Overview
First Applet
First Application
First Graph
First Project
Models
Loader
Keyframe
Linear Alg
Torus Knot
Picking
Camera Events
Color Selector
Slider
Ruler
Vector Field
Polygon Sets
Scalar Field
ODE
Root Finder
Parm Curve
Parm Surface
L-System
Texture
Refinement
4D Transform
Size Vertex
Size Polygon
Size Edge

## Type and Solve ODE's

Pick and drag new initial point in the viewer window. This modifies the
initial `x`

and `y`

values. Initial values of higher
derivative of `y`

can be modified inside the text field ```
Initial y
```

.

Type a new differential equation. Whenever you type in a text field press `
enter`
to submit your changes. Use keyboard key `i`

to switch back to mode
allowing picking of initial values:

i | pick initial `x` and `y`
values |

The integrator is a fourth-order Runge-Kutta method with constant step size.

### Controls in ODE project panel:

ODE text field | Type a new ordinary differential equation. Higher
derivatives of `y` must be denoted `dy, d2y` or ```
d3y
``` . In this text field you can use all mathematical functions
shown in Expressions.html. |

Text field "Order" | Defines the order (highest derivative of `y` )
of the differential equation |

Slider "Step Size" | Discretization for `x` -values |

Slider "Length" | Length of the `x` -interval to evaluate the
differential equation. |

Slider "Initial x" | Minimum value for `x` -interval |

Text fields "Initial y" | The first text field shows the initial `y` -value,
the second text field shows the initial value of the first derivative of ```
y
``` , if "Order" is greater than 2, further text fields for the higher
derivatives are displayed. |

View source code:

PaExprOde.java of applet,

PjExprOde.java of project,

PjExprOde_IP.java of project panel.