MATLAB Plot

Discussion in 'Programmer's Corner' started by dbossnirvana, Jan 8, 2011.

  1. dbossnirvana

    Thread Starter New Member

    Dec 22, 2010
    4
    0
    I'm trying to plot the inverse Laplace transform of


    Code ( (Unknown Language)):
    1.  
    2. >>syms s
    3. >>Ys3 = (80000*s^2 + 400000*s)/(s^5 + 30*s^4 + 395300*s^3 + 11850000*s^2 + 202500000*s);
    So I take this function and calculate its inverse laplace transform and I get this,
    Code ( (Unknown Language)):
    1.  
    2. >>yt3 = ilaplace(Ys3);
    3. >>yt3 = sum((400000*exp(r3*t) + 80000*r3*exp(r3*t))/(4*r3^3 + 90*r3^2 + 790600*r3 + 11850000), r3 in RootOf(s3^4 + 30*s3^3 + 395300*s3^2 + 11850000*s3 + 202500000, s3))
    4.  
    Needless to say, I'm stumped as to how I can graph this using the plot function. Because I don't know how to express the above result into something I can plot. Thus my dilemma.

    Anyone knows how to get around this?

    Thanks.
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,392
    497
    I would do this:
    yt3=ilaplace(Ys3);
    t=0:0.001:2;
    plot(t, yt3);
     
  3. dbossnirvana

    Thread Starter New Member

    Dec 22, 2010
    4
    0
    It's what I tried, but ilaplace(Ys3) outputs a symbolic expression. I'm not sure how MATLAB can recognize the "sum((400000...)) r3 in RootOf(...)" as a vectorized solution.

    Has me really stumped.
     
  4. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,392
    497
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