The easiest way to control Pisces is through its graphical user interface. Upon first starting Pisces, you are presented with its

**File Menu**- These options control the saving and loading of data, and the quitting of Pisces.
**Output Menu**- These options control where Pisces sends data.
- View Window: Open a new two-dimensional canvas window and send data to it. This option is available to every user through the Tcl/Tk toolkit.
- Geomview: Send data to a Geomview session (invoking Geomview if necessary). This option is only available for users with UNIX workstations (or running linux on a PC) who have installed Geomview.
- Postscript File: Send data to a postscript file, in preparation for sending the file to a postscript-compatible printer.
- File: Send data to an ascii file in Geomview format.
- Standard Output: Send data directly to a the standard output in Geomview format.
- Erase All Graphics: Delete all objects from the graphics buffer.

**Algorithm Menu**- Which algorithm should Pisces use to compute a level set?
- Adaptive Grid Algorithm: Computes a curve in the plane.
- Box Algorithm: Computes a curve in the plane or a surface in 3-space.
- Geisow's Algorithm: Computes
an
*algebraic*curve in the plane. That is, the model must be a polynomial function of two variables. - Simple Algorithm: Computes a curve in the plane.
- Predictor-Corrector Algorithm: Computes a curve in arbitrary dimensions.
- Recursive Surface Algorithm: Computes an implicitly-defined surface in 3-space.
- Two-Parameter Continuation Algorithm: Computes an implicitly-defined surface in arbitrary dimensions.

**Settings Menu**- These options control parameters that determine how Pisces computes and displays
implicitly-defined curves and surfaces.
- Model: Control the domain variables, the parameters, and the range variables for the currently selected model.
- Output: Control the way that Pisces displays data.
- Jacobian: Set parameters that determine how Pisces computes derivatives and invokes Newton's method.
- Derived Model: From a single coded model, the user may derive new models and compute the level sets of these functions.
- Geomview: If Geomview is being used to view level sets, the user may decide which coordinates to send to Geomview.

**Utilities Menu**- These options are primarily self-contained scripts or short modules
that interact with the rest of Pisces to compute special features
of implicitly-defined object.
- Animate: Compute level sets for a one-parameter family of functions as a single parameter is linearly varied.
- Parametric Animate: Compute level sets for a family of functions with two parameters. The user may select an arbitrary path through parameter space.

**Model**- This menu contains a list of
all of the models which are
currently compiled into Pisces.
A
**model**is Pisces' name for the current function whose level set we want to determine.

Comments to: pisces@geom.umn.edu

Last modified: Tue Jun 4 16:30:00 1996

Copyright © 1995 by The Geometry Center, all rights reserved.