If you want to make buffer from a point and want to know the distance from the point, follow along on this blog to know how to do this in a simple way

I will be using London burglary crime data. The example that I will use is to make buffer area for crime is 2 kms radius of around 3 prime locations in London i.e., Big Ben, Buckingham Palace and tower of London

First create a crime point using the following calculated field

Figure 1: Crime point calculation

Then you need to make a buffer zone. To do that you need to make a middle point for a buffer radius to start to make a buffer zone. To make that point, you need to make 2 parameters longitude parameter and latitude parameter like as follows

Figure 2: Latitude and longitude parameters

After that you need to make a point which will be the middle point for your buffer. In order to make a point you need to make a calculated field using your latitude and longitude parameter like as follows

Figure 3: Select Point calculated field 

Now you need to assign how big and small your radius for buffer will be. To do that make a parameter for buffer radius to make it dynamic like as follows

Figure 4: Buffer radius parameter

After this step make a calculated field like as follows to make a buffer. You can use kilometers and miles as per your requirement.

Figure 5: Buffer calculated field

After the above steps you will have

  1. Crime point
  2. Buffer
  3. Buffer Radius
  4. Select Point (middle point for buffer radius)

Now click on the crime point to draw out all the crime points in London. To add level of detail add LSAO code to detail marks and now it will mark each and every point individually.

Figure 6: Adding crime points to map

Now adding our fist layer to our map. Drag the buffer on top left corner and you will see an option for “add a layer” like as follows. The purple circle is the radius

Figure 7: Layer 1- Buffer

Now we need to bring in locations of our 3 prime locations in London onto the map. To do so we need the data for these prime locations and by using that we need to make a calculated field like as follows to bring in another layer on our map for our prime locations.

Figure 8: Landmark calculated field

Figure 9: Adding layer 2 of landmark locations

Figure 10: Red points indicate prime locations(landmarks)

Now if we want to calculate all crime points within our buffer from our landmarks, we need to make a line using the calculated field like as follows.  Then add this calculated field as a layer on top of map. Now we will have a buffer zone around our landmarks. In order to view each line separately , add LSAO code to detail.

Figure 11: Calculated field for making line

Figure 12: Adding layer 3- Lines from landmark to crime points

Figure 13: Adding line from landmark to crime points within buffer

Figure 14: Adding level of detail to distinguish single crime point

Now use actions to update longitude and latitude parameter to switch between the landmarks. The configuration for actions is as follows:

Figure 15:Parameter action

Maliha Athar
Author: Maliha Athar