Many dataset these days are collected at different locations over space which may generate spatial dependence. Spatial dependence (observation close together are more correlated than those further apart) violate the assumption of independence of the residuals in regression models and require the use of a special class of models to draw valid inference. The first … Continue reading Spatial regression in R part 1: spaMM vs glmmTMB
In September last year I was starting to put together my first ever proposal to basically write my own PostDoc position that would give me an extra three years of academic research fun. Today I received the final feedback from the panel (which was negative but more on that below) and I thought that I’d … Continue reading Just one paper away: looking back at first scientific proposal experience
After all the hard work of collecting the data, thinking about appropriate models, formatting the data, you are finally running your model, this is it you are going to get the long awaited results and BOUM you get out such kind of message: ## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = ## control$checkConv, : Model … Continue reading Help! I have convergence warnings
Another year of blogging has passed, now is the time to look back, look at some numbers and think a bit about the coming of a bright new year . Looking Back In 2017, I posted 16 articles. The majority of them (7) were stats and/or R-related, showing how to perform a certain kind of … Continue reading Review of the fun 2017
This is a quick post on a blatant example on how careful and prudent interpretation in scientific articles are over-simplified in news article. Scrolling through lemonde.fr website I found this article about a long-term study that looked at the long-term changes in insect biomass. In this article one can reads: 'Le facteur majeur permettant d’expliquer … Continue reading Mind the gap: when the news article run ahead of the science
A reader asked in a comment to my post on interpreting two-way interactions if I could also explain interaction between two categorical variables and one continuous variable. Rather than just dwelling on this particular case, here is a full blog post with all possible combination of categorical and continuous variables and how to interprete standard … Continue reading Interpreting three-way interactions in R
Point pattern analysis is a set of techniques to analyze spatial point data. In ecology this type of analysis may arise in several context but make specific assumptions regarding the ways the data were generated, so let's first see what type of ecological data may or may not be relevant for point pattern analysis. What … Continue reading Introduction to point pattern analysis for ecologists
This is a theme that bugged me for the past few months, through reading (Peters' critique for ecology, Shipley's path analysis book), meetings and discussions (IK computation ecology). So it is time to actually sit down, think this through and organize my thoughts. What better way to achieve this than to write a post? What … Continue reading Cause, mechanism and prediction in ecology
Sometime I happen to be wrong, this is one of these instance. The issue: a colleague measured individual plant growth and measured light irradiation received by each individual, the plants where in groups of 10 individuals and he measured soil parameters at the group-level. To analyze the effect of light on plant growth while controlling … Continue reading Adding group-level predictors in GLMM using lme4
With my higher education studies behind me, I wanted to reflect a bit on the different amount of tuition fees that I experienced moving around European universities. Stage 1: France I started in 2008 with a Bachelor of science in Strasbourg, at that time you had to pay around 500€ for a year. In these … Continue reading On the price of (my) higher education
biologyforfun 