4.2.3. Spin Plot

This plot provides an animated 3D visualisation of data. Three variables must be selected (one for each axis) by clicking on [X axis], [Y axis] and [Z axis] from the Variable Selection Dialogue. The program then draws a 3D scatter diagram. Optionally, a factor (categorical) variable can be selected by clicking on [Factor], to plot different subgroups in different colours.

Interactive Data Points: When the graph is still in Graphics Editor (i.e. before it is sent to Excel or Word), the data points plotted by this procedure are linked with the data in data matrix (see 2.3.2.3. Interactive Data Points). Move the mouse pointer over a data point and press down the right mouse button. A tooltip-like information panel will be displayed about that point until you release the right mouse button. If you are running UNISTAT in Stand-Alone Mode, the row of Data Processor containing this point will also be highlighted. If the delete key is pressed while highlighting a point, this point will be excluded from the plot and the graph will be redrawn. In Stand-Alone Mode, it is also possible to select a row of the spreadsheet to highlight the points on the graph which belong to this row.

Missing Values: Any x-y-z triplets with at least one missing value are treated as missing.

Unequal Column Lengths: Columns with different lengths can be selected for X, Y and Z axes. Any point with at least one no data value will be considered as missing.

On entry, the view point will be in positive X direction, and all axes will be labelled with their Column Labels (if any). The spin buttons provided at the top of graph can be used to rotate the scatter diagram in six directions. The points nearer to the view point will be larger.

The buttons available on the graph have the following tasks:

Pitch: This rotates the points along the imaginary horizontal axis which lies across the screen.

Roll: This rotates the points along the imaginary axis which passes through the viewpoint.

Yaw: This rotates the points along the imaginary vertical axis which lies on the screen.

Zoom: This moves the view point closer to or further away from the origin.

Step 10º: By default, the rotation is in steps of 10 degrees, which can be increased or decreased by clicking on these buttons.

Also, the menu bar will provide access to the following further options:

Axes: Uncheck this to remove axes from the plot.

Centre: Uncheck this to move the origin of the graph to (0, 0, 0) in data units. When checked, the origin will be at the centre of all points.

Shake: This shakes the plot slightly from one side to another. After the shake has finished the plot will be in the same position as it began.

Cycle: When this option is selected nothing will happen immediately. However, when one of Pitch, Roll or Yaw buttons is clicked once subsequently, the plot will be rotated a full 360 degree cycle.

Colours: Background and foreground colours can be selected independently.