1. U

    Is multidimensional ROC Curve Analysis a thing?

    Hi, I'm a student of statistics and right now, in my course, we're studying validation of diagnostic tests. While learning about ROC Curves and AUC, I was wondering if does considering ROC Curves in the multivariate context make sense, and if so, how's the analysis performed and which are the...
  2. L

    How to derive multivariate normal pdf from matrix normal pdf?

    I am working on the proof part in Definition section of I can understand what s going on, except for the last part how inv(V(kron)U) becomes inv(U) for multivariate distribution. is there any source you can help me with how to get...
  3. C

    Interpreting mulitiple regression coefficients

    I am quite new to statistics and trying to get a grasp of it with some coronavirus data. So, I have 16 countries and I want to find regression of coronavirus cases by population pyramid. I am using this equation. In my case it looks like this: (Obviously in calculations the first column is...
  4. I

    Problem on Tests on mean and variance

    I need some help. It is a problem from a book called Theory of Multivariate Statistics, by Martin Bilodeau and David Brenner. It is from unit 8 (Tests on mean and variance), problem 14. Does anybody know this :)?
  5. M

    Arthritis trial data: Advanced multivariate stats problem.

    I am a doctor planning a post-hoc exploratory analysis of some clinical trial data and would like some suggestions as to the best approach. Patients with arthritis have many inflamed joints; in clinical trials, doctors test 66 of these for tenderness and swelling. The result is trinary: 0; no...
  6. T

    Can a mixed-effects regression model be used for univariate analysis or just multivariate?

    I'm using a mixed-effects regression model to account for intragroup correlation. Can this be used in both univariate and multivariate analyses?
  7. M

    How to test if gender impacts mortality rates when already considering age

    Hi, I am currently working on a research project where I'm analysing the impact of different factors on mortality. I have the past 10 years of data from a specific hospital and I have graphed the mortality curve by age separately for males and females. I can see that the one curve lies above...
  8. W

    Statistical Tools for Analysis of Effect of Light, Temp, CO2, and pH on Growth Rate

    My question is, what may be the ideal tools to analyze the data from this experiment and what are some resources you can recommend to learn about them (textbooks, website, etc.). I'm also just starting to learn R so feel free to work that in there. I'm designing undergraduate research to be...
  9. W

    comparison of multivariate (4 DV and 1 IV) datasets (data matrices)

    I want to compare 06 different Multivariate datasets (data matrices). Each dataset consists of SAME number of columns but different number of rows. Number of columns represent the variables (4 dependent variables and 1 independent variable). All variables are quantitative in nature. Independent...
  10. I

    Help with regression and related nominal values

    Hey all. I'd like some input on a regression analysis. I have data that measures the reactions of individuals to a number of objects and to a number of questions. It looks something like this (Q=question): Q1 Q2 Q3... Obj1 45 23 52 Obj2 65 67 02 ... I have...
  11. I

    Multivariate models - standard error help

    I have 2 multivariate models created in R concerning nutrition Model 1 = -11.5±1.68 + 0.56±0.562 Intake + 16.6±0.165 Potassium concentration Model 2 = 16.6±0.123 Potassium concentration Both of these have come from the same data set. My question is, is it right that the standard error...
  12. 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...
  13. J

    Individual vs. Team Aggregated Data

    I have a set individuals (let's say ID_No 1 through 50) and a set of metrics that pertain to these individuals: things like age, SAT reading score, SAT math score, a motivation index metric, etc. These individuals are also aggregated into teams (let's say ID_No 1 though 10 is team 1, ID_No 11...
  14. S

    which test for repeated measures within-between group change with small sample size?

    Hi all, I have an intervention study with a very small sample size and am trying to decide the best way to analyze it. Any suggestions would be extremely helpful. Here is some more information: Measurements on 5 different variables were taken at 3 time points: Baseline, Follow-up 1...
  15. K

    Multivariate correlation coefficient?

    Is there a simple definition (formula) for a multivariate correlation coefficient between k binomial variables, assuming that each variable is positive with the same probability/frequency f? What does the CDF for this multivariate binomial distribution look like, and how does it depend on the...
  16. K

    imultivariate analysis?

    Hi, I have some data looking at a few variables and whether they are different for patients receiving/not receiving certain treatment. They are a mixture of proportions & means & some of them are probably dependant. So far I've used t test for the means & z tests for the proportions. Its...
  17. N

    Non parametric multivariate analysis?

    Hi this is a pretty straightforward question, what analysis allows multivariate analysis that is also non parametric? I would like to analyse the relationship between one response variable(continuous, non normal data) with 2 independent predictor variables(both categorical). So the anova...
  18. S

    Repeated measures GLM - restricted permutations

    Hi all, I have some multivariate data (species counts) and want to investigate the effect of some treatment over time. I am using the mvabund package in R, which fits a separate GLM to each species. Specifically, my data are invertebrate taxa collected from pitfall traps under two...
  19. S

    Test on Two Mean Vectors

    Hello. I am currently taking a multivariate statistics course and having trouble with this problem. Test Ho: μ' =(6,11) ....... 3 10 Y = (6 12) ...... 5 14 ...... 10 9 I know I need to find the combined T^2 but am not really sure where to start or what steps to...
  20. G

    Eigenvectors of SSE^-1*SSH

    I'm in my Multivariate Analysis class and I'm having a few difficulties with coding in SAS. Would anyone be able to point me in the right direction to where I can get help with calculating the eigenvectors(a_1,a_2,...,a_sub_k) of the matrix SSE^-1*SSH by way of using SAS Enterprise Guide...