To Edit a Trace Name
Insert a Chart component, define the X and Y expressions, plot the trace, and then double-click the plot area to open the PTC Mathcad Chart application.
The chart below appears in the graphics area:
The PTC Mathcad Chart application allows you to edit the name of a trace as it appears in the legend.
To edit the trace name:
1. Click the Chart tab, the Chart icon 
, and the Legend tab.
, and the Legend tab.2. Select the Chart Legend checkbox.
The legend is added to the plot showing the default trace name:
3. Click the trace icon 
, and then click the Setup tab.
, and then click the Setup tab.4. Select the Setup checkbox to enable the editing of its fields.
5. Edit the default value of the Name field from 1 to another number or text, such as “My Data”. The name of the trace changes accordingly:
Use the same procedure to edit the name of other traces.