Apply flexible data filtering in Grapher

Isolate critical trends and clean up your technical visualizations by mastering the Grapher Data Filter tool. By default, Grapher plots every data point available within your selected worksheet columns. However, you can programmatically exclude specific values, strip out corrupt or NULL data, and isolate precise numeric intervals without altering your raw data files. The Data Filter tool allows you to configure advanced logical expressions, manage multi-column criteria, and use conditional filtering across all data-driven plot types.

Capabilities of the Data Filter

The filtering engine accepts advanced boolean parameters and mathematical syntax, allowing you to manipulate what data displays on your graph:

• Null Removal: Cleanly omit blank cells or specific placeholder values (e.g., -999) from displaying.

• Multi-Criterion Logic: Stack concurrent inclusion or exclusion rules across a single worksheet column or multiple disparate columns.

• Advanced Operators: Deploy comparison symbols ($>$, $<$, $==$, $!=$) and boolean strings (AND, OR).

• Mathematical Support: Incorporate pre-configured algebraic and transcendental functions directly into your equations.

• Universal Compatibility: Apply these parameters globally across data-heavy formats, including Floating Bar, Rose, Wind, Histogram, Q-Q, Contour Data, and Surface Data plots.

To use the Data Filter:

1. In the Object Manager, select one or more plots that use data files as inputs. If more than one plot is selected, the Filters will be applied to all selected plots.
2. In the Property Manager, select the Data Limits tab.
3. Click the Filter button in the Data Filter field.
4. To build filters in the Data Filter dialog:
   1. Click the Add Expression button to add a new filter row. You can either:
      • Type directly into the Expression field
      • Double-click to add elements from the Data, Operator or Function windows
      • Select a previously built filter by clicking the Expression History button
   2. Specify the Action for each filter. You can choose to Filter data out (like the Null option in the old Criteria Filter) or Filter data in (like the Criteria option in the old Criteria Filter). The Filter data in option will plot only the data that match the filter condition; whereas Filter data out filters out data that matches the filter condition.
5. Click the adjacent red X to remove a specific filter.
6. Click the Clear All button to remove all filters.
7. Click OK or Apply to set the filters on the plot.

Critical Rules & Syntax Constraints

• If there's a syntax error, Grapher will issue a warning.
• The effects of the filters are cumulative.
• Specified filters will only be maintained when opening in a previous version of Grapher under the following conditions:
  • Filter-in:
    [Column ..] == Text
    [Column ..] == NumericVal
    [Column ..] > NumericVal OR [Column ..] < NumericVal
  • Filter-out
    [Column ..] == NumericVal
    [Column ..] >= NumericVal AND [Column ..] <= NumericVal