Scripting Guide - SAS

Chapter 12 Scripting Graphs 421
Interactive graphs
)
);
Handle(
mu,
rsqrt2pi / sigma,
mu = x;
sigma = rsqrt2pi / y;
);
Text( {1, .7}, "mu ", mu, {1, .65}, "sigma ", sigma );
In the sample Scripts folder, you can find scripts for showing the Beta Density, Gamma Density, Weibull
Density, and LogNormal Density. The output for the normal is show below. Since we cannot show you the
picture in motion, be sure to try this yourself.
Figure 12.22 Normal Density Example for Handle
To avoid errors, be sure to set the initial values of the handle’s coordinates, as in the first line of this example.
If you want to use some function of a handle’s coordinates, such as in the normal density example, you
should adjust the arguments for Handle. Otherwise, the handle marker would run away from the mouse.
For example:
YFunction(a*x^b);
handle(a,b,a=2*x,b=y)
Suppose you drag the marker from its initial location to (3,4). The parameter a is set to 6 and b to 4, the
graph is redrawn as Y = 6x 4 , and the handle is now drawn at (6,4), several units away from the mouse. To
compensate, you would adjust the first argument to handle, for example.
handle(a/2,b,a=2*x;b=y)
To generalize, suppose you define the Handle parameters as functions of the handle’s (x, y) coordinates. For
example, a=f(x);b=g(y). If f(x)=x and g(y)=y, then you would specify simply a,b as the first two
arguments. If not, you would solve a = f(x) for x and solve b = g(y) for y to get the appropriate arguments.