tile Loop Start< 1 %
- R to R< 1 %
- Table to R< 1 %
- GET Request< 1 %
- Extract Time Window (legacy)< 1 %
- Frequency Domain Features (FDF)< 1 %
- Diversity Picker< 1 %
- Fingerprint Similarity Calculator< 1 %
- Fingerprint NOT (Invert / Complement)< 1 %
- Shapefile Polygon Reader< 1 %
- Inject Variables (Database)< 1 %
Table Column to Variable< 1 %Table Row to Variable< 1 %CSV Writer< 1 %Database Connection Table Reader< 1 %Database Sampling< 1 %- X-Aggregator< 1 %
- Decision Tree Predictor< 1 %
K Nearest Neighbor< 1 %- K Nearest Neighbor< 1 %
- MultiLayerPerceptron Predictor< 1 %
- Logistic Regression Predictor< 1 %
Scorer< 1 %- Numeric Scorer< 1 %
- SMOTE< 1 %
- Association Rule Learner< 1 %
- Gradient Boosted Trees Learner< 1 %
Tree Ensemble Learner< 1 %- Tree Ensemble Predictor< 1 %
- Random Forest Learner (Regression)< 1 %
- Simple Regression Tree Learner< 1 %
- Numeric Binner< 1 %
Cell Splitter< 1 %Column Appender< 1 %- Column Resorter< 1 %
- Regex Split< 1 %
- Numeric Outliers< 1 %
- Single sample t-test< 1 %
- Statistics< 1 %
CASE Switch Data (End)< 1 %- End IF< 1 %
- Scatter Plot (legacy)< 1 %
- Color Manager< 1 %
Amazon Redshift Connector< 1 %- DB GroupBy< 1 %
DB Table Creator< 1 %- One Row to Many< 1 %
- Stresser< 1 %
- k-Medoids< 1 %
- Keras Network Learner< 1 %
- Dense Layer (legacy)< 1 %
- H2O Cross Validation Loop Start< 1 %
- H2O Binomial Scorer< 1 %
- Association Rule Learner (Borgelt)< 1 %
Excel Sheet Appender (XLS)< 1 %Excel Writer (XLS)< 1 %- NGram Creator< 1 %
- Term to String< 1 %
- File Upload (legacy)< 1 %
- String Input (legacy)< 1 %
- Line Plot (JavaScript)< 1 %
- ROC Curve (JavaScript)< 1 %
- Gaussian Convolution< 1 %
- Labeling Resizer< 1 %
- Image Resizer< 1 %
Python Source< 1 %Python Script (2⇒1)< 1 %Python Script (2⇒2)< 1 %- Python Edit Variable (legacy)< 1 %
- Python View (legacy)< 1 %
Double Input (legacy)< 1 %- R View (Table)< 1 %
- Date&Time Difference< 1 %
- Date&Time to String< 1 %
- RDKit MCS< 1 %
- RDKit Fingerprint< 1 %
- Information Gain Calculator< 1 %
- N-Gram Extractor< 1 %
- Get Pooled WebDriver< 1 %
- Start WebDriver< 1 %
- XLS Sheet Selector< 1 %
- Write Variables< 1 %
- URL Encode< 1 %
- Range Filter< 1 %
- ARIMA Predictor< 1 %
- Split Collection Column< 1 %
- Hierarchical Clustering< 1 %
- Scorer< 1 %
- Gradient Boosted Trees Learner (Regression)< 1 %
- Category to Number< 1 %
- Column Appender< 1 %
- Table Transposer< 1 %
- Extract Table Dimension< 1 %
- Box Plot (legacy)< 1 %
- Save Workflow< 1 %
- Create Spark Context (Livy)< 1 %
- DB Connector< 1 %
- Keras Embedding Layer< 1 %
- H2O Partitioning< 1 %
- Brat Document Writer< 1 %
- Punctuation Erasure< 1 %
- Stop Word Filter< 1 %
- Decompress Files< 1 %
- List Files/Folders< 1 %
- CSS Editor< 1 %
- Date&Time Widget< 1 %
- Container Input (Variable)< 1 %
- Container Input (JSON)< 1 %
- Webpage Retriever< 1 %
Views
- This node has no views
Workflows
(3D) Fragment library design workflowKNIME Hub- 00 Data GenerationKNIME Hub
- 00 Main MenuKNIME Hub
- 00 Main MenuKNIME Hub
- 00_Guided_Labeling_for_Document_Classification_(legacy)KNIME Hub
- Show all 1075 workflows
Links
- KNIME E-Learning Course: Creation and usage of Flow Variables in a KNIME workflowwww.knime.com/knime-introductory-course/chapter7/section1/creation-and-usage-of-flow-variables
- Rule Engine sum up to variablesby armingrudd on 2019-07-30forum.knime.com/p/66827
Developers
You want to see the source code for this node? Click the following button and we’ll use our super-powers to find it for you.