Use the following options to set what happens when you select .
The tolerance sets how much accuracy is maintained between the original and fit of interpolated curves.
If set to Global, the fit is accurate to within 0.010 units, by default.
Local lets you change the tolerance value in the Positional Tolerance box.
The Input Curve information is read-only. You can click the arrow button to select the curve and edit it with the Attribute Editor.
See Use Tolerance above for details.