@acer 

Thank you very muc, acer. Why does it work with trunc(i) in L[trunc(i)] and not just i? Isn't i supposed to be an integer here?

mapleatha

@Kitonum 

Thank you, Kitonum. Acer has told me above why the code was not working and gave me a working alternative.

Thank you, again.

mapleatha

@tomleslie 

Thank you, tomleslie. The problem was solved above by acer.

mapleatha

@acer 

This is it!!! Thanks a million, acer.

mapleatha

@acer 

Here is exactly what I am using:

F := proc(t)
plottools[line]([-2,0], [cos(t)-2, sin(t)], color=blue,thickness=3),
plottools[line]([cos(t)-2, sin(t)], [t, sin(t)], color=blue,thickness=3),
plot(sin(x), x=0..t, view=[-3..7, -5..5],thickness=3):
end proc:

plots:-animate(F,[theta],theta=0..2*Pi,background=plot([cos(t)-2,sin(t),t=0..2*Pi],thickness=3),
scaling=constrained,axes=none);

Error, (in plots/animate) plotcommand did not return a PLOT or PLOT3D object

@acer 

acer, tomleslie sent me the same exact code below. It doesn't work either in Maple 2013 or Maple 2020.
Thank you!

mapleatha

@tomleslie 

Sorry, tomleslie, I got the same response from Maple when I used your file:

Error, (in plots/animate) plotcommand did not return a PLOT or PLOT3D object

mapleatha

@acer 

Thank you, acer. When I use plot:-animate
I get

Error, (in plots/animate) plotcommand did not return a PLOT or PLOT3D object

When I erase the commas and replace them by colons or semicolons,
I do not get the two straight line segments plotted.
This is happening in Maple 2020 as well.
Please elaborate.

Thank you again.

mapleatha

@Ramakrishnan 

The degree symbol in my original message was not done with nprintf(`#mn("%a°");`, 30)), or anything like that. It was done with the ALT-key on the keyboard plus 0176 on the keypad. Here it is 30°.
Thanks again.

mapleatha

@acer 

This is just great, @acer. Once again, you solved the problem beautifully.

mapleatha

@Ramakrishnan 

Thank you Ramakrishnan. I know all that. I needed the font used for the degree number changed to Arial.

mapleatha

@acer 

It works fine, @acer, thank you. Why was the Arial font changed for the number 30 though?

mapleatha

@one man 

Thank you, but I don't want the paretnheses.

mapleatha

@Carl Love 

Thank you, Carl. Acer just gave me an answer that I can use nicely.

mapleatha

@acer 

Thank you, Acer. This would fix the problem very nicely.

mapleatha