Recent content by gianmarco

  1. gianmarco

    Is Chi square the appropriate test in this scenario?

    Hello, do you have spatial information about those burrows (i.e., geographic coordinates)? Just wanted to provide you with another perspective: the question could be framed "spatially"; in other words, one could wonder if satellite burrows tend to be closer in space to occupied burrows than to...
  2. gianmarco

    How to interpret the odds ratio (exp(b)) with a continuous dependent variable?

    As far as I remember, a 1-unit increase in the predictor increases/decreases the odss for the positive outcome of the DV by x. I happened to use LR (with both continous and categorical predictors) here: You may want to...
  3. gianmarco

    checking whether I wrote a formula correctly in R

    Thanks @GretaGarbo for welcoming me back. By the way, the formula we discussed about regarding walking speed is for off-road walk...that could account for such slow speed at slope 0. Best
  4. gianmarco

    checking whether I wrote a formula correctly in R

    Hello All, thanks for your input. Yes you are right, I should have provided more context. The problem is that that formula is out from a larger code that I have used in a package of mine that has been released to CRAN abut 1 years ago...
  5. gianmarco

    checking whether I wrote a formula correctly in R

    Thanks Spunky.... what seems peculiar to you is the only thing I know is correct LOL. Forget that, and take it as the "slope" value...
  6. gianmarco

    checking whether I wrote a formula correctly in R

    Hello, I have been off the grid for some time. It's nice to post again something, and I look forward to hearing from you :-) As per title, I am wondering if I wrote correctly a formula in R. The formula, as derived from literature, is attached as an image. It aims at predicting the speed of...
  7. gianmarco

    Appropriate statistical analysis for 2 groups with 3 possible outcomes

    Hello, I think the Cochran-Armitage test may apply to your situation. See this LINK. Best
  8. gianmarco

    Correspondence analysis - fragment of text

    The basic result of correspondence analysis is a scatter diagram – a perceptual map and set of measures that serves to assess the quality of representation of a multidimensional space on a surface. *I believe you may want to drop the reference to "perceptual map" and stick with scatter diagram...
  9. gianmarco

    Correspondence analysis - fragment of text

    If you are willing to post it here, I would not mind to read it. While I know something about CA, that would allow people more knowledgable than me to jump in a provide further help. cheers. Gm
  10. gianmarco

    Statistical test to assess the relationship between an independent and dependent variable of an experiment

    "to use the one-way ANOVA test to determine whether there is a statistically significant relationship between the density of beech and oak trees and altitude" Put that way, I believe 1-way Anova (or, better, a t-test since you have 2 groups) would test if there is a significant difference in...
  11. gianmarco

    Can you use factor analysis on a table has count data?

    You're welcome. This is a nice, extremely easy to follow, article by M. Bendixen about CA in marketing research: A Practical Guide to the Use of Correspondence Analysis in Marketing Research Attached is the CA scatterplot, made with my CAinterprToolspackage, based on Table 6 of Bendixen's...
  12. gianmarco

    spatial regression with (partly) overlapping areas

    Hello, I believe that other forums (more GIS- or Spatial Analysis-oriented) may provide help. Best
  13. gianmarco

    Can you use factor analysis on a table has count data?

    I have seen in liyerature the use of FA for count data, but (to the best of my understanding) it was before the popularization of CA. CA reduces the number of dimensions useful to represent the table graphically, bringing to the fore latent patterns of association between rows and columns. So...
  14. gianmarco

    Can you use factor analysis on a table has count data?

    Hello, For contingent tables like that, Correspondence Analysis is often used. It has some aspects in common to Factor Analysis, being a method of dimensionality reduction; however, CA is tailored for cross-tabulation and count data. CA is used, for instance, in marketing research to understand...
  15. gianmarco

    Submission of package to CRAN: problem grasping an Error

    @trinker: Thanks for asking. As a matter of fact, eventually I managed to solve the issue and to push the package on CRAN. But I cannot remember how I fixed the error. If I am not mistaken, the problem was with the dataset which the function was using in the example. I recall using a dataset...