Strange Results with Text Insert Field when using Item Type Definition

Try System.String.Format. Check help. 

System.String.Format ("{0:#.#}", System.Math.Round(System.Math.Sqrt(this.GetElement().Segments[0].DeltaX ^ 2  + this.GetElement().Segments[0].DeltaY ^ 2),1)) 

I downloaded your DGN file and here is the updated expression and it works.

System.String.Format ("{0:#.#}", System.Math.Sqrt(this.GetElement().Segments[0].DeltaX ^ 2  + this.GetElement().Segments[0].DeltaY ^ 2))

3D Imperial Design-Updated.dgn

Hi Leonard,

I will concede that the string format is working for the simplified case of the 2D length of a line for the item type definition noted in my original post.

If you are up for another challenge, any ideas why I can't display an item type instance data for a more complicated situation? Here is the situation. I want to create an item type definition called Slope and I then want to use a Text Field to display the value of Slope. Here is the expression I am using for Slope.

System.String.Format("{0:#.#}", (System.Math.Abs(System.Math.Round(this.GetElement().Segments[0].DeltaZ, 2)) / System.Math.Round(System.Math.Sqrt(this.GetElement().Segments[0].DeltaX ^ 2  + this.GetElement().Segments[0].DeltaY ^ 2), 1) * 100))

As noted in the screen grab image above (and the attached DGN file), the purple colored text that is attempting to graphically display the item type instance data of Slope seems "unresolved" (i.e., it only shows ###).

3D Imperial Design-Updated_V2.dgn

Check the following expression.

System.String.Format("{0:#.##}", this.GetElement().Segments[0].DeltaZ / System.Math.Sqrt(this.GetElement().Segments[0].DeltaX ^ 2  + this.GetElement().Segments[0].DeltaY ^ 2) * 100)

3D Imperial Design-Updated_V2 - Updated.dgn

Check the following expression.

System.String.Format("{0:#.##}", this.GetElement().Segments[0].DeltaZ / System.Math.Sqrt(this.GetElement().Segments[0].DeltaX ^ 2  + this.GetElement().Segments[0].DeltaY ^ 2) * 100)

3D Imperial Design-Updated_V2 - Updated.dgn

Hi Leonard,

Based on actual read-world construction tolerances, I need to calculate the 3D line slope using the method and assumptions (or input parameters) I mentioned in my message above (Wed Sept 27 11:34 AM). Restated, here are the assumptions and calculation parameters:

• Find the elevation values of the beginning and end of the line. Round these to two decimal places (i.e., X.XX). Calculate the elevation difference between these two points.
• Query or calculate the 2D length of the line. Round this value to one decimal place (i.e., X.X).
• Calculate the slope of the line (i.e., Rise / Run). Then round the slope value to one decimal place.

This is a real world scenario for linear transportation projects such as the design and construction of ADA complaint pedestrian access ramps. Here is an example:

Please note that there are subtle but important differences in the result of the calculated slope values using the method I outlined above, versus your proposed solution that allows MicroStation to use as much precision as possible (e.g., full double precision values of elevations and line lengths, etc.), and then at the very end attempting to round up the slope value. For example:

• 1.6% (my calculation process) versus 1.5% (your proposed solution)

Due to ADA compliance, and some state and DOT regulations, for certain aspects of pedestrian ramps the 1.6% slope would be non-compliant and if built and installed this way, the ramp would need to be torn out and reconstructed.

Can you or someone else at Bentley check or confirm why MicroStation cannot display the instance data of the item type definition Slope as noted in this screen grab?

The expression is working correctly in the item type, and it displays correctly in the element properties window, but there appears to be a bug within MicroStation for the step that involves the "lookup or query" of the corresponding Text Field.

Thanks for sharing all the details. I am checking with Development on this.

The problem is with Round function which results to 0. The Round function does not round decimal values.
System.Math.Round(this.GetElement().Segments[0].DeltaZ, 2)

To round the decimal values, I had to use the following expression which results to 0.4. Check link
System.Math.Round(System.Math.Abs(this.GetElement().Segments[0].DeltaZ) * 100)) / 100

Check the attached DGN, I split the expressions for easy handling.
MyLib > LinearProp
Rise - System.Math.Round(System.Math.Abs(this.GetElement().Segments[0].DeltaZ) * 100)) / 100
Run - System.Math.Sqrt(((this.GetElement().Segments[0].DeltaX ^ 2) + (this.GetElement().Segments[0].DeltaY ^ 2)))
Slope - (this.GetItem("DgnCustomItemTypes_MyLib:LinearProp")["Rise"] / this.GetItem("DgnCustomItemTypes_MyLib:LinearProp")["Run"]) * 100
Slope - (this["Rise1"] / this["Run"]) * 100

5383.test.dgn

Thank you Leonard! The research you performed, and in particular, the link you found with the solution to the issue with that Math.Round function did the trick!

I implemented your solution by updating my item type property definitions. To provide full robustness, I even incorporated the ability to change the "precision" (number of decimal places) for the rounding of the Rise and Run calculations.

Please note that that the best work-around I found for the rounding of the Slope calculation is to use the System.String.Format function, and I even provided flexibility to make this adjustment after applying the item type to the 3D line. For example:

• To round slope to one decimal place: {0:#.#}
• To round slope to two decimal places: {0:#.##}
• Etc.

In the event that anyone else is following along, or would find this useful, attached is the updated DGN file with the item type property definitions.

Thanks again Leonard for all your help with this solution!

3D Imperial Design-Updated_V3.dgn