LayerLogic: Example Formulas

ORIENTATION CALCULATOR: gives the correct orientation angle for signs to point toward arterial roads.

DATE-BASED ALERT: automatically flags inspection sites as overdue if the current date is later than their due date.

SERVICE ROUTE IDENTIFIER: populates a Smart Field in the Houses layer with the name of the person who delivers mail to that house. Data is retrieved from a Postal Route zone (polygon) map that includes the name of the mail carrier for each zone. The formula determines the mail carrier on the basis of which zone contains the house.

NAME OF NEAREST SCHOOL: gives the name of the nearest school.

MISSING DATA ALERT: makes a field that says “Alert – Missing Date” if an inspection site has a null Due_Date value.

INTERACTIVE DISTANCE FINDER: finds the distance from each apartment building to the nearest selected clinic. To use this formula, select a clinic or clinics or interest and then run a formula update.

POLYGON DISTANCE FINDER: gives the distance from the center of each parcel to the nearest road.

POLYGON-BASED POINT COUNTER: is a Global Calculation that counts the number of crime scenes in our jurisdiction.

VARIABLE BUFFER: populates a field in the Roads layer whose value is the amount of overlap with wetlands within a certain distance called “Impact Distance.” Note that Impact Distance can be an easily-varied Global Input or based on another calculation such as a look-up based on road class.

ELIGIBILITY CRITERIA: populates an Eligibility field in a Habitat layer based on whether the habitat is small enough to meet a maximum size requirement.

JURISDICTION TEST: populates a Jurisdiction field in the Retail Stores layer on the basis of whether the store lies within the city limits.

SLOPE CONVERTER: converts “percent slope” to slope in degrees. For example, a 100% slope is 45 degrees.

DISTRIBUTION GENERATOR: generates random tree heights with an average of 100 feet and a standard deviation of 10 feet.

STEEP SLOPE MEASUREMENT: finds the steepest slope on each parcel of land.

IRRIGATION CALCULATION: calculates the average irrigation rate for each farm based on how much area of each crop it has times the irrigation rate for that crop.