# User Portlet

Discussions |
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Thank you very much for your help again! Yes, I do understand your point and it is quite well making sense. I have downloaded your file, copied and pasted into my Mathematica 7 notepad and executed. But instead, the status is in the running mode... |

Hi. May I ask whether Mathematica can import real world raw data like asset prices of the firm to compute the covariance of the asset prices, or the volatility of the portfolio of the asset prices? In addition, is there a way that I can assign the... |

Thank you! It seems like the FindSequenceFunctin works with the list of numbers, not with the one type of long variable.; The type of term that I want to abbreviate is like: (Sqrt[3] *F* (u[1, 0] - 2 u[1, 1] + u[1, 2] + 2 (u[2, 0] - 2 u[2, 1] +... |

Thank you Bill! You are quite a huge helper! Hope you have successes for your future careers as well! Thanks to Nasser as well! :) To be honest, my final step towards the problem will be having the simplest expression of the result that I can... |

Thanks again! So, if I want to disregard the imaginary number part for the covariance matrix by using the following code: cv = Covariance[Table[u[i, t] - u[i, t - 1], {t, 1, 3}, {i, 1, 2}]]; m = Simplify[cv, Element[u[_, _], Reals]] -> Then, is... |

Like something that includes sigma and etc which abbreviates the whole equation by considering the patterns of the variables. |

Hi, I am trying to produce the most abbreviated expression of the formulas inside the resulting matrix of the following code: [mcode]as = Variance[Table[u[i, t] - u[i, t - 1], {t, 1, 3}, {i, 1, 2}]]; MatrixForm[Simplify[as, Element[u[_, _], Reals]]];... |

Thank you very much! I eventually resoved the problem. Thanks a lot! |

Hi, I am using the following function:: [mcode]Refine[D[(Sum[((u[k, t] - u[k, t - 1])^2)/T, {k, 1, 10}, {t, 1, 5}] + 2*(Sum[Sum[(u[i, t] - u[i, t - 1])*(u[j, t] - u[j, t - 1]), {i, 1, 9}, {t, 1, 5}], {j, 2, 10}]/T)*F)^(1/2), u[1,... |