Set Points

Number of Points

Type in the number of random points that you would like to create within the study area. Click the Enter button. A green tick mark will appear and the Minimum Distance input field will be activated.

Minimum Distance

Type in the minimum distance that receptor points should be apart. This must be a number greater than zero. The unit of the distance is the same as the map unit of the projected coordinate system of your study area. It is recommended to use a minimum distance equal to or greater than 2x the smallest buffer size used in the LUR model. Click the Enter button. A green tick mark will appear and the Next > button will be activated. This completes the Receptors from Random Points step.

If the LUR models contain predictors that are derived from the Inverse distance, Inverse distance squared, Value * Inverse Distance, or Value * Inverse distance squared to the nearest feature, then any receptor points located on top of the nearest feature will result in a division by zero error, because the distance is zero. To prevent this, the wizard will check if the LUR model contains an Inverse distance, Inverse distance squared, Value * Inverse Distance, or Value * Inverse distance squared predictor. If this is the case, the wizard will remove any receptor points located on top of the relevant features. The warning message "Invalid receptor points. See log for details." will appear and the Apply_LOG will record which predictor variable resulted in the removal of receptor points. The Apply_LOG will also record the initial and final number of receptor points used.