I am trying to write some equations in the plot in MATLAB but, i am getting error and it's not working.

I am trying interpret equations using Latex. Here's my code and the figure attached.

   z= 0:0.01:6
  q=0.5*erfc(z./sqrt(2))
  u=(1./((sqrt(2*pi)).*z)).*exp((-z.*z)./2)
  semilogy(z,q,'color','k','LineWidth',2); 
  hold on;
  semilogy(z,u,'--'); 
  axis([0,6,10^(-8),1])
  xlabel('z \rightarrow ' );
  ylabel('Overbound approximation not applicable for small z');
  title('The function Q(z) and an overbound')
  str=strcat(' Q(z) \downarrow')
  str1= strcat('downarrow','$${{\frac{(1)}{\sqrt{2\pi}}{{\frac{\exp{(-z)^2}}(2)}$$')
  text(65,85,str);
  text(1,0.6,str1,'Interpreter','Latex','FontSize',14);

Here is my error: str =

 Q(z) \downarrow

str1 =

downarrow$${{\frac{(1)}{\sqrt{2\pi}}{{\frac{\exp{(-z)^2}}(2)}$$

Warning: Unable to interpret LaTeX string "downarrow$${{\frac{(1)}{\sqrt{2\pi}}{{\frac{\exp{(-z)^2}}(2)}$$" >>

Attached is the picture of the plot. i.e how it should look like.

Answer 1

[Walter Roberson]

You are missing several } in str1

And remember the \ before the downarrow