Calculate walk-time isolines for top retail locations

In this example we will create walk-time isolines for selected retail locations. This tutorial includes some examples of simple data manipulation, including filtering, ordering a limiting datasets.
As input data we will leverage a point-based dataset representing retail location that is available in the demo data accessible from the CARTO Data Warehouse connection, but eventually you could use any dataset with store locations or POIs.
Let's get to it!
Creating a workflow and loading your point data
  1. 1.
    In your CARTO Workspace under the Workflows tab, create a new workflow.
  1. 2.
    Select the data warehouse where you have the table with the point data accessible. We'll be using the CARTO Data Warehouse, which should be available to all users.
  2. 3.
    Navigate the data sources panel to locate your table, and drag it onto the canvas. In this example we will be using the retail_stores table available in demo data. You should be able to preview the data both in tabular and map format.
Selecting relevant stores
In this example, we want to select the 100 stores with the highest revenue, our top performing locations.
  1. 4.
    First, we want to eliminate irrelevant store types. Drag the Select Distinct component from the Data Preparation toolbox onto the canvas. Connect the stores source to the input side of this component (the left side) and change the column type to storetype.
  2. 5.
    Click run.
  1. 6.
    Once run, click on the Select Distinct component and switch to the data preview at the bottom of the window. You will see a list of all distinct store type values. In this example, let’s say we’re only interested in supermarkets.
  2. 7.
    To select supermarkets, add a Simple Filter component from the Data Preparation toolbox.
  3. 8.
    Connect the retail stores to the filter, and specify the column as storetype, the operator as equal to, and the value as Supermarket (it's case sensitive).
  4. 9.
This leaves us with 10,202 stores. The next step is to select the top 100 stores in terms of revenue.
  1. 10.
    Add an Order By component from the Data Preparation toolbox and connect it to the top output from Simple Filter. Note that the top output is all features which match the filter, and the bottom is all of those which don't.
  2. 11.
    Change the column to revenue and the order to descending.
  1. 12.
    Next add a Limit component - again from Data Preparation - and change the limit to 100, connecting this to the output of Order By.
  2. 13.
    Click run, to select only the top 100 stores in terms of generated revenue.
Creating walk-time isolines around the stores
  1. 14.
    Next, add a Create Isolines component from the Spatial Constructors toolbox. Join the output of Limit to this.
  2. 15.
    Change the mode to walk, the range type to time and range limit to 600 (10 minutes).
  1. 16.
    Click run to create 10-minute walk-time isolines. Note this is quite an intensive process compared to many other functions in Workflows (it's calling to an external location data services provider), and so may take a little longer to run.