Tableau Magic to cast Date_Id to a convenient date format, assumed YYYYMMDD

Function for assigning a date to a bi-annual period: Useful when needing to group dates into a period for time-series visualisation

This visualization example demonstrates a utility function for converting individual dates into bi-annual period groupings, a preprocessing step for time-series analysis. The function uses `lubridate`'s `dmy`, `year`, and `floor_date` functions to compare each input date against two fixed cutpoints (June 30th and December 31st), then returns the first day of the month for the appropriate six-month period. Dates falling after the second cutpoint are assigned to the following year’s first period, ensuring all data maps to a two-category annual cycle. The code explicitly handles year boundaries through conditional `ifelse` logic.

JJustinCally

50% match

Gist 42c5413995001df2d448d010b837dc33

This example visualizes daily user activity by counting how many user records reference each date. It shows a timeline of update frequencies derived from a hardcoded JavaScript object mapping user IDs to date-keyed booleans. The code builds a string of user IDs and their associated dates, then uses `String.split(date)` on that concatenated string to count occurrences of each date in the `updates` object. It relies on the Moment.js library to generate the last ten dates via `moment().subtract()` and formats them as `DD-MM-YYYY`. The rendering itself is absent—the example focuses solely on data aggregation logic, with no charting or DOM output.

AA6Brgeuka

49% match

Counting Weekdays

This example demonstrates how to count the number of weekdays between any date and January 1, 1970, using the custom `weekday` function, which also provides an `invert` method to reverse the calculation. The code defines helper functions `weekdaysInYear` and `weekdayOfYear` to compute weekday totals per year and per date, accounting for skipped weekends. It relies on the D3.js library’s `d3.time` methods, such as `d3.time.dayOfYear` and `d3.time.year`, to extract day-of-year and year information from JavaScript `Date` objects, enabling accurate weekday arithmetic without external data.

Mmbostock

Gist adad8e220a1e17f2d97fbabd7315d685

This example shows how to create a Tableau data extract from a shared expression table, mapping source columns `Name` and `Value` into a two-column table within the `tab` database. The code uses the Tableau `.tmsl` metadata format, specifically the `create` and `partitions` APIs, to define the table structure and pull data from the `#sections[main][SharedExpression]` expression. The table is named `SharedExpressionTable` and is built with a full data view, demonstrating how to programmatically generate a Tableau data model from an embedded expression source.

TODAY() function in Power Query

This example demonstrates how to retrieve the current date from Power Query by leveraging the local Analysis Services instance that Power BI Desktop uses internally. The visualization shows the TODAY() function’s result fetched through a DAX query executed against a dynamic port number. The code uses the Folder.Contents and Folder.Files functions to locate the msmdsrv.port.txt file, which stores the active port, then passes that port to AnalysisServices.Database to run the query. The output is a table with a single row containing the current date, reflecting the system’s local date at query time.

DAX measure that formats a measure `[Quantity]` into a roman numeral

This example shows a Power BI table where the `[Quantity]` measure is transformed into a roman numeral representation, displayed alongside the original numeric values for brands like A. Datum and Adventure Works. The DAX measure uses `GENERATESERIES` and `FLOOR` to extract each digit’s position, then `LOOKUPVALUE` against a static `DATATABLE` that maps powers of ten (1, 10, 100, up to 300,000) to their corresponding roman numerals, including overline notation for values above 3,999. The `CONCATENATEX` function concatenates these digit-specific roman strings in descending order of place value, producing outputs like `V̅I̅DCCCXCVII` for 6,897. The approach relies entirely on DAX’s table functions and does not use any external JavaScript libraries or rendering APIs.

XQuery Puzzles from Week 1, Day 5, Session 4 of the Advanced Digital Editions NEH Institute at the University of Pittsburgh

This gallery example presents a set of XQuery 3.1 puzzle solutions designed to transform data formats. One function converts a textual date like "July 15, 2022" into an `xs:date` value by tokenizing the string and using a `switch` expression to map month names to numbers, while another script processes a sequence of dates with a `for` loop. A third function converts Roman numerals to integers, using `string-to-codepoints` and `codepoints-to-string` to iterate over characters and applying a conditional sum to handle subtractive notation. The code does not use any visualization libraries; the source is a gist by CliffordAnderson.

CCliffordAnderson

47% match

Gist ba3a80c35942582d77235e9fb4173416

This example shows a small, inline sparkline generated as a Scalable Vector Graphic (SVG) image URL from a Power BI measure. It plots a measure’s values over time for a single category, mapping each date to an X coordinate and each value to a Y coordinate within a 100×100 viewBox. The code uses DAX variables like `MINX`, `MAXX`, and `SUMMARIZE` to compute the normalized coordinates, then concatenates them into a `polyline` string. The result is rendered as a data URI with `data:image/svg+xml;utf8`, relying on the table’s `Date` and `Category` fields.