For anyone curious about what is going on here, I had been trying to implement a great distance search using the basic cosine formula for such. My inputs were returning out of bounds because the arc cosine function was not finishing with a result that was within range of its bounds. I have since changed my methodology and uncovered some bugs from my original conception. Instead of the basic cosine formula, because I couldn’t find a way to normalize the resulting calculations in SQL, I implemented a Haversine formula for calculating the great circle distance.

Here’s what I ended up with that works:

func DistanceSearch(lat float64, lng float64) {
Db, err := gorm.Open(DATABASE, CREDENTIALS)
if err != nil {
log.Panic(err)
}
defer Db.Close()
type DistanceStruct struct {
OrganizationID int
Name string
Street string
Lat float64
Lng float64
Distance float64
}
selected := DistanceStruct{}
Db.Raw("SELECT organization_id, street, lat, lng, 2 * 3961 * asin(sqrt((sin(radians((lat - $1) / 2))) ^ 2 + cos(radians(lat)) * cos(radians($1)) * (sin(radians(($2 - lng) / 2))) ^ 2)) as distance FROM addresses GROUP BY organization_id, street, lat, lng HAVING 2 * 3961 * asin(sqrt((sin(radians((lat - $1) / 2))) ^ 2 + cos(radians(lat)) * cos(radians($1)) * (sin(radians(($2 - lng) / 2))) ^ 2)) < 50 ORDER BY distance", lat, lng).Scan(&selected)
fmt.Printf("%v \n", selected)
}