negative point level to positive

[neilyj666]

For various reasons I have got a load of site investigation points at negative point levels (representing depth). Is there a quick way of making the negative levels positive so I can create volume surfaces (and then surfaces representing the strata)??

I know I can copy and paste to Excel and reimport but was wondering if anything was built in??

[Alfred.NESWADBA]

Hi,

would this help?

• create first your surface with elevation as they are (< 0)
• create a second surface by drawing a closed polyline at elevation=0 and define that poly as breakline
• now you can create a volumesurface between these two surfaces.

HTH, - alfred -

[AllenJessup]

It depends on what you're trying to do. If you just change the sign it will reverse the surface. Valleys will become peaks. If you just want the surface to be above Zero. Create the surface and then move it up X feet to be above 0. Or move the points that define the surface above 0.

Allen

[neilyj666 · Accepted solution]

I've prepared the data for use with the UKIE Borehole importer tool hence the negative values - the boreholes have been created in profile as expected.

I then need to get the depth to the various strata to be positive, so I can create a surface with levels of CLAY as 0.8, 0.75, 1.1 (or whatever) and then create a TIN volume surface using this CLAY as the base surface with EGL as the comparison. By XMLing this surface out and XMLing it back in with one option unticked (see xmlin.jpg) I get the Base of CLAY surface that reflects the undulations in the EGL that can be used for corridors, grading, profile views etc .

As it turned out I just manually retyped the values into prospector as there were only a few of them but essentially what I need is to take each negative level and multiply by -1 so I'd probably just copy and paste to Excel, change to +ve and bring back into a new drawing.

[AllenJessup]

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@neilyj666 wrote:

 so I'd probably just copy and paste to Excel, change to +ve and bring back into a new drawing.

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That would have been my next suggestion.

Allen