This week during a client project I stumbled upon another challenge: the need to change the marks size on a Map when filtering the data to greater levels of granularity.

As the project overview map had plotted 52500 marks, I had to make them as small as I could to be able to assess cluster patterns around urban areas and motorways; however, when filtering the map and decreasing the number of marks, the size previously stipulated made it very difficult to visualize the marks. The solution would then be, keeping the overview map with the smallest mark size as possible and create an inversely proportional relationship between the number of the marks plotted on the map and their size.

1st –  I created a Calculated Field
size1The calculated field stipulates that the size of the mark will depend of the total number of marks present in the view.

 

2nd –  Dragged the Calculated Field to the Size Shelf

 

3rd – Edited the mark size

size2

And voilà! We now have interactive mark size as we filter our data.

size header

On the other hand, if we wanted to give control of the mark size to the user then, we would:

  1. Create new fields, using calculated fields with an integer (1,2,3 ….)size3
  2. Create a parameter and make the parameter control visiblesize4
  3. Create the calculated field

if [Edit size of mark]=1 then [Edit size 1] elseif

          [Edit size of mark]=5 then [Edit size5] elseif

          [Edit size of mark]= 10 then [Edit size5]

End

  1. Drag the calculated field to the size shelf
  2. Edit the mark size for the size you wishsize5