Recent content by AcesofSpades

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    MATLAB Defining Variables in MATLAB Transfer Function?

    Please can anyone help? It is urgent!
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    MATLAB Defining Variables in MATLAB Transfer Function?

    I have the transfer function z+b/z^2-1.5*z+0.7 I want to write this to MATLAB so : syms b h=tf([1 b],[1 -1.5 0.7],1) The problem is that it returns an error of the variable b. How can I define it so that I can get an answer?
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    Variance of a function in an infinite space

    Thank you, you have been very helpful! One last question: Since t is time I want the erf(t) from 0 to inf So how the mean and the variance adjust to this? (mean is 1 and variance is 0?)
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    Variance of a function in an infinite space

    So I cannot find the variance without having the probability density function? Another thought: Can I say from the plot that mean of erf(x) is zero and variance of erf(x) is one?? http://upload.wikimedia.org/wikipedia/commons/2/2f/Error_Function.svg
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    Variance of a function in an infinite space

    Sorry, forget about the infinities in the previous post. So I want to calculate the variance with Variance= E (x^2) - [E(x)]^2 I calculate the μ=E(erf(x))=lim(L->inf)((1/L)*int(a*erf(x),0,L)) = a So then I want to calculate the E(erf(x)^2) and with the previous type I have an integral of...
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    Variance of a function in an infinite space

    I am sorry for double posting but it seems that I find a wall in my way. Could you show me the direction about the variance of the error function?
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    Variance of a function in an infinite space

    Thank you for answering! So I open the MATLAB to calculate the variance and it seems that there is not a command for the variance of a function. So I calculate the Variance= E (x^2) - [E(x)]^2 However, when I calculate the E(x^2) = int (x^2*erf^2) MATLAB returns this: Warning: Explicit...
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    Variance of a function in an infinite space

    Homework Statement It is given a function y(t)=ae(t) where e(t) is the "[URL error function [/URL] I am looking for the variance of this function in an infinite space. Since t is time, I assume that this space is defined as [0,+∞). Thus, the usual variance functions does not apply since...
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