A1.2 FUNCTION ENTRY

 The user  has access to the Function window from the   button. Function entry dialog window is used to define function-like parameters of simulation, such as blocking response or intermodulation rejection. This is how a function entry dialog box looks like:

Table 62: Description of the function options in SEAMCAT


Description

Comments

Constant

In this case the function always returns the same constant value

User-defined

It is defined by a sequence of points (x, y=f(x)) meaning that the input as many values as needed for abscissa and corresponding function response values, paying attention to units shown in the heading of the relevant function definition window



Figure 360: Example on how to edit a user defined function (i.e. like receiver blocking mask)


To introduce a non-constant function, select User-defined item in the Type group box and enter the points defining the function in form of pairs (x, y=f(x)) in the function table.

Note: the range of entered data depends on the type of defined parameter,. For example, for user-defined blocking function, all entered values y=f(x) should be positive. 


The following functions are available in the dialog window:

  • Add: To add a new pair, click on Add button. Pairs are then automatically sorted by increasing x value;
  • Delete: To suppress a pair, click on Delete button;
  • Sym: To symmetrize a function, click on Sym button, this results in generating for each existing pair (x, y) a symmetric counterpart (-x, y), unless it already exists;
  • Load: click on the Load button to import a set of function values from a text file. This file must be formatted to contain one pair (x, y) per line, TAB separated;
  • Save: press the Save button to export the current function table into a text file, e.g. for frequently used functions or for sharing with other users.