Fits a degree 3 (cubic) curve to a degree 1 (linear) curve. Typically you use  after you import curves, surfaces, and digitized data from other products in which the curves have curve degree 1. 
         
         
          
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                      The tolerance sets how much accuracy is maintained between the original and fit of interpolated curves. 
                       If set to , the fit is accurate to within 0.010 units, by default. 
                         lets you change the tolerance value in the  box.
                      
 
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                      The  information is read-only. You can click the arrow button to select the curve and edit it with the .
                      
 
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                      See Use Tolerance above for details.