Run Calcpad worksheets in your browser, offline

Open a .cpd worksheet

Open the app and use File, then Open, drag a .cpd file onto the page, or paste the text into a new Calcpad tab. The page calculates it straight away. A worksheet like this one is ordinary Calcpad:

'Right triangle
a = 3m
b = 4m
c = sqrt(a^2 + b^2)

It gives 5 m for the hypotenuse, with the units carried through. Everything the language offers is meant to work: units, vectors and matrices, $Plot and $Map plots, macros, #if and #while blocks, includes, input fields and the large function library.

Offline, and on your own computer

The first visit loads the app; after that a service worker keeps a copy, so the page opens and calculates with no network at all. You can install it from the browser as an app on a desktop or a phone. Worksheets are kept in the browser's own library or saved to your disk as ordinary .cpd text files, and nothing you calculate is sent anywhere. That makes it a practical way to read and check a colleague's worksheet on a machine where you cannot install software.

What was rebuilt, and what was kept

• The engine is a Rust port of the CalcpadCE calculation engine, compiled to WebAssembly. The page answers the calls the original made to its server itself, so no server is needed.
• The editor and report view are CalcpadCE's web frontend, with changes.
• Word and Excel export are built in the page. Equations become Word equations. The Excel workbook has the workings, variables and native charts.
• Installable and offline. A service worker caches the build so the page opens and calculates without a connection.

How close to CalcpadCE is it?

The Rust engine is tested against CalcpadCE's own test classes, transcribed to Rust, and against the expected-output files of its worksheets. Where it deliberately behaves differently, the difference is listed one by one with the test that pins it, in a file of deviations in the repository. One example: when an #if condition cannot be evaluated, the block is left unresolved with an error message, instead of silently running the #else branch.

Not supported: raster plots from the original's graphics library, the project and library path roots, and compiled .cpdz worksheets. The project is early, so if you depend on an unusual corner of the language, run your worksheet and compare the output before you switch.

Beyond the worksheet: sheets, imports and exports

On top of the Calcpad language there is a lighter way to write, called the sheet format: Markdown prose, name: expression -> unit | note lines and LaTeX. A sheet compiles to Calcpad and runs on the same engine, and you can always see the Calcpad it becomes with Show compiled. A ? in front of a value makes it an input, so a sheet becomes a fill-in template; the beam calculator is a worked one.

The same page can import worksheets from another calculation tool and export any worksheet to Word with real equations, to Excel with native charts, or to PDF.

Credit and licence

Calcpad was created by Nedelcho Ganchovski (Proektsoft); CalcpadCE is its MIT licensed continuation, at github.com/imartincei/CalcpadCE. CivilKit Calcs is MIT licensed too, and the upstream copyright notices are kept in the repository. If Calcpad is useful to you, look at the original project as well.