Using Fields Within Field Formulas
Comments(5) I received this question from Erik about creating a Northing & Easting block with fields. Here is his question:
I find your post extremely helpful but I do have a question. I need my northing and easting to read a custom ucs (not world). Example, I’m giving a contractor a benchmark to work from which in world ucs is: N: 12213.19 E:-33516.2 but for ease we are setting that coordinate as N:0.00 and E:0.00 by making a custom layout ucs.
When I test the block it will only read out and display the world ucs even when I’ve set it to my custom ucs. Any thoughts? I want to place this block and have it read my custom ucs coordinate system instead of the world…
Great question Erik!
I don’t think moving the UCS affects the coordinates in the field. But I dug in and found a way you can use a field within a field formula. The concept would be to take the Northing & Easting fields and use them in a formula to present modified Northings & Eastings.
Here is how I figured it out.
I started with the instructions contained in this previous blog post to create a Northing/Easting block using fields. You will notice that when you create a field there is a “field expression” at the bottom of the field dialog box. I figured out that that code defines the current field and you can copy that code and use it in a formula.
In this case, I created an “Easting” field and copied the field expression:
Then I selected the “Formula” field name and pasted the field expression into the formula box. Notice it no longer looks like a complicated formula, but is displayed as 0.00 (this looks like it represents the field’s format and precision):
Then I created a simple formula (modify according to your needs):
Click the “evaluate” button and more options will appear:
After you perfect the formula and set the format and precision, you will have a modified “Easting” coordinate. Repeat these steps to modify the “Northing” field as well.
Using fields in field formulas extends the power of fields even more! Let me know if this tutorial is helpful and how you make use of it. I’m excited to hear your ideas too!
I want to draw a plane object like a conveyor on a plane grid with a local plane coordinate system. then i would like to take one point and an orientation from my local object and give it world coordinates. I then would like to be able to add data using either coordinate system. For example using a theodolite in the local grid or the GPS in the world grid. (its not my GPS data so i can’t just create the local coord system in the instrument)
Tom,
You would probably be better off using Map 3D or Civil 3D to accomplish this.
Hi Josh,
Funnily enough a few weeks ago i stumbled across the “field” button in the attribute dialog box and thus created the exact block(nearly)as you have, but had told the lads in work it would only work to world ucs so well done on this twist, very clever!!
Just wanted to let you know that the whole copying/pasting of the forumula expression isn’t necessary. You can nest fields inside of formulas (notice the “Insert Field” In the drop-down menu in your second screenshot)
Thank you! Good tip.