Once you've got the basics of creating and editing a map down, filters are the next step to increase your mySidewalk mastery.
Most maps don't need filters, but they are handy tools that can increase the detail and information you can display in a map.
What Can Filters Do?
Filters can:
Limit the area shown on your map by focusing on specific parts of a variable (e.g., showing only census tracts with low access to cars in a layer about low access to healthy food).
Add more detail or context by displaying specific attributes of a variable (e.g., adding specific disabilities in a map showing the percentage of residents with disabilities).
Show the numerator for data that has been normalized (turned into percentages).
Adding Filters
To add filters to a map layer:
Click Filters next to Style in the edit panel.
Choose between two options:
Select a dataset: Pick a dataset other than the one currently visualized.
Good if you want to add data that your readers will see when they mouse over the map.
Most common.
Add a filter: Filter the dataset that is visualized in your layer.
Good if you want to only show geographies that fit certain criteria for the data you've already visualized in the layer.
Now you can adjust the other settings:
Filter Menu Options
Filter Type
Filter Conditions
You can have more than one filter on a map layer.
Filter Menu Options
Once you’ve added a filter, you can modify what data it's using or how it appears with the filter menu. Here’s a breakdown of the options:
Eye Icon: Toggle the filter on or off.
Change Data: Select a different dataset for the filter. The current dataset and its source are shown next to this option.
More Options:
Change the label of the filter. This appears when clicking on the map.
Normalize the data and adjust the unit if needed.
Change the format and number of decimal places.
Ex. if you normalize data, you likely want format to be "ratio as percent."
Filter Type
There are two filter types:
Percentile: Used to show things like census tracts in the top 20% of median income.
Assigns each subgeography a number between 0 and 100 for the purpose of the filter.
When clicking on the map, it will still show the original data.
Value: Used to show things like census tracts above $40,000 median income. Uses the original value from the data.
Filter Conditions
You can apply filter conditions to narrow down what appears on your map. For example, you can filter census tracts with values in the bottom 25% or top 25%. You can also toggle filter conditions on or off using the eye icon.
Condition Operators
Has Any Value: Adds information to your map when readers mouse over it.
Has No Value: Restricts the map to areas with no data in the dataset.
Range: Restricts the map by setting a minimum and maximum value.
Between: Restricts the map to values between a chosen range (excluding the minimum and maximum).
At least/At most: Restricts the map to areas with values above or below the chosen threshold.
Greater than/Less than: Restricts the map to values above or below a threshold (excluding the threshold).
Example: "Greater than 1" will show all areas with a value higher than 1. Areas with a value of exactly 1 would not be included. "At least 1" will show all areas with a value of 1 or higher.
Equal/Not equal: Restricts the map to areas that do or do not exactly match the value you choose.
Pro Tip:
There are two ways you can apply your filters to the map: Geographies must meet ALL conditions, and Geographies must meet ANY conditions.
If you are adding information to your map when readers mouse over it, try selecting ANY conditions with both "has any value" and "has no value" as operators. This keeps subgeographies that are missing your filter's data on the map.
Saving Your Filters
When you're done making changes to your filter, click Done to apply your changes.
Pro Tip:
You can duplicate layers once filters are set up, allowing you to make small changes to see how they impact your map without starting over.