loop in a loop

i'm trying to make loop in a loop so for each index of alpha(the main loop) will path thru the all loop on v_0(the secondary loop) and store the wanted data on new vector. can someone tell me what wrong with my code

v_0=[3:0.1:20];
for i=1:size(alpha)
      for j=1:size(v_0)
          t=(5/49)*(v_0(j)*sin(a(i))+sqrt(v(j)^2*(sin(a(i)))^2-98/5));
          x=v_0(j)*cos(a(i))*t;
          v=zeros(size(alpha));
          if x>7.15 || x<6.85
          v(i)=1;
          else
          v(i)=0;
          end
      end
     end

Answer 1

[Andrei Bobrov]

v_0=(3:0.1:20);
m = numel(alpha);
n = numel(v_0);
v = zeros(m,n);
for ii=1:m
     for jj=1:n
         t=(5/49)*(v_0(jj)*sin(a(ii))+sqrt(v_0(jj)^2*(sin(a(ii)))^2-98/5));
         x=v_0(jj)*cos(a(ii))*t;
         if x>7.15 || x<6.85
             v(ii,jj)=1;
         end
    end
end

without loop for..end

MATLAB R2016b and later

a = a(:);
v_0 = v_0(:)';
t = v_0.*sin(a);
x = 5/49*v_0.*cos(a).*(t+sqrt(t.^2-98/5));
v = x > 7.15 || x < 6.85;

MATLAB R2016a and earlier

a = a(:);
v_0 = v_0(:)';
t = sin(a)*v_0;
x = 5/49*bsxfun(@times,cos(a)*v_0,(t+sqrt(t.^2-98/5)));
v = x > 7.15 || x < 6.85;

[avner yakov]

thanks allot

[Andrei Bobrov]

Hello Avner! Please accept this answer if it helped solve your problem.