Entering Graph Definition

For each type of graph definition there are reserved names of variables, which should be used in definitions. By default the names are

Cartesian                                x

Polar                                       fi

Parametric                              t

Level line                                x and y

Directional Field                   x and y

Broken Line                           none

Array, 3-spline                       none

You can fully define graph in Graph Window. For instance, in Cartesian coordinates you can type definition like

3*sin(2*x)

Alternatively, you can pre-define necessary expressions in Calc Window and assign them to variables. For example, assign

f:=3*sin(2*x)

in Calc Window and then define graph simply as f.

You can combine both methods. For instance, if you want to observe how values of coefficients affects graphs shape, you can enter definition as

a*sin(b*x)

and define values of a and b in Calc Window:

a=2 b=3

Each time you amend values of a or b the graph is re-plotted.

The rules of interpreting graph definition are

• If graph definition contains other variables, besides arguments, their values are substituted from the list of defined variables.
• The values of arguments are not substituted, even if they are defined 
• In general, the rules of substitution are similar to evaluation rules in Graph Window with restriction to substituting of arguments. It means that some variables can be defined in terms of other variables, etc.
• If after substitution there remains some variables, except arguments, the definition is considered invalid and graph is not plotted.
• If you alter value of any involved variable in Calc Window, ArtSGraph immediately redraws all affected graphs

After type of definition is selected you enter definition in a line of Graph Definition Zone. Status line reminds you of proper format for the selected type. To complete graph definition press Enter and ArtSGraph will plot the graph. In case of an error in definition, fix it and press Enter again.