Use the Time History Function Definition form to define a time history function based on a text file of time history function data.
Function name edit box. Specify the name of the function or use the default.
Function file display box. Click the Browse button in this area to display the Pick Function Data File form and select the name of the text file that includes the time history function data. The name of the selected file will appear in the File Name display box. Click the View File button to display the selected file in text format in WordPad.
The program reads the time history function file as follows:
First, it skips the specified number of header lines.
Next, it checks to see if a line has a $ symbol as the first character. If it does, the program skips to the next line.
If the first character on the line is not a $ symbol, the program reads the information on the line.
If the line is blank or when the end of the file has been reached, the program stops reading and closes the file.
Typically, the program does not import the file into its database. It simply maintains a link to the file location. Thus, if either the time history function file or the .SDB file is moved to another location, the program may be unable to locate the function file. If the Convert to User Defined button is clicked, the program imports the time history into its database file, making the data always available to the model.
Important: Do not click the Convert to User Defined button until all information has been specified in the Function File, Values are and Format Type areas.
Header Lines to Skip edit box. When reading the function file, the program skips the number of lines at the top of the file indicated in this edit box.
Prefix Characters per Line to Skip edit box. When reading the function file, the program skips the number of characters specified in this edit box at the beginning of each line.
Number of Points per Line edit box. Specify how many function values or sets of time and function values are specified on each line. Additional data on each line will be ignored.
Values are area. Specifies whether the text file contains pairs of Time and Function Values or Values at Equal Intervals of (i.e., only function values that are spaced at equal time intervals). If the Values at Equal Intervals of option is selected, use the edit box to specify the time interval.
Format type options. The format type can be specified as Free Format or Fixed Format. In free format, items on the lines can be separated by spaces or tabs. For a fixed format type, specify the number of characters per item. Each item on a line is assigned the same number of character spaces. The program begins counting the spaces after it skips the number of prefix characters specified in the Prefix Characters per Line to Skip edit box.
Function graph area. This area displays a graph of the function. First specify all of the data in the Function file, Values are and Format type areas. Then click the Display Graph button in the Function Graph area of the form to display the graph of the function.
Run the mouse pointer over the function graph and a dot appears along the line representing the time history function. The coordinates of the dot are reported in the box just below the graph.
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Access the Time History Function Definition form to define a time history function based on a selected file as follows:
Click the Define menu > Functions > Time History command, to display the Define Time History Functions form. Then do one of the following:
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