Need to figure distance between two points/lines.
An example. The first line starts at elevation 100 and ends at elevation 105. A point in the middle of this line at 150 feet would obviously be 102.5. The second line in the middle at 150 feet has an elevation of 103.5. This point is 2.5 tenths of a foot too high and will need to be changed to 103.25 to be within spec.
A second example would be on the second line 10 feet in, it is 3 tenths below the first line but 200 feet in, it is 6 tenths above the first line. This is 1.5 tenths out of spec and one of the points will need to be changed. If the both of the elevations on the end points of the first line were 100, this would be easy to check. Alas, its not always like this. What do I need to google to figure this out or what formula do I need to use? It would be great if I could quickly plug in my numbers and calculate it as I have dozens and dozens to do. Thanks.
Edit:Perhaps it would help if I outlined the actual scenario I am doing. This is for building a 3d model for the dirtwork on a solar farm. Each array of solar panels is sitting on piles driven into the ground. Each array is 300 feet long with piles every 24 feet. The piles have 7.5 tenths of tolerance to adjust for the ground. The engineers have given us a model that has problem areas. The picture I posted has a straight line from elevation 601 to 607. The other line with curves is an example of the natural ground that the piles will be driven into and which may need to be changed in relation to the first line. This is a profile view.
https://flic.kr/p/2n4Dr5N

Your question is a bit vague. What do you mean by a line starting at elevation 100? The ycoordinates is 100? What is the xcoordinate of the point? In the attached email you have a straight line and a curve, not two line. It would help if you just draw a careful picture for one of the scenarios you mentioned above. Add a Comment

Perhaps it would help if I outlined the actual scenario I am doing. This is for building a 3d model for the dirtwork on a solar farm. Each array of solar panels is sitting on piles driven into the ground. Each array is 300 feet long with piles every 24 feet. The piles have 7.5 tenths of tolerance to adjust for the ground. The engineers have given us a model that has problem areas. I am trying to fix them. I will post a second picture for the first example.

I dont know how to change the picture. It won't let me when I try to edit it.

Yes, I good picture with detailed information on it would help me understand the problem.

Just upload a second one.

Put a Flickr link in my last edit, Philip.

The picture is very clear now. Could you please clarify what is the unknown that you want to compute in the attached picture?

Is the unknown what you call "Distance apart " in your picture?

Yes thats correct. I need to be able to figure the distance apart on on several points between line 1 and 2 quickly and easily to make sure their average from line 1 is never more than 7.5 tenths. For instance, line 2 may be 3 tenths below line 1 20 feet from start but 6 tenths above it 200 feet from the start of line one. This would need to be fixed.

Wait, so you know the horizontal distance and need to compute the vertical one? I feel like it would be very easy to answer the question, but I don't understand exactly what you mean.
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