Use of "true shape" feature in arch shape and road
Document history:
- 2024-02-14. Updated to reflect greater file format and file extension flexibility from version 2.6.
The true shape feature allows use of survey data to define the intrados of the arch.
Data points can be manually entered or loaded from a file (which might be prepared and exported from Excel or similar).
Please look at the result. Does the shape match that shown in photographs? Note that even if the points are on the arch, the interpolation algorithm may not get the shape of the arch right. If it looks wrong, it probably is.
Interpolation isn't magic - it can't fill in information that isn't in the data.
If there is a kink in the shape, you will need 2 or mode points near it, or it will be smoothed over by the interpolation.
7 points is an absolute theoretical minimum and very rarely works. 2 points are needed close to each end.
If you are getting odd results, try putting your coordinates into Excel and see what that makes of the curve.
Loading a survey file
The Load from file... button will open the file dialog.
Survey data files must have the .sur extension (not .txt or .csv).
In Archie-M 2.6 and up, the file open dialog will allow you to filter for common data file extensions (csv, txt, ...) as well as .sur. The data files for true shape in 2.6 and up can use any delimiter (space, tab, comma, semicolon ...).
In Archie-M version 2.5.1, survey data files must have the .sur extension (not .txt, .csv, .tsv or anything else) to be visible in the file open dialog. The file contents must be space separated (not tab or comma):
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