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Conditional statement problem in ode Matlab

  1. Oct 14, 2008 #1
    I am new in matlab and recently, I have tried coding in matlab. So far, I have been getting error msg

    "Warning: Failure at t=2.859413e+002. Unable to meet integration tolerances without reducing the step size below the smallest value allowed (1.015868e-012) at time t."

    I have referred back to my codes and realized that the problems occurs due to the conditional statement. To cut the story short, the ode doesn't seem to want to read the if, else-if statement in my codes.


    if yY(1)<=Y(1)<yY(2)
    hY = -0.0014*(Y(1)-yY(1))^3+ 0.0200*(Y(1)-yY(1))^2+ 0.8515*(Y(1)-yY(1));
    elseif yY(2)<=Y(1)<yY(3)
    hY = -0.0014*(Y(1)-yY(2))^3+ 0.0151*(Y(1)-yY(2))^2+ 0.8935*(Y(1)-yY(2))+ 1.0431;
    elseif yY(3)<=Y(1)<yY(4)
    hY = -0.0012*(Y(1)-yY(3))^3+ 0.0088*(Y(1)-yY(3))^2+ 0.9306*(Y(1)-yY(3))+ 2.4600;
    hY = 1.0000*(Y(1)-yY(19))+ 510.8083;

    It only wants to read the first highlighted piece of the code.

    Anyone help please!!!
  2. jcsd
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