monte carlo

  1. G

    Coin probability problem

    We throw the coin 1 000 000 times. How many times on average will make 13 successful heads? Now the problem with the naive: 1 000 000/(2^13) is that once it made 13 heads the 14 head will happen with 1/2 probability , but it will count as 2 13 successful heads. 15 will happen 4xtimes less, but...
  2. B

    Looking for the best way to use my available data in a predictive model

    I have several pieces of data available, but I'm not sure about the best use of it in a predictive model. I envision using a regression, then plugging the predicted values into a monte carlo simulation for optimization. I'm wondering how an experienced statistician would use the available data...
  3. trinker

    Monte Carlo Simulation for Predicting Agile Stories Completed

    A team at work saw this post on using MC for predicting a forcast of stories completed: http://scrumage.com/blog/2015/09/agile-project-forecasting-the-monte-carlo-method/ I have a series of questions as I know of Monte Carlo Simulation but have not used them. 1. Is the basic gist: Get mean and...
  4. Y

    Unbalanced designs in PERMANOVA and Resampling Methods

    Dear all, I am a new member and I have to say I am not sure if this is the right section for my question (I am working in ecology). I am dealing with unbalanced designs (I am comparing groups with different sample sizes) in PERMANOVA (Permutational Multivariate Analysis of Variance). The...
  5. G

    Sum of log normals not log normal; Monte Carlo Simulation

    The Problem is this: Let X1, X2 be two normaly distributed R.V. with equal Variance sigma, expectation 0 undCorrelation Rho. I Would like to: 1) simulate X1 and X2 jointly in excel; 2)simulate exp(X1) und exp(X2)jointly in excel ; 3) simulate exp(X1) + expe(X2); 4) show, that...
  6. M

    Monte Carlo Simulation , a simpler version

    Hi all, I have asked this question before, but it seems I was not asked it in an appropriate way, so I draw the following flowchart which I think explain the problem much simpler and faster. I have the following situation and would like to do a Monte Carlo Simulation for this. Could you...
  7. M

    Monte Carlo for Weibull and Lognornam distributions in R

    I am involved in a project which needs statistic and computer science. I am more of a computer guy so I appreciate any statistical help. I am doing most of the process in R. Step A: In the project, I have some sensors which count the number of passing objects in minutes and these sensors...
  8. J

    Monte Carlo simulation

    Hi :) I'm currently doing a third year university stats course. I need help with some questions. The question gives Wind speed and Temperature data. It then asks to do linear regression to determine the relationship between them, which I've done. (explanatory variable is Wind speed) It...
  9. spunky

    Good sources (books, articles, ....) on the history of Monte Carlo methods?

    I am finally entering the final step of my PhD. Chapter 1 of my dissertation has already been published, Chapter 2 has been submitted for publication and Chapter 3 is kind of in the middle. I just need to stick an Intro and a Conclusion and we'll call it a day. But, before that, I need to...
  10. W

    Determine the risk (probability) of meeting forecasted demand

    Hi, I'm doing a project for a car company for my final year studying Industrial Engineering. The company forecast demand 4 months ahead but, according to history data, the company rarely meets the forecast demand. The Supply Chain Department asked me to develop a model that would, with...
  11. B

    Excel Simulation (Monte Carlo) help

    Hi all, I've been racking my non-statistical brain on my Excel simulation (monte carlo sim predicts profit). I have created the model and as I review the outputs, I'm not confident that it's correct. With that said, is there anyone who could review it and let me know if you see any obvious...
  12. K

    Monte-Carlo simulation of repeated-measures ANOVA

    Hello, I want to conduct a Monte-Carlo simulation of a repeated-measures ANOVA. The random numbers used for the simulation need to have specified mean values, standard deviations and correlations between the levels of the repeated-measures variable. Generating random nubers with a...
  13. A

    Monte Carlo simulation: how many runs?

    Hi, Most papers I read related to Monte Carlo (MC) simulation method say that there is no rule on the minimum number of runs required. However, in book Risk Analysis by D. Vose there is the following formula for the estimation of the true mean: n>\left ( \frac{\Phi ^{-1}\left (...
  14. K

    Compensating errors; normal distribution; subset; monte carlo simulation

    Hi all, Please forgive the slightly long winded explanation, I could really do with some help here. I have a computer simulation which contains multiple variables to which I have applied random perturbations in order to simulate the possible error. The random perturbations are in the form...
  15. S

    Correlation between two non stationary time series

    Hey everyone, I'm trying to figure out if there is significant correlation between two non stationary time series (e.g. temperature on a a given day and icecream sales). Could someone please propose a method. There are so many different methods i read about online im not sure which to go...
  16. G

    Monte Carlo simulation for interviewing data?

    Hello everyone, I have interviewing data that includes interviewers' ratings of applicants and job performance ratings. I would like to test how changing the interviewers' ratings (e.g., giving some a leniency affect by bumping their scores up by 1/2 SD) would affect the validity of the...
  17. E

    Quantile prediction?

    Here is my situation. I am trying to predict the 'entire' distribution of the dependent variable, not just the mean( or conditional mean). Does it then make sense to seprateley predict quantiles of this variable to learn about the new predicted CDF? I intend to use this CDF as one input (say...
  18. A

    Difference between VCV by inverting Hessian at ML and by Hierarchical Bayes

    Let's say we have a multimomial logit problem and we find the best beta coeffcients b* aggregating all units. The inverse of the Hessian at b* gives us a VCV matrix at this point which shows roughly how betas vary across units. The other way to get a VCV matrix is to use Hierarchical Bayes where...
  19. C

    Improved Monte-Carlo method vs. hit-and-miss method

    I am not understanding *Which is more accurate, the hit-and-miss method or the improved Monte-Carlo method?* http://www-stat.stanford.edu/~susan/courses/s208/node14.html it is written that that the hit-and-miss has a higher variance but they showed (variance of improved Monte-Carlo) -...
  20. KristinaMac

    Interpreting parameter estimates (ERGM)

    Hi anyone could help me with the following? How do I calculate and interpret departure from non-randomness or likelihood of such configuration occurring using Exponential Random Graph Model with dependence graph construction if I have the following information: - exponential probability...