SEQUENCE_STREAK_DISPLAY
Display a "Streak Plot" of a Sequence

SEQUENCE_STREAK_DISPLAY, a MATLAB program which displays a "streak plot" of a numeric sequence.

The idea is very simple. We can think of a sequence Y as the pairs of values (I,Y(I)). We can then plot this sequence in the usual way. To make a "streak plot", however, we now extend a horizontal ray from each plotted point all the way to the right.

Such a plot can be useful for examing the van der Corput sequence, for instance, which "fills in" the unit interval in a regular way. Looking at the streak plot, you can see the gaps between values shrinking as you move to the right.

Another possible use for such plots is for sequences with one, or better yet several, accumulation points. In that case, you will see the streak lines clustering together as you proceed.

Usage:

sequence_streak_display ( 'filename', 'direction' )

• 'filename' is a quoted string or string variable containing the name of the file with the data;
• 'direction' is a quoted character or character variable with the value 'R', 'L', 'U' or 'D' depending on whether the sequence is to be shown horizontally ('R' or 'L') or vertically ('U' or 'D'), with the streak starting ('R' or 'U') or ending ('L' or 'D') at the sequence value.

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Languages:

SEQUENCE_STREAK_DISPLAY is available in a MATLAB version.

Related Data and Programs:

CIRCLE_GRID_DISPLAY, a MATLAB program which reads a matrix of integers, and draws a corresponding grid of circles filled with color.

COLLATZ, a MATLAB library which generates the Collatz sequence, which can be displayed by SEQUENCE_STREAK_DISPLAY.

GRIDLINES, a MATLAB library which gives the user more control over drawing gridlines on a graph than the builtin "grid on" command.

NESTED_SEQUENCE_DISPLAY, a MATLAB program which reads a set of sequences, plots them as horizontal lines of data, and connects sequence entries that are equal.

PLY_DISPLAY, a MATLAB program which displays an image of a 3D graphics file in PLY format;

sequence_streak_display_test

VAN_DER_CORPUT, a MATLAB library which generates the van der Corput sequence, which can be displayed by SEQUENCE_STREAK_DISPLAY.

Source Code:

• sequence_streak_display.m, reads a file of sequence values and creates a streak plot;
• timestamp.m, prints the YMDHMS date as a timestamp;