New curves are created in any of the following ways:

The Create Curve action may be used to import curve data from a curve data file. See Import Curve Data from an External File, 25. Curve data files, which are ASCII text files stored in directories, can be created by XY Plot as described in Write Curve Data to a Curve Data File, 29. New curves can also be created by systems, applications or editors external to Patran as described in Preparing Curve Data Files, 16. A curve data file contains one or more data sets. Each data set includes the curve data type identifier, data points, and (optionally) the title for a single curve. XY Plot reads a selected data set from the file and stores the data in the model database under the name specified by the user. The standard Patran file extension.xyd is used for identifying curve data files.

The Create Curve action may be used to create a new curve whose name, data type, and data points are specified by XY Plot. In Create/Modify/Display a Curve’s Data Points, 27, the Curve Data Keyboard form is described, which is used to specify the curve data type and data point values.

The originating Patran application (e.g., Results, Fields, Materials, Loads and Boundary Conditions) may be used to write the new curve data including the name, title, data type, and data point set to the model database. These curves are posted to an XY window named XyWindow1. This window, along with the newly created curves, is automatically posted. The curve name assigned by the originating application, as well as the XY window created by the application, is included in XY Plot’s list of defined curves and XY windows. This XY window, and the curves created by the originating application, can be modified with XY Plot.

Regardless of the method used to create the curve, the curve data type identifier must indicate whether data points are defined by a pair of X and Y values (type XY Pairs) or by a single Y value (type Y Data).

Once a curve has been created, the Modify Curve action described in Modify Actions, 39 is used to specify the curve’s plot specifications and display attributes.