Visustin Large flow charts

Large charts are best viewed on the screen either in Visustin itself or as PDF. A large monitor gives you the best view into complex flow charts. Visustin has no built-in size limitation, but various technical reasons may limit what you can do with huge charts. Even when Visustin can produce very large charts, such as 5050 sheets or 5000050000 pixels, printing or saving may turn impractical. Saving as PDF usually works out best.

Good news to veteran users! Visustin is now significantly more robust than before. Versions prior to 6 were limited to some 100 kB or 3000 lines at a time. This limitation has been lifted.

Ways to handle large charts

Quick tip #1. Work large files in parts. Use the Structure tab to create partial flow charts of a file.

Quick tip #2. Press Birdseye instead of Draw.

Quick tip #3. Save as PDF.

Quick tip #4. Use options to create smaller charts: Shorten code (or Minimal code), Hide comments, Black & White, Font size 7pt, Zoom 100%.

Viewing large charts

Navigating in large charts is easier with the navigation features Visustin provides.

Keeping charts smaller

A smaller physical chart size means increased performance. You have several ways to keep the chart area down.

Memory considerations

A large flow chart can consume 500 MB RAM or more. If Visustin appears to work slowly because of the chart size, try the following tricks:

The Statistics command in the View menu tells you the chart size and the current memory requirements. You can also use the Windows Task Manager to determine the overall memory usage of Visustin.

Extremely large charts

The table below shows the results of a stress test with very large input files. The test was run with the default options: Flow chart, Zoom level 100%, 9pt Arial font, Color chart, Comments as detached labels.

Source kBSource linesLanguageMemoryPixelsSheets
161 kB5,000Fortran200 MB29,00010,000409
263 kB7,300VB6200 MB110,00012,00014010
557 kB12,000VB6650 MB112,00046,00014739
546 kB18,000T-SQL500 MB52,00056,0006548
1.2 MB31,000Visual FoxPro1600 MB340,00032,00035327

Memory = Peak Mem Usage after pressing Draw. Sheets = Print-out size on regular paper (A4 portrait).

While these charts display well, it is not practical to print or save them in their entirety.

Do not expect miracles from Windows or your printer. Printing the 6548 sheet chart failed with a Windows error message about a result exceeding the limits of a 32-bit integer. Saving as PDF worked fine.

On a separate note, it's good programming practice to keep source files at a reasonable size. Besides making flowcharting easier, smaller files are easier to understand and maintain as well.

Troubleshooting large charts

Chart does not show up
Press Birdseye instead of Draw.
Chart shows up but saving fails
1) The file format does not support large images. Save as PDF instead.
2) The complete bitmap is too large for Windows. Save in parts via the Structure tab.
3) You are running low on memory. Close other applications and try again.
Printing fails
Print in parts. Use the Structure tab to print parts of the code at a time.
Zooming displays rasterized picture or strange colors
You are running low on memory. Visustin has switched to low-color mode to preserve RAM. Close other programs to free some memory or add RAM into your system. You can also try zooming again as the operating system may have freed up some memory meanwhile. Visustin requires physical RAM, not just virtual memory.
Zooming stops working
The image is too large to zoom. Try zooming out to a lower level (below 50%).
Bulk charting fails
Check Split files by Structure to process the files in parts.

Increasing system performance

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