Stacho

> there is a possibility to specify reduction ratio for extended elevation (0 = vertical, 100 = normal left/right) - just use "extend <number>"

I have made this work, by placing ‘extend <number>’ statements in-line with the survey data, but that seems to be the only way it will work.  Every combination I could think of with the extend controls in a separate centreline or block results in an error.

For an example I have managed to make this extended centreline…

…into this by using strategically placed ‘extend 50’, ‘extend 100’, and ‘extend 75’, as well as an ‘extend vertical’.  It now matches more closely what one would expect by looking at the plan view.

So it works very well, but the difficulty I have is that to make the extended elevation control manageable, it needs to be separated out (in one place) from the survey data, but now any control of the extend ratio must be in-line with the data.  This makes it very confusing and difficult to manage. 

Is there any chance that the ratio could be controlled by statements in separate centrelines, as with left/right/vertical etc?

Maybe by allowing the form ‘extend [left <ratio>] <station1> <station2>’ as an equivalent to the in-line statements ‘extend <ratio>’ and then ‘extend left’?

(I am thinking of similar syntax to ‘export map -projection [elevation 290 deg]’ where the square brackets are required if the default is not what is wanted).

The extend ratios are applied to splays as well as to legs, which is usually desirable, except sometimes where the ratio approaches zero.  If the user is to control splay ratios separately to the legs, then I guess the only option is to put the extend ratio statements in-line.

And one more thing.  The range is limited from 0 to 100%.  If we are going to allow distortion of the extended elevation, then I think the upper limit should be something like 150% or 200%.

Bruce