XY Distance

[Luke_Vancleave]

Hi,
I’m having difficulty getting Distance() to work with coordinates from two fields with the XY type. When I make two virtual columns that take these same fields and make them LatLong type, distance() functions. Can Distance() only be used with Lat/Long? Any advice? thanks!

[Steve]

Luke_Vancleave:

Can Distance() only be used with Lat/Long?

Yes.

[Luke_Vancleave]

Hmm, I’m not getting any result when I’m trying it. In my game I have players and Creatures. The player’s info is on its own sheet and has an XY field called [Player Character World Location]. Then in a separate sheet, I have a list of creatures and they all have an XY field called [World Creature World Location].
In the first picture, I created a virtual column on my creatures sheet that I’m trying to have measure the distance between that creature and the player’s character.

Here in the next picture, I’ve also added a virtual column called Player Location that I used the same expression in the previous picture to grab the Player Character’s XY location (just to make sure that was indeed getting the right information. But my distance is still zero. Any Advice?

[Fabian_Weller]

Hi @Luke_Vancleave as you see in the Customer Support, DISTANCE() can only be computed between LatLong data types (not XY).
It calculates the distance in km.

https://www.appsheet.com/Support?q=distance&hPP=10&idx=help&p=0&is_v=1

Please read this article under “Mappable Types” to understand the difference between LatLong and XY.

help.appsheet.com

Column Types: Diving Deeper

Learn more about each column type you can have when structuring your columns.

@Steve XY() and Distance() should be updated

[Luke_Vancleave · Accepted solution]

Thanks, I made a work around for myself. I make two virtual columns called [Location 1 X] and [Location 1 Y] and then use the expressions Lat([location 1]) and Long([Location 1]). Then I do the same for my other location [Location 2]. Then (Since I was trying to make an expression where objects wouldn’t appear if their location was too far apart, I made an expression more like
Not(
Or(
OR(
([Location 1 X]-[Location 2 X))>5
,
([Location 1 X]-[Location 2 X))<-5
)
,
OR(
([Location 1 Y]-[Location 2 Y))>5
,
([Location 1 Y]-[Location 2 Y))<-5
)
)
)

[Fabian_Weller]

Here is what you can do:
Add a Virtual Column with Type LatLong with the expression:
LATLONG(LAT([XY]),LONG([XY]))

Then you can use the DISTANCE() expression.

I don’t know how much sense this makes for your usecase, but you can try

[Luke_Vancleave]

I tried that initially but this ran into a distortion because the coordinates of an XY are a grid on a flat plane and the coordinates of LatLong are on a sphere (where things get distorted more towards the poles). you can see my other reply here for my work around.

[Steve]

en.wikipedia.org

Pythagorean theorem

In mathematics, the Pythagorean theorem, also known as Pythagoras's theorem, is a fundamental relation in Euclidean geometry among the three sides of a right triangle. It states that the area of the square whose side is the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares on the other two sides. This theorem can be written as an equation relating the lengths of the sides a, b and c, often called the "Pythagorean equation": where c represents the le...

[Fabian_Weller]

Awesome @Steve I learned this when I was 15 years old and didn’t remember

[Fabian_Weller]

Very cool @Luke_Vancleav. May I ask you to share some screenshots of your App?
Sounds like an interesting XY usecase.

[Luke_Vancleave]

Absolutely!
So I’m trying to make an RPG sorta game inspired by a loose role play group I was a part of like ten years ago. I wanted to create a world that player’s characters could physically exist in with non player entities and mechanics.

One of these was that I wanted player’s characters to be able to “Hunt” prey but to gamify this I wanted prey to only appear if they were within “Sight Distance” of the player. So I have one table of Player Characters with XY coordinates and another table of Prey with XY coordinates (which adds new rows daily to replenish numbers of prey).

So I needed to make the Show? expression for the Prey[XY] have an expression based on the distance between them and the player. So I came up with this solution.
It’s still not ideal because Distance() calculates things in a radius (which I would prefer and might need for other applications) and this method checks in a square around the Player Character.

[Fabian_Weller]

Your map view looks like the usual Google Maps Aerial view.
But you say you are using XY. So did you take a Screenshot from Google Maps Aerial View and use this image as the XY’s Background image?
Why don’t you use LatLong column type? I don’t see the need of XY here, but I’m happy to learn

[Luke_Vancleave]

Ah, that would be a little confusing. I’m using this image as a stand-in until I have one of my artist friends create a game world map to have it set in. This particular image is nice because it’s high resolution so while it cover the area of about a mile square, I can zoom into an area around a city block without it getting blurry. I’m still working out what scale I want the game world to operate in.

[Fabian_Weller]

You can use DISTANCE() with XY values. You just have to convert them to LatLong.

Multi Select in Map View Tips & Tricks 💡

We cannot do bulk select in map view Here is a way to somehow multi select map pins. Please see my Test App “Bulk Select” on my Portfolio. When you select / deselect an pin, it jumps to the nearest next pin. With that you save one click When you’re done it jumps back to the detail view. It uses the DISTANCE() expression to calculate the nearest pin. When you use XY (like in my sample) you have to convert the XY value to a LatLong. Simply by using a VC with column type LatLong. [M…

[Luke_Vancleave]

If I recall I tried something similar when I was still working on this project. But lat/long wasn’t directly comparable to XY because XY is describing a flat grid and LatLong is a point on a globe. So the result would be more skewed than you might think it would be