Recent content by Fred_a

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    How to calculate conditional density

    Hi, If we have a bivariate Gaussian dist as N(m, a). m=mean and a=variance. how can we find f(x|y) in terms of m and a? Thanks
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    Can you give me some references?

    I need the derivation of the parameters of distributions including: Gumbel, Weibal, Lognormal and Gamma with both method of moments and maximum likelihood methods. Can you introduce me some references for the full derivation? If you are referencing book I appreciate if you can do more than one...
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    different test for normality

    Hi, Can anybody give a brief description for different non-parametric tests of distributions (like normality)? what are differences between Kolmogorov-Smirnov, Lilifor and Shapiro-Walk tests for normality?
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    Alternative nonparametric test for chi-square test for independence

    Hello, suppose we have a table like this: and we want to know if wining or loosing depends on sex (male or female) apart from chi-square test for Independence, which non-parametric tests we can use? Thanks
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    Trend Stationarity vs. Level Stationarity

    Can s.b. explains the difference between Trend Stationarity and Level Stationarity?
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    How to calculate ARIMA(1,0,1)

    Hello, I want to forecast the 101th data of a time series and my data is as follow 99) 0.96 100) -0.2495 101) ? and my model Coefficients: ar1 ma1 intercept 0.6769 -0.4255 0.0019 s.e. 0.1210 0.1505 0.0876 By using R I know answer is 0.084036 but I...
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    Assumptions for an ARIMA(p, d, q) model (Box-Jenkins)

    I have a data set which is stationary but the histogram looks like a logaritmic distribution. Is this a problem? Is normality an assumption to use this model? what should I do? Thanks
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    charectristics of a data set for Standardizing

    Hi, for standardizing a data set or (x-mean)/variance we are assuming a Gaussian distribution for the data. What should we do to know that this assumption is valid for our data? should we for example draw the QQ-Plot? Thanks
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    Assumption of variables for Factor Analysis

    Hi, In wikipedia page of Factor Analysis it states:Suppose we have a set of p observable random variables. Does it mean that we can use this method only for data which are random variables?! http://en.wikipedia.org/wiki/Factor_analysis
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    What is the difference between a white noise process and a random process?

    Hi, What is the difference between a white noise process and a random process? Thank you
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    p value interpretation in Mann-Kendall test

    Hi, I am performing a Mann-Kendall test on a set of a data. and I got a p value of 0.15 so it means the null hypothesis of NO TREND is not rejected. Does it mean that it it accepted and there is no trend in my data or it should be 0.95 to say that there is no trend in my data? how this p value...
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    Confused about Correlation Terms

    Hi, I am confused about different correlation terms. Can you help me? Difference between Cross correlation, Serial Correlation and Seasonality Thanks
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    the difference between non-stationary data and random data?

    what are the the difference between non-stationary data and random data? If we detrend a stationary data and make it non-stationary what will happen, will it be random?
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    Convert to Reandom Variables- Time Series Analysis

    Hi, I have a set of water quality data that are not random but I want use them in a Copula model so I should have random variables (I know it can done with time series analysis). Can anybody help me in finding a journal paper or book that I can use as a guide. Thank you
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    Parzen Window

    Hello, Is there any newer or better method (instead of Parzen) for estimating a probability density function from a set of data? for example can we use Copula? Thanks