OneStone® Pebbles

OneStone® Pebbles Contour Diagrams

The Contour Diagrams Pebble provides an unparalleled visualization of this topic. The 3D display brings this topic to life in a way a conventional 2D applet cannot; when combined with a 2D display, the concept is presented with simplicity and clarity. The slider controls the level at which the curve is drawn; both 2 and 3D displays will vary in real time in response to slider input.

The User Interface of this Pebble works a little differently from the default operation described on the Using Pebbles page. The procedure for using the Contour Diagrams Pebble is outlined below.

• Click the 'Launch...' link below to start the Contour Diagrams Pebble. The process of installing and running a Pebble for the first time is explained on the Installing Pebbles page.
• Enter an expression in the text box at upper left. This Pebble accepts all the standard math operators plus the variables X, Y, R and/or Theta. The 3D display will show a ghostly image of the surface defined by the user's expression, drawn as Z = F(...), giving context to the contour curve. The Contour Curve itself is drawn in both displays, at the level defined by the slider control.
• Drag the slider to vary the level at which the contour curve is drawn. The curves will animate in response to the motion of the slider. At the same time, the current value display will change to reflect the new value.
• Click and drag the 2D display window to shift the graphed region. Both displays update in real time as the 2D surface is dragged. Zoom controls below the modified expression display can also be used.
• Click and drag the 3D display to change the viewing angle. The colors of visual elements can be changed, as well, to improve contrast/visibility.

Before launching the Pebble you must agree to the End User License Agreement. In brief, it says you won't claim the work to be your own, you won't attempt to resell it and you won't attempt to disassemble it.