topic Re: Help with Attribute Rules - Finding Nearest School in Attribute Rules Questions

Help with Attribute Rules - Finding Nearest School

Robswann — Fri, 20 Aug 2021 13:40:37 GMT

Hello, I am trying to use the attribute rules in my polygon feature to find the nearest school to each polygon. I have the following below, but it seems to be returning a school further away. Can someone please help?

Thanks in advance.

var CURRENTSCHOOLS = FeatureSetByName($datastore, "ELEMENTARY_SCHOOL", ["School_Nam"]);
VAR SEARCHDISTANCE = 10;
VAR SCHOOLINTERSECT = INTERSECTS(CURRENTSCHOOLS, BUFFER($FEATURE, SEARCHDISTANCE, "MILES"))
VAR MINDISTANCE = INFINITY
VAR FSCHOOL = FIRST(SCHOOLINTERSECT)
IF (FSCHOOL == NULL) RETURN ""
IF(SEARCHDISTANCE < MINDISTANCE)
RETURN FSCHOOL.SCHOOL_NAM

Re: Help with Attribute Rules - Finding Nearest School

JohannesLindner — Fri, 20 Aug 2021 13:53:25 GMT

var CURRENTSCHOOLS = FeatureSetByName($datastore, "ELEMENTARY_SCHOOL", ["School_Nam"]); VAR SEARCHDISTANCE = 10; VAR SCHOOLINTERSECT = INTERSECTS(CURRENTSCHOOLS, BUFFER($FEATURE, SEARCHDISTANCE, "MILES")) IF(SCHOOLINTERSECT == null || COUNT(SCHOOLINTERSECT) == 0) { RETURN "" } VAR MINDISTANCE = INFINITY VAR NEARESTSCHOOL = "" FOR(VAR SCHOOL IN SCHOOLINTERSECT) { VAR DIST = DISTANCE(SCHOOL, $FEATURE) IF(DIST < MINDISTANCE) { MINDIST = DIST NEARESTSCHOOL = SCHOOL.SCHOOL_NAM } } RETURN NEARESTSCHOOL

Re: Help with Attribute Rules - Finding Nearest School

Robswann — Fri, 20 Aug 2021 14:04:18 GMT

Thanks so much Johannes! I had an error but made the change from MINDIST TO MINDISTANCE line 12 and i worked..

I hate to ask, but would there be a way to add a rule that returns the distance from the polygon to the nearest school? Thanks again

Re: Help with Attribute Rules - Finding Nearest School

JohannesLindner — Fri, 20 Aug 2021 14:09:11 GMT

Sure. Same as this rule, but return MINDISTANCE instead of NEARESTSCHOOL.

Re: Help with Attribute Rules - Finding Nearest School

Robswann — Fri, 20 Aug 2021 14:14:45 GMT

Thanks again!

Re: Help with Attribute Rules - Finding Nearest School

Robswann — Fri, 10 Sep 2021 15:53:15 GMT

Would it be possible to find the nearest schools within a certain school district only. The School District that would be referenced would be a entered field within the feature, Thanks

Re: Help with Attribute Rules - Finding Nearest School

JohannesLindner — Mon, 13 Sep 2021 06:04:02 GMT

// change: load your school district field var CURRENTSCHOOLS = FeatureSetByName($datastore, "ELEMENTARY_SCHOOL", ["School_Nam", "School_District"]); // change: filter schools by district var district = $feature.School_District if(district != null) { CURRENTSCHOOLS = Filter(CURRENTSCHOOLS, "School_District = @district") } // rest stays the same VAR SEARCHDISTANCE = 10; VAR SCHOOLINTERSECT = INTERSECTS(CURRENTSCHOOLS, BUFFER($FEATURE, SEARCHDISTANCE, "MILES")) IF(SCHOOLINTERSECT == null || COUNT(SCHOOLINTERSECT) == 0) { RETURN "" } VAR MINDISTANCE = INFINITY VAR NEARESTSCHOOL = "" FOR(VAR SCHOOL IN SCHOOLINTERSECT) { VAR DIST = DISTANCE(SCHOOL, $FEATURE) IF(DIST < MINDISTANCE) { MINDISTANCE = DIST NEARESTSCHOOL = SCHOOL.SCHOOL_NAM } } RETURN NEARESTSCHOOL

Re: Help with Attribute Rules - Finding Nearest School

Robswann — Tue, 14 Sep 2021 15:56:32 GMT

Thank you for your response, i have been working on getting what you suggested to work, but still no luck. I Probably didnt provide enough info:

//Note: ELEMENTARY_SCHOOL is the feature that has all the schools

// Note: DISTRICT_1 is the field located in ELEMENTARY_SCHOOL that lists the School District the school is located in,

//Note: var district = $feature.School_District - Is the field that contains the School District to search within and is the feature class named PROPERTIES (The layer with the Attribute Rule)

The below returns a null value everytime, not sure what I am doing wrong. Thanks

// change: load your school district field
var CURRENTSCHOOLS = FeatureSetByName($datastore, "ELEMENTARY_SCHOOL", ["School_Nam", "DISTRICT_1"]);
// change: filter schools by district
var district = $feature.School_District
if(district != null) {
CURRENTSCHOOLS = Filter(CURRENTSCHOOLS, "DISTRICT_1 = @district")

}
// rest stays the same
VAR SEARCHDISTANCE = 30;
VAR SCHOOLINTERSECT = INTERSECTS(CURRENTSCHOOLS, BUFFER($FEATURE, SEARCHDISTANCE, "MILES"))
IF(SCHOOLINTERSECT == null || COUNT(SCHOOLINTERSECT) == 0) {
RETURN ""
}
VAR MINDISTANCE = INFINITY
VAR NEARESTSCHOOL = ""
FOR(VAR SCHOOL IN SCHOOLINTERSECT) {
VAR DIST = DISTANCE(SCHOOL, $FEATURE)
IF(DIST < MINDISTANCE) {
MINDISTANCE = DIST
NEARESTSCHOOL = SCHOOL.SCHOOL_NAM
}
}
RETURN NEARESTSCHOOL

Re: Help with Attribute Rules - Finding Nearest School

JohannesLindner — Wed, 15 Sep 2021 08:38:36 GMT

If the rule returns an empty string, it means it didn't find a school in teh specified search radius. If it worked before adding the filter, then the problem is probably in the filter.

make sure that ELEMENTARY_SCHOOL.DISTRICT_1 and PROPERTIES.School_District are of the same data type
make sure that School_District is a value that can actually be found in DISTRICT_1
include better log messages (at least temporarily)