Part Modeling > Part Modeling > Datum Features > Datum Curves > Datum Curves from Equations > To Create a Datum Curve from Equations
To Create a Datum Curve from Equations
1. Click Model > Datum > Curve > Curve from Equation. The Curve from Equation tab opens.
2. In the graphics window or Model Tree, select a datum coordinate system or intent datum coordinate system to represent the zero point of the equation.
3. From the list next to , select a coordinate system type: Cartesian, Cylindrical, or Spherical.
4. If required, type a value for the lower limit of the independent variable range in the From box and for the upper limit in the To box.
By default, the independent variable’s range is from 0 to 1, but you can specify any values from –1000000.0 to 1000000.0.
5. Click Equation. The Equation dialog box opens.
6. Type the curve equation as you would type any feature relation. Specify the equation in terms of three coordinate system parameters:
x, y, and z for Cartesian
r, theta, and z for cylindrical
rho, theta, and phi for spherical
Any of these variables can be used as the single independent variable. Only one independent variable is supported.
* 
You cannot use the following statements in an equation that defines a datum curve: abs, ceil, floor, else, extract, if, endif, itos, and search.
7. Click .