Data Mapping with XSLT3 Math Functions

XSLT3 adds trigonometry and other advanced math functions, new formatting functions, functions to collect environment variables, and more, extending XSLT and XSLT2 XML transformation standards. Data analysts and other data professionals can apply XSLT3 functions to solve XML data mapping and integration challenges that require complex mathematical computations. Let’s look at some MapForce examples of data mapping with XSLT3 math functions using trigonometry and other complex math expressions.

MapForce offers internal processing engines customized for various data types and applications.

Selecting the processing engine for data mapping with XSLT3

When you choose the XSLT3 engine the functions shown below are added to the Function Library window and are available for data mapping:

XQuery functions for data mapping with XSLT3

For example, we can create a data mapping that generates sine, cosine, and tangent for input values stored in an XML file. The original list came as a CSV file we imported into XMLSpy, the world’s best-selling JSON and XML editor, for conversion to XML.

We start the mapping in MapForce by dropping in XML Schemas for the input and output files, then connecting the root elements. At this point it’s important to select the standard target-driven connection type. This lets us customize each subsequent connection.

Target-driven element connection for customized data mapping

Next, we connect the Row elements, drag in the trig functions from the library, and connect the xvalue element from the source to each function and output element. Here is the completed data mapping:

Creating sine, cosine, and tangent values for the input data

Clicking the Output button below the mapping pane processes the input file, generates the output, and opens the preview window.

Output XML file containing sine, cosine, and tangent values

The input values in this example count from zero to 15 by tenths and the output contains each corresponding sine, cosine, and tangent. We can save the file and open it in XMLSpy, to take advantage of XMLSpy Grid view, create a highly customized graph, and even export the graph to include in a report or presentation:

View of the output file in XMLSpy grid view with a generated chart

Data Mapping with XSLT3 to Build Complex Expressions

You can combine XSLT3 functions with other functions in the library to build complex expressions. Let’s say we want to apply a quadratic equation like y = 4x2 – 3 to a list of input values. We can create a mapping that combines the XSLT3 pow function for the exponent with the core library functions for multiplication and addition.

Constructing a quadratic expression for a data mapping with XSLT3

Note the sequence of functions in the mapping explicitly defines the processing order implied in the expression: exponent first, then multiplication, then subtraction. If the expression used parentheses to override the default processing order, we would change the sequence of functions in the mapping to set the desired processing order.

Perhaps we want to run a set of input values through several variations of the expression and compare the results. We can create a user function to describe the expression and we can modify the structure of the output file to record the exponent, multiplier, and modifier used to generate each output file.

Here is the desired structure for each output file generated by variations of the expression:

Desired data structure for the quadratic expression result file

The user function will accept x values from the input XML file, calculate the expression, and will also pass the function parameters to be recorded in the output.

The quadratic expression as a user function

Here is the complete mapping with the expression in a user function:

The data mapping using the user function for the quadratic expression

 And the generated output file:

A partial view of the data mapping with XSLT3 for the quadratic expression

A user function can be easily inserted into other mappings or shared among multiple MapForce users. We start building a user function by selecting the functions that define the expression, then click the main Function menu:

Building a user function from components in an existing mapping

Here is our final definition of the user function:

Definition of the user function for the quadratic expression in the data mapping with XSLT3

If your data mapping and integration project requires data mapping with XSLT3 fortrigonometry or other advanced XSLT3 functions, check out MapForce, the award-winning, graphical data mapping tool for any-to-any data conversion and integration. Download a MapForce free trial including Tutorials, Help, and many more examples!

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