How do I deal with this function handel error?

my height file:

function h = height(t)

h =  @(t) ((-9.8).*(2.^(-1))).*(t.^2) + 125.*t + 500;

h(h<0) = 0;
if h(t) <0
   then h=0
end
   end

My main file:

clear all; clc;
t = 0:.01:35;
h = height(t)

%Part C (maxima)
[xpsudeomax,ymax] = max(h(t));   
xrealmax = t(ymax);
maxfunction = [xrealmax,ymax];
%fminbnd function
[xmax2,ymaxpsudeo]= fminbnd(@(t) (-1.*h(t)),0,30);
yrealmax = -1.*ymaxpsudeo;
format long g
fminbndmax = [xmax2,yrealmax] ;
%Part D 
[xzero,ypsuedozero]= fzero(@(t) h(t),20);
yrealzero = round(ypsuedozero);
ZERO = [xzero,yrealzero];

%Part B (height vs time) 
figure;
plot(t,h(t),'blue',xmax2,yrealmax,'go','LineWidth',2);
hold on;
plot(xzero,yrealzero,'r.','MarkerSize',20);
title('Rocket Trajectory');
ylabel('altitude [m]');
xlabel('time [sec]');
axis([0 35 0 1500]);
legend('height','max','ground','location','ne')

I keep getting the

"Undefined operator '<' for input arguments of type 'function_handle'.
Error in height (line 7)
h(h<0) = 0;"

How would I resolve this? I got everything on my graph right, but I can't get the flat,horizontal line to appear at the very end.

[per isakson]

See

• if, elseif, else, Execute statements if condition is true
• Anonymous Functions

[Ruten9]

How would I go about that for this problem? I'm very lost.

[Walter Roberson]

Duplicates http://uk.mathworks.com/matlabcentral/answers/250952-how-can-i-make-a-flat-horizontal-line-appear-in-matlab-when-my-values-are-less-than-zero

Answer 1

[Gareth Thomas]

Try to remove: h(h<0) = 0;

From your height function. This will help you.

[Ruten9]

My hw says that it should be there. I'm not sure why though.

[Walter Roberson]

Then either your "hw" is wrong or you have misinterpreted your "hw" or you have implemented in a way that you are not intended to use.