Sequencer

Category

Special

Function

Generates a sequence of integers.

Syntax

The sequencer is available in script mode and in the user interface. However, it can be data driven only in the user interface (see Chapter 10. "Data Explorer Scripting Language" in IBM Visualization Data Explorer User's Guide, and the example later in this section.)

Inputs

Name	Type	Default	Description
min	integer	1	minimum of integer sequence
max	integer	100	maximum of integer sequence
delta	integer	1	numerical interval between successive integers in the sequence

Outputs

Name	Type	Description
frame	integer	frame number

Functional Details

This module allows a user to "animate" a visualization. Through inputs to the module (outputs from other tools or values set in its configuration dialog box) the interactor can be "data driven."

If the interactor is not data-driven, its attributes are taken from its Frame Control dialog box (accessed from the ... button).

The configuration dialog box for Sequencer can be accessed by selecting the Sequencer icon in the VPE and then choosing Configuration in the Edit menu.

min  and  max	specify the minimum and maximum integer values (frame numbers) for an "animation" sequence. By default, min = 1 and max = 100.
delta	specifies the increment between integers in the output sequence. If min and max are equal, delta is ignored. By default, delta = 1.

Note: If min is specified, and either min or max change, the output value (frame) is set to the new min value and the Start and Stop values in the Frame Control dialog box are set to the new minimum and maximum, respectively.

However, if min is not specified and max is and then changes on the next execution, the output frame value becomes the current Start value as set in the Frame Control dialog box.

Script Language Example

The following example uses the Sequencer in script mode to display a series of isosurfaces. The input to the macro do_each_frame is the frame number, which is converted into an isosurface value by multiplying it by 0.05. The initialization values are set by @startframe, @endframe, and @nextframe. The sequence command invokes the macro for each step of the sequence. Finally, the play command starts the Sequencer running. For more information about using the sequencer in script mode, see Chapter 10. "Data Explorer Scripting Language" in IBM Visualization Data Explorer User's Guide.

macro do_each_frame(frame)
{
   isovalue = frame*.05;
   isosurface = Isosurface(data,isovalue);
   Display(isosurface,camera);
}
data = Import("/usr/local/dx/samples/data/cloudwater");
camera = AutoCamera(data);
@startframe = 1;
@endframe = 5;
@nextframe = @startframe;
sequence do_each_frame(@frame);
play;

Example Visual Programs

Many of the example visual programs use a sequencer, including:

ContoursAndCaption.net
GeneralImport1.net
MovingCamera.net

The following example visual program uses a data-driven Sequencer:

Imide_potential.net