Subscript indices error when plotting

I am having an issue with a for loop plot. The error is returned on the line that says "plot(x,y)" on the code which follows. It states "Subscript indices must either be real positive integers or logicals." Also, if there is any way to label the plots in a legend as they are created that would be great. Thanks in advance for any help.

 for N=30:10:50
 g=9.81;tau = 0.0076;
 tmin = 0; tmax = 10;
 v0=50*sin(deg2rad(N));y0=0;
 t=linspace(tmin,tmax, 1000);
 dt=t(2)-t(1);
 a= zeros(1,numel(t));
 v= zeros(1,numel(t));
 y= zeros(1,numel(t));
 v(1)=v0;
 y(1)=y0;
 for i=2:1000
     a(i-1)= -g+(tau*abs(v(i-1))*v(i-1)); 
     v(i)= v(i-1)+a(i-1)*dt;
     y(i)= y(i-1)+v(i-1)*dt+(1/2)*a(i-1)*dt^2;
 end
 vx0=50*cos(deg2rad(N));x0=0;
 ax= zeros(1,numel(t));
 vx= zeros(1,numel(t));
 x= zeros(1,numel(t));
 vx(1)=vx0;
 x(1)=x0;
 for i=2:1000
     ax(i-1)= -tau*(vx(i-1))^2; 
     vx(i)= vx(i-1)+ax(i-1)*dt;
     x(i)= x(i-1)+vx(i-1)*dt+(1/2)*ax(i-1)*dt^2;
 end
 plot(x,y);
 ylim([0,65]);
 end

Answer 1

[Walter Roberson]

In some code not shown here, you accidentally assigned a value to a variable named plot

[Jay]

Thanks. I tried to alter the above code to generate my legend. It gave me an error, so I changed it back to the above code and tried to run it again, but it continued to give me the same error. I thought that I might have deleted something important, but I even cancelled all changes and opened the original document above and it still gave me the error. I opened it on another computer and it worked. This is strange.

[Stephen23]

"This is strange."

Not at all. You created a variable named plot.

[Jay]

I was under the impression that in livescript, every time I click "run all" it generates new variables. If I changed the code to the above script and clicked "run all," would it not delete the old variable and treat it as a plot? This is just for future reference.

[Walter Roberson]

No, anything that is in your base workspace remains in your base workspace, and any variables you assign in the live script get assigned in the base workspace. Live scripts do not have their own workspace.

[Jay]

Understood. Thank you. You have been very helpful.