Recent content by h6ss

  1. h6ss

    I Hessian of least squares estimate behaving strangely

    I believe Levenberg-Marquardt is more robust than quasi-Newton methods for computational nonlinear regression, and generally works better for ill-conditioned problems. Also, have you tried different methods for calculating the eigenvalues? Or even, for inverting your Hessian matrix? That 170,000...
  2. h6ss

    Distribution of exponential family

    Consider the random variable ##Z=Y_1+Y_2##. Therefore, you have: ## \begin{eqnarray*} \frac{\Gamma(y_1+y_2+\gamma)}{(y_1+y_2)! \ \Gamma(\gamma)} = \frac{\Gamma(z+\gamma)}{z! \ \Gamma(\gamma)} = \frac{1}{z!} \cdot \frac{1}{\Gamma(\gamma)} \cdot \Gamma(z+\gamma) \\ \end{eqnarray*}## Do you have...
  3. h6ss

    False positive rate over two tests

    Yes! A commonly used example in introductory Bayesian statistics is the rare disease example. If a disease is very rare, then your probability of really having the disease given a positive test result remains low. Suppose a disease that affects 0.1% of the population is diagnosed with 95%...
  4. h6ss

    Is it possible to know a random choice in the past?

    What's particular with ideal randomness is that it is perfectly independent of everything, in particular knowledge and time. If the first machine did randomly choose between two objects, then I would assume the second machine would rightfully predict the first machine's choice assuming it knows...
  5. h6ss

    LaTeX LaTeX Editors for Mac | Good Options for Macbook

    If you use R then I suggest you going with R-Studio, there's a LaTeX editor integrated in it (R Sweave) as long as you have the (free) TeX libraries installed on your computer. I use that because I *always* use R when I write my LaTeX, and my macbook is getting quite old so having both in the...
  6. h6ss

    Histogram to PDF Conversion: Confirm Experimental Approximation

    If you have access to the dataset, you can also use density estimation techniques like the kernel density estimation. You can find a very good explanation of this technique here: http://www.mglerner.com/blog/?p=28 I hope this helps !
  7. h6ss

    Comparing gaussian distributions with Gumbel-like distribution

    Hey! First of all, I'm curious as to what led you to think that the measurements of the analytes experiment follow a kind of Gumbel distribution. Were you given prior information stating that a Gumbel distribution was to be expected or did you just assume it followed that distribution by...
  8. h6ss

    Something I discovered doing logic

    What you "discovered" is that P&Q added to P|Q is equal to P+Q, right? Here's a short explanation of what's really happening. Using the bitwise operator "&" for the logical operator "AND" and the bitwise operator "|" for the logical operator "OR", evaluating the expression P&Q basically creates...
  9. h6ss

    Is Induction More Rigorous in First-Order Logic Than Higher-Order Logic?

    I understand what you mean. Mathematical induction is not the same as induction in the informal sense. A proof by mathematical induction ultimately reduces to mathematical axioms just as any other good rigorous proof. It is constructive in the sense that it’s a perfectly rigorous technique. But...
  10. h6ss

    Why is it that calc 3 is sometimes not required for stats?

    It does, and that's an issue that has been discussed a lot in the past years, especially in the departments of mathematics, physics and chemistry. The problem is that a lot of people start those university degrees simply because they can (the collegial requirements are fairly low; only a few...
  11. h6ss

    Why is it that calc 3 is sometimes not required for stats?

    They require a collegial orientation in either pure or health science, which gives basic classes of physics and/or chemistry, both Calculus 1 and 2 and a class of linear algebra, or a collegial orientation in social science with maths, which again gives only both Calculus and Linear Algebra...
  12. h6ss

    Why is it that calc 3 is sometimes not required for stats?

    Here in Quebec, none of the five major universities require Calculus 3 for a major in Statistics, or even in Mathematics.
  13. h6ss

    The error between two different standard deviations

    Not really, but maybe you'll find more information about what you're looking for here: https://en.wikipedia.org/wiki/Residual_sum_of_squares That is correct, but again, be careful with how you interpret this information.
  14. h6ss

    The error between two different standard deviations

    The standard deviation between the two sets makes no sense. No such thing exists. Where did you get this formula from? As I said earlier, you can't just use the difference of the values for both datasets and label it as the standard deviation "between" them. Each dataset has a standard deviation...
  15. h6ss

    The error between two different standard deviations

    What do you mean by that? I don't understand what you're looking for. If you're looking to compare both sets, you usually shouldn't work with the difference of both data sets per value. What you want is maybe the difference between a function (for example the mean) of one and the same...
Back
Top