Overriding Default Units with Special Formats

The #Units directive can be used to change the default units for both the length and angular quantities present in your data files -- that is, whether a distance measurement entered simply as  "10", for example,  will be interpreted as 10 feet instead of 10 meters.  It is possible, however, to override the defaults with specially formatted values.  Perhaps the easiest way to document this is by way of example:

Lengths (distances, heights, tape corrections, etc.)

Angles (azimuths, inclinations, declinations, compass/clinometer corrections, etc.)

Note that a measurement (or FS/BS pair) is always entered as a single token; there is no space between any of the separate components.  An entry like "10 f" instead of "10f", for example, will trigger an error message during compilation.  Character case, however, doesn't matter; "10.5F" is equivalent to "10.5f".  The context will determine whether or not certain formats are acceptable.  A quadrant-style bearing like N10E, for example, would not be accepted as an inclination.  Neither would a number outside the range -90 to 90 (after conversion to degrees).  There are, in fact, many forms that could technically be interpreted as legitimate values (365d, N-10W, 30.5:20, 10.0i6, etc.) but are instead viewed by the program as possible data entry errors. Even a sign (plus or minus) on a distance or azimuth is considered suspect.  All such unlikely forms will generate an error message.

Finally, a special token, a sequence of two or more successive minus signs (e.g., "---"), can be used where appropriate to indicate that an actual measurement was not taken and that certain assumptions can be made regarding its absence during processing.  Examples might include inclinations in a water passage (assumed zero), azimuths of pure vertical shots, missing LRUD distances, and absent foresights or backsights.  If not followed by other line items, blank fields can sometimes serve the same purpose.