LS

Creates random loop sequences for image and graphics frames.

Formats

LS frame1 frame2 frame3 . . framen [keyword]
LS G frame1 frame2 frame3 . . framen [keyword]
LS O frame1 frame2 frame3 . . framen [keyword]

Parameters

frame1 . . n

frame numbers to include in the loop; see the Remarks

G

sets the graphics frame loop sequence; valid only in sessions with independent graphics

O

sets the opposite frame loop sequence

Keyword

Update=

Y

automatically rotates the loop's frame sequence each time a new image is displayed with the IMGDISP command, moving the new image to position one of the loop

 

N

does not rotate the frame sequence (default)

Remarks

For a sequential range of frames, use the format frame-frame Binc. frame-frame specifies the beginning and ending frames, and inc is the increment (the dash means "to" and the B means "by"). The default increment is 1. For example, LS 1-5 sets the loop sequence to 1, 2, 3, 4, 5; LS 1-5B2 sets the loop sequence to 1, 3, 5; LS 5-1B-2 sets the loop sequence to 5, 3, 1. You can also mix formats; LS 1 3 7-19B3 25 sets the loop sequence to 1, 3, 7, 10, 13, 16, 19, 25.

When you set the frame loop, the opposite frame loop is automatically set in the following manner. If frame n is less than or equal to (max frames /2), it corresponds to the opposite frame n+(max frames /2). If frame n is greater than (max frames /2), it corresponds to the opposite frame n-(max frames /2).

To override the opposite frame loop default, use the LS O command.

See Also

Use commands A, B, and L to advance, back up, and loop through the frame sequence. See Chapter 2, Introduction, for more information about the loop control system.

Examples

LS

This entry lists the current loop sequences.

LS 1 4 2 5

This entry sets the loop sequence in the order 1, 4, 2, 5.

LS 1-16

This entry sets the loop sequence to frames 1 through 16.

LS 1 16

This entry sets the loop sequence to frames 1 and 16 only.

LS 1 3 7-19B2 23

This entry sets the loop sequence to frames 1, 3, 7, 9, 11, 13, 15, 17, 19, 23.

LS O 1-4 8 9 3-1

This entry sets the opposite loop sequence to frames 1, 2, 3, 4, 8, 9, 3, 2, 1.

LS G 1-5 5-1

For a McIDAS-X session with independent graphics, this entry sets the graphics frame loop sequence to frames 1 to 5, then 5 to 1.