Changing Null Levels (-999) to Zero level for multiple points in a string

RE: Changing Null Levels (-999) to Zero level for multiple points in a string

Chetan.R — Mon, 04 Aug 2014 09:52:53 GMT

ok thank u, sir......

RE: Changing Null Levels (-999) to Zero level for multiple points in a string

ScottBolton — Mon, 04 Aug 2014 09:47:39 GMT

Wouldn't exporting the strings to AutoCAD 3D polylines convert all -999s to 0.000 but leave actual levels unaltered? Then you could import the string back again...

RE: Changing Null Levels (-999) to Zero level for multiple points in a string

Chetan.R — Sat, 02 Aug 2014 07:27:37 GMT

thank you sir, then how to correct the null levels using mx......

RE: Changing Null Levels (-999) to Zero level for multiple points in a string

Jonathan Smith — Sat, 02 Aug 2014 06:25:05 GMT

A null level is a special value that MX knows to ignore when creating triangulations, cross sections etc. Say you created a triangulation from a string with four points, and two of the points had null levels (dimension 3 = -999.000). Only two of the points would be included in a triangulation - the two points with the null levels would be ignored.

So null levels are not "wrong" - and they can be very useful. For example, let's say you surveyed the route of a fence which crossed a ditch - if there was a point on the fence string where it crossed the ditch it should have a null level so that it does not distort the triangulation.

RE: Changing Null Levels (-999) to Zero level for multiple points in a string

Chetan.R — Sat, 02 Aug 2014 05:39:12 GMT

Hi Sir

I am new to Mx-Roads v8i, SS2,can any one tell me what is the meaning of null levels and how to rectify it .

Re: Changing Null Levels (-999) to Zero level for multiple points in a string

Anil P — Mon, 24 Jun 2013 18:49:10 GMT

Hi Per Justsen,

Your example updates all the point levels to zero. But my requirement is only points with null levels in the string need to be set to zero and other points in the string with non-null levels should not updated.

Regards

Anil

Re: Changing Null Levels (-999) to Zero level for multiple points in a string

per justsen — Mon, 24 Jun 2013 13:10:41 GMT

Use op DESIGN to change all levels in an existing string to any level

example

design model = my model

string = xxxxx

desi,my model

120,xxxx,,xxxx,0,7=0

999

field 4, sets the datum level and fiel 7 the offset to the datum level. so in this example all points on string xxxx are on level zero ( 0 )

regards

Per Justsen

Danish Road Directorate

Re: Changing Null Levels (-999) to Zero level for multiple points in a string

Anil P — Sat, 22 Jun 2013 12:41:44 GMT

Hi Mark,

I believe this will solve my problem. I will try this, Thanks for the solution.

Regards

Anil

Re: Changing Null Levels (-999) to Zero level for multiple points in a string

Mark Marnell — Fri, 21 Jun 2013 12:20:43 GMT

Anil

I do not think you can do that in one go - but it is a simple job to do with a text editor.

Step 1. REPO, 992, 2=null - list all the points with null levels to the output window

Step 2. Edit, 021,- paste 021,3=,8=3,9=0,6= as many times as necessary.to your text file

Step 3. Fill in the string name for field 3

Step 4 - give the point number for field 6

Run the file. The whole procedure takes minutes at most.

Mark