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| bio | website | |
|---|---|---|
| location | Washington, DC, USA | |
| age | 24 | |
| visits | member for | 1 year, 11 months |
| seen | May 17 at 21:00 | |
| stats | profile views | 21 |
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May 15 |
awarded | Caucus |
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Feb 24 |
comment |
Given $x(t) = u(t)$ and $h(t) = \cos(\pi t)u(t)$, how do we find the response $y(t)$? I don't see why the integral isn't $\int_{0}^{\infty}cos(\pi\tau)u(\tau)u(t-\tau)d\tau$. |
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Nov 7 |
answered | Poisson Distribution for Consecutive Figures |
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Nov 6 |
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Creating a recommender system for shoe sizing You may get better responses on Cross Validated. |
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Nov 2 |
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Solve Ax = b where b are labels instead of values @locke14 I misunderstood the question. My response was for $A$ having these entries, not $b$. |
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Nov 2 |
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Solve Ax = b where b are labels instead of values Usually with categorical variables, one category is chosen as a baseline and all others are assigned their own indicator variable in the regression. For example, if the original variable represents weight and the categories are "low", "medium" and "high", we may choose "medium" as the baseline and create two other variables named "isLow" and "isHigh". If a person has "medium" weight, isLow and isHigh will both be zero. If a person has "low" weight, isLow will be one and isHigh will be zero. If a person has "high" weight, isLow will be zero and isHigh will be one. |
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Oct 30 |
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Process for $(k+1)^3$? @wj32 Ah. That makes sense. |
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Oct 30 |
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Process for $(k+1)^3$? You don't mention the binomial theorem anywhere in your question. |
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Oct 30 |
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Process for $(k+1)^3$? Look into the binomial theorem. |
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Oct 28 |
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Puzzle on Ranks The computation is correct. This is a good way of thinking about the problem though. |
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Oct 26 |
accepted | Help Needed: Partial Derivative Identity/Chain Rule |
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Oct 26 |
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Formulas for the multivariate Gaussian function? If you convert the density function to use the actual elements of $x$ and $\Sigma$ rather than the matrix equivalents, taking derivatives will become more clear. |
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Oct 17 |
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Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$ Yes, that is correct. |
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Oct 17 |
revised |
Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$ added 186 characters in body |
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Oct 17 |
answered | Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$ |
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Oct 17 |
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Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$ I think you mean $Var(X)=E(X^2)-\mu^2$. |
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Oct 15 |
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Approximate probability mass function into normal distribution The normal distribution is characterized by its two parameters: its mean and variance. Find the mean and variance of your data ($\bar{x}$ and $s_x^2$, respectively) and plug those in to the normal density function. |
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Oct 14 |
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Matrix times its transpose equals original matrix In the case of a symmetric matrix, this property is called idempotence. |
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Oct 9 |
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Let $P(X=1)=0.6$ and $P(X=1,Y>=5)=0.2$. Find $P(X=1,Y<5)$. You're using conditional probabilities without proper notation. $P(Y\geq5|X=1)=P(X=1,Y\geq5)/P(X=1)=1/3$ and $P(Y<5|X=1)=1-P(Y\geq5|X=1)=2/3$. Then $P(X=1,Y<5)=P(Y<5|X=1)P(X=1)=2/3\times3/5=2/5$. |
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Oct 3 |
comment |
Find out the cdf, pdf, but failing with combinatorics? Think about drawing blocks from a bag without replacement. For the first pattern (red, green x 4, red), how many ways can you pull a red block first? Now you've gotten rid of a red, so how many ways can you pull a green block second? Then keep going. The probability of any individual pattern will be the ratio of the number of ways for that pattern to occur to the total number of ways for any pattern to occur. Also, think about why the cases above are not the only ones that can occur. (Hint: Why must a red block come first?) |
