Hi, I'm trying to find a program line which will make matlab dump numbers that don't respond to an if statement.

            if abs(z(1,end,n)-Z)<=Err
                hold on
                figure(1)
                plot(z(1,:),z(3,:))
                xlabel('x')
                ylabel('y')
                axis ([0 12000 0 10000])
            else
                %Dump, don't plot.

[Jan]

What exactly does "dump" mean?

[Christopher]

I want simply to stop it from plotting everything, i'll post the code so you can run it.

    function [ ] = lolly()
tInc = input('Input desired timestep (in seconds)');
Z = input('Input desired Landing distance (in meters)');
t(1)=0;
Ang1 = input('First angle of shooting (in degrees)');
Ang2 = input('Last angle of shooting (in degrees)');
AInc = input('Angle increment (also in degrees)');
Err = input('Acceptable Error (in meters)');
w = (Ang2-Ang1)/AInc;
IAng = linspace(Ang1,Ang2,w);
for n=1:w;
        z(:,1,n) = VelocityforAngle(IAng(n));
        i=1;
        while z(3,i,n)>=0;
            i=i+1;
            t(i)=t(i-1)+tInc;
            [z(:,i,n)] = oneStepRK(t(i-1), z(:,i-1,n), tInc);

            if abs(z(1,end,n)-Z)<=Err
                hold on
                figure(1)
                plot(z(1,:),z(3,:))
                xlabel('x')
                ylabel('y')
                axis ([0 12000 0 10000])

            else

            end

        end
end

[Walter Roberson]

You want it to stop all further plots? Or you want it to continue on with the next "n" ? Or you just don't want to plot that one line?

The code you already give will have it skip one line.

Earlier on you assign to z(:,i,n) but in that if you refer to z(1,end,n) which seems to rely upon the fact that you did not pre-allocate z and so "end" refers to the same location as "i". Why not just code as "i", z(1,i,n) and avoid the confusion ?

Why are you referring to z in 3 dimensional form as you calculate it, but in 2 dimensional form when you plot it?

Answer 1

[dpb]

If you want to abort the loop see

doc break

If you want to keep going then as Walter notes the empty ELSE clause skips effectively (of course you can just use an IF...END w/o the ELSE too)...

If it's something else, the description isn't terribly precise...