To create a math plot showing the summation as stacked areas in Grapher, follow these steps.

1. Click the Graph in the Object Manager to select it.
2. Click Graph Tools | Add to Graph | Math Plot. By default, a summation plot using each of the applicable plots in the graph will be created.
3. Click the Math Plot in the Object Manager.
4. In the Plot tab of the Property Manager, click Edit in the Plot equation field. The Math Plot dialog will open.
   
   
5. Adjust the Plot equation using the plot Variable in brackets and the listed Operator and Function options listed. For example to create a stacked area plot:
   
   
   
6. Click Apply to view the results on the graph and then click OK to close the dialog.
   
   

To change the area fill:

1. Click Math Plot in the Object Manager. 
2. In the Property Manager, click the Fill tab. 
3. Change the Pattern to your desired pattern and adjust the other properties as desired. 

Updated May 2023