Hold Off Not Working in For Loop Dynamic 3D Plotting

Hello I have been struggling with this for some time today. Although at some point in time this was working fine, I am now unable to make my dynamic plot without the previous instances of the plot being stored. I am using "hold off"; however, I am unable to fix this.

Here is the part of my code that graphs my hand motion model:

finger_r = 1.5;
thumb_r = 1.6;
n = 20;
cyl_color = 'yellow';
closed = 1;
lines = 0;

for j = 1:Size
    %Coordinate Set
    %Pinky 1
    xyz_begin_1_1 = [1.5 0 0];

    xyz_end_1_1 = [x_1_1(j) y_1_1(j) z_1_1(j)] + xyz_begin_1_1;

    %Pinky 2
    xyz_begin_2_1 = xyz_end_1_1;

    xyz_end_2_1 = [x_2_1(j) y_2_1(j) z_2_1(j)] + xyz_begin_2_1;

    %Ring 1
    xyz_begin_1_2 = [5 0 0];

    xyz_end_1_2 = [x_1_2(j) y_1_2(j) z_1_2(j)] + xyz_begin_1_2;

    %Ring 2
    xyz_begin_2_2 = xyz_end_1_2;

    xyz_end_2_2 = [x_2_2(j) y_2_2(j) z_2_2(j)] + xyz_begin_2_2;

    %Middle 1
    xyz_begin_1_3 = [8.5 0 0];

    xyz_end_1_3 = [x_1_3(j) y_1_3(j) z_1_3(j)] + xyz_begin_1_3;

    %Middle 2
    xyz_begin_2_3 = xyz_end_1_3;

    xyz_end_2_3 = [x_2_3(j) y_2_3(j) z_2_3(j)] + xyz_begin_2_3;

    %Index 1
    xyz_begin_1_4 = [13 0 0];

    xyz_end_1_4 = [x_1_4(j) y_1_4(j) z_1_4(j)] + xyz_begin_1_4;

    %Index 2
    xyz_begin_2_4 = xyz_end_1_4;

    xyz_end_2_4 = [x_2_4(j) y_2_4(j) z_2_4(j)] + xyz_begin_2_4;

    %Thumb 1
    xyz_begin_1_5 = [15 -10 0];

    xyz_end_1_5 = [x_1_5(j) y_1_5(j) z_1_5(j)] + xyz_begin_1_5;

    %Thumb 2
    xyz_begin_2_5 = xyz_end_1_5;

    xyz_end_2_5 = [x_2_5(j) y_2_5(j) z_2_5(j)] + xyz_begin_2_5;

    %Plot Rectangle Hand
    Cylinder([7.5 0 -7.5],[7.5 -10 -7.5],7.5,n,cyl_color,closed,lines)

    %Plotting Fingers -----------------------------------------------------
    %Pinky
    Cylinder(xyz_begin_1_1,xyz_end_1_1,finger_r,n,cyl_color,closed,lines)
    Cylinder(xyz_begin_2_1,xyz_end_2_1,finger_r,n,cyl_color,closed,lines)

    %Ring
    Cylinder(xyz_begin_1_2,xyz_end_1_2,finger_r,n,cyl_color,closed,lines)
    Cylinder(xyz_begin_2_2,xyz_end_2_2,finger_r,n,cyl_color,closed,lines)

    %Middle
    Cylinder(xyz_begin_1_3,xyz_end_1_3,finger_r,n,cyl_color,closed,lines)
    Cylinder(xyz_begin_2_3,xyz_end_2_3,finger_r,n,cyl_color,closed,lines)

    %Index
    Cylinder(xyz_begin_1_4,xyz_end_1_4,finger_r,n,cyl_color,closed,lines)
    Cylinder(xyz_begin_2_4,xyz_end_2_4,finger_r,n,cyl_color,closed,lines)

    %Thumb
    Cylinder(xyz_begin_1_5,xyz_end_1_5,thumb_r,n,cyl_color,closed,lines)
    Cylinder(xyz_begin_2_5,xyz_end_2_5,thumb_r,n,cyl_color,closed,lines)

    axis([-20 20 -20 20 -20 20])
    drawnow
    hold off
end

All of the instances of my dynamic plot are staying on the figure. I want the graph to clear the previous instance every time it graphs a new iteration of my for loop.

Answer 1

[Walter Roberson]

"hold off" only works if the current axes happens to be the same as the axes the plots are drawn in. As we do not know anything about the Cylinder routine we cannot say what it is doing.

[Mike Garrity]

In addition, hold is about functions that make "charts". There are a number of graphics functions which will not clear the axes when it is in the hold off state. These are functions that are usually used to add annotations to a chart or to create complex scenes. Examples include:

• text
• line
• patch
• ...

If you're using these instead of the charting functions, then you need to manage the contents of the axes yourself. You can either:

• Keep the handles these functions return, and call delete on them
• Use cla to clear everything in the axes