This is a data manipulation function for facility_user_dist. This function creates a spread matrix of the distances between each user and each facility. There is an ohca_id column, and then a column for each aed_id, with a given cell being the distance between an ohca in a row, and that column. This distance is converted into an indicator variable, based upon whether that distance is less than the provided dist_indic parameter. In the future I might change the dist_indic function to be optional, but this whole function mainly exists to make it easier to do the computation in the max_coverage function.