How to adjust arrowheads in streamslice?

I would like to use streamslice but the arrowheads are way too big so you can't see them anymore (see first picture). At first I was not sure if really the arrowheads were the problem but when I remove them the plot looks normal (see second picture). As I want arrowheads in the plot - does anyone know how I can solve the problem or adjust the size of the arrowheads?

Thanks in advance!

Here is my code:

syms a r
r1 = 5*10^(-11);        
r2 = 0.01;              
r3 = 20;               
r4 = 0.1;               
r5 = 1.386;       
r8 = 0.0723;            
r10 = 0.5;              
r11 = 0.0001;           
n_alpha = 1*10^(3);     
r6 = 0.045;

lo_a = 0;
up_a = 10000;
lo_r = 0;
up_r = 0.8;
[A,R] = meshgrid(lo_a:100:up_a,lo_r:0.08:up_r);

a_dot = -r6.*A + r4*n_alpha*r10*r11./(r10*r11+r1*r2*A.^2.*R.^2) + r3*n_alpha*r1*r2*A.^2.*R.^2./(r10*r11+r1*r2*A.^2.*R.^2);
r_dot = -r5.*R + r4*r10*r11./(r10*r11+r1*r2*A.^2.*R.^2) + r3*r1*r2*A.^2.*R.^2./(r10*r11+r1*r2*A.^2.*R.^2);

streamslice(A,R,a_dot,r_dot,2);
xlabel('a')
ylabel('r')

xlim([lo_a up_a])
ylim([lo_r up_r])

Answer 1

[Hannah Diethard]

For anyone interested: I solved to problem by rescaling r

syms a r
r1 = 5*10^(-11);        
r2 = 0.01;              
r3 = 20;               
r4 = 0.1;               
r5 = 1.386;       
r8 = 0.0723;            
r10 = 0.5;              
r11 = 0.0001;           
n_alpha = 1*10^(3);     
r6 = 0.045;

lo_a = 0;
up_a = 10000;
lo_r = 0;
up_r = 1;
scale = 10000;
[A,R] = meshgrid(lo_a:100:up_a,lo_r:0.1:up_r);

a_dot = -r6.*A + r4*n_alpha*r10*r11./(r10*r11+r1*r2*A.^2.*R.^2) + r3*n_alpha*r1*r2*A.^2.*R.^2./(r10*r11+r1*r2*A.^2.*R.^2);
r_dot = -r5.*R + r4*r10*r11./(r10*r11+r1*r2*A.^2.*R.^2) + r3*r1*r2*A.^2.*R.^2./(r10*r11+r1*r2*A.^2.*R.^2);

streamslice(A,R*scale,a_dot,r_dot*scale,2);
xlabel('a')
ylabel('r')
yticks([0*scale 0.5*scale 1*scale])
yticklabels(num2str(yticks'/scale))
xlim([lo_a up_a])
ylim([lo_r*scale up_r*scale])

Answer 2

[Gowthami]

Hi,

There is no direct way to modify the arrowhead separately from the lines themselves in "streamslice".

As a workaround, you can parse through the individual lines that make up the arrowheads in the stream slice plot by checking for lines that only have 3 vertices and then modify the line properties of those line groups so that the arrowhead properties are modified. For example in the following code, I am modifying the line width of arrowheads to 0.05.

load fileName;
s = streamslice(x,y,z,u,v,w,[],[],5);
for i = 1:length(s) 
    % If line is part of arrowhead
    if length(s(i).MarkerIndices) == 3
        s(i).LineWidth = 0.05;
    end
end

You can modify other arrowhead properties too by looking at a list of all available properties:

https://www.mathworks.com/help/matlab/ref/matlab.graphics.primitive.line-properties.html

[Hannah Diethard]

Hi,

thanks for your answer! Unfortunately, this changes only how thick or thin the arrowheads are but not how long which is the problem I think ...