MATLAB: How to define a variable I just made with an IF statement

errorvariable

>> if x1 <= 0
x2 = x1./2
elseif x1 >= 0
x2 >= x1.*2
end
x3 = sqrt(y.^2 + x2.^2);
figure(1)
plot(t,x3)
Undefined function or variable 'x2'

Best Answer

It's a typo in the 4th line, remove the > and use
x2 = x1.*2
Note that if x1 is not <= 0, it must be > 0 , so you there is no need to test for >=0 in the elseif clause. So you can simply use else:
if x1 <= 0
  x2 = x1./2
else
  x2 = x1.*2
end
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