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Sparse Matrix CSV Workbench

Convert a labeled dense CSV matrix into coordinate triplets, or rebuild a dense matrix from sparse row, column and value records.

Dense matrixEditable projectsLocal processing

Source → inspect → export

Open project

Preparing the worked example…

Your source & settings

Settings & options

Open your media file

Files stay in your browser. Try the built-in sample first.

Choose file

Source text is limited to 1.5 million characters per editor; imported text files are limited to 1.5 MB.

Inspect your result

PREVIEW & EXPORT

Output file

Know what changed

Dense input uses its first column as row labels. Sparse input needs row,column,value headers. Numeric finite values only; reconstructed grids are limited to 10,000 cells. Axis preservation inserts structural zero entries so entirely zero rows and columns can round-trip.

Choose another output above or open Export files.

Explore the example

Convert a labeled dense CSV matrix into coordinate triplets, or rebuild a dense matrix from sparse row, column and value records.

What you can inspect

Dense matrix — row, A, B, C.
Sparse coordinates — row, column, value.

Keep the result you need

Use the output selector to inspect each generated file, then download it. Save a project to keep source inputs and settings together. Result files and editable projects serve different purposes.

Processing & file support

Source text is limited to 1.5 million characters per editor; imported text files are limited to 1.5 MB.

Your working session

Processing runs locally in a worker with a 30-second cancellation limit. Undo and redo keep up to 20 edits in this tab. Project files include imported assets and are limited to 40 MiB. There is no automatic saving.

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Using Sparse Matrix CSV Workbench

Convert a labeled dense CSV matrix into coordinate triplets, or rebuild a dense matrix from sparse row, column and value records.

Start with the worked example in matrix csv, then paste your own source or open a text file.
Adjust input layout, repeated sparse coordinate. Change one setting at a time so you can understand its effect.
Choose “Process source”. Inspect the dense matrix and sparse coordinates before using the result.
Download the selected output, inspect other files in Export files and save a project if you want to reopen the same inputs.

Example

Try the built-in example, inspect dense matrix and compare the result after changing one option.

Questions & answers

What does Sparse Matrix CSV Workbench do?

Convert a labeled dense CSV matrix into coordinate triplets, or rebuild a dense matrix from sparse row, column and value records.

What are the important limitations?

Can I save and reopen my work?

Yes. Save a project JSON file containing your inputs, settings and any imported assets. Projects are limited to 40 MiB. Undo/redo stores up to 20 edits in this session and is not saved in the project. There is no automatic saving.

How do imports and output previews work?

Source text is limited to 1.5 million characters per editor; imported text files are limited to 1.5 MB. Text previews show up to 150,000 characters; downloads include the complete output. Tables show 50 rows per page; CSV files include all rows.