# How to change angle of arrow in Plot

**URL:** <https://discourse.julialang.org/t/how-to-change-angle-of-arrow-in-plot/90781>\
**Category:** New to Julia\
**Tags:** plotting, plot\
**Created:** [November 24, 2022, 9:39pm UTC](https://discourse.julialang.org/t/how-to-change-angle-of-arrow-in-plot/90781 "2022-11-24T21:39:20Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![elliot000319](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/elliot000319/32/36789_2.png) [@elliot000319](https://discourse.julialang.org/u/elliot000319)\
**Post date:** [November 24, 2022, 9:39pm UTC](https://discourse.julialang.org/t/how-to-change-angle-of-arrow-in-plot/90781/1 "2022-11-24T21:39:20Z")

</div>

I am trying to plot the changes in body angle using arrow in plot. I set the initial body angle as 45 degrees. I want to make the blue square and the arrow turn according to the change in angle. q is the position of the robot at every frame, and ang should be the angle at that frame. Rotation in anti-clockwise direction is set as positive.  
 ![NLmpc_angle](https://global.discourse-cdn.com/julialang/original/3X/d/f/df17db1d5e9980416c61ccecbae9aa2ecd4b22a9.gif)

```julia
begin
	# The robot's starting position and velocity
	q = [1.0, 0.0]
	v = [-2.0, 2.0]
	ang = 45
	Δt = 0.1

	qs_x = []
	qs_y = []
	as_x = []
	as_y = []
	angs = []
	
	anim = @animate for i in 1:80 # This determies the number of MPC to be run
	    # Plot the current position
		# Attitude of the vehicle is not considered
	    plot([q[1]], [q[2]], marker=(:rect, 10), xlim=(-2, 2), ylim=(-2, 2))
		push!(qs_x,q[1])
		push!(qs_y,q[2])
		plot!([q[1]], [q[2]], marker=(:cross, 18, :grey))
	    
	    # Run the MPC control optimization
	    q_plan, v_plan, u_plan, ang_plan = run_mpc(q, v, ang)
	    
	    # Draw the planned future states from the MPC optimization
	    plot!(q_plan[1, :], q_plan[2, :], linewidth=5, arrow=true, c=:orange)
	    
	    # Save Acceleration & Angle Data to csv
	    u = u_plan[:, 1]
		global ang = ang_plan[1]
		push!(as_x, u[1])
		push!(as_y, u[2])
		push!(angs, ang_plan[1])
		
		# Apply the planned acceleration and simulate one step in time
	    global v += u * Δt
	    global q += v * Δt
	end
	gif(anim, "~/Downloads/NLmpc_angle.gif", fps=60)
end

```