Statforbiology

My name is Andrea Onofri. Data analyses at the University of Perugia. Teaching Experimental methods in agriculture. #rstats, #Rmarkdown, #DataScience

[Statforbiology @onofriandreapg]

Have you been struggling with derivatives, in your research activities? This post explains how they can turn out useful in species-area studies. Check it out at: https://t.co/E1sBouGcKr

[Statforbiology @onofriandreapg]

New book is out. Fully focused on field research in agriculture, with lots of examples relating to crop and pesticide science. R is introduced and used for data analyses. Check it out at: https://t.co/2hXg7mLnoh

[Statforbiology @onofriandreapg]

The Pearson correlation coefficient is often used to describe the joint variability of two response variables from the same plots in designed field experiments. Inferences therof may be totally wrong: check out my results with #rstat and ‘sommer’ pkg at: https://t.co/c1AMGz0VvT

[Statforbiology @onofriandreapg]

Just wondering about how to go back and forth from a variance-covariance matrix to a correlation matrix with #rstats . For a few methods, goto: https://t.co/X42qxXZs02 . If you have other methods to suggest, pls. drop me a line…

[Statforbiology @onofriandreapg]

Sometimes we want to derive information from a model fit, such as the half-life or the LD50. Here is how we can derive standard errors as well. Part 2: go to https://t.co/dqY54dvfQM

[Statforbiology @onofriandreapg]

Sometimes we want to derive information from a model fit, such as the half-life or the LD50. Here is how we can derive standard errors as well. Part 1, go to:
https://t.co/j1e3vngfnb

[Statforbiology @onofriandreapg]

@jonathanbinder Hello Jonathan, these models are nice, but, in practice, the fit is often bad with many datasets! I’d be happy to discuss this with you: drop me a note at my email address!

[Statforbiology @onofriandreapg]

Together with colleagues from US and Denmark, we have just published a new paper about data analyses for seed germination and other time-to-event data in agriculture with #RStats. Happy about this 😀! Check it out here: https://t.co/BSn1VDrma8

[Statforbiology @onofriandreapg]

In agriculture and pesticide research it is fundamental to ask the data the correct questions. In a new post, I am showing an example relating to the check for basic assumptions with #rstats. Check it out at: https://t.co/wlW03Pdp2f

[Statforbiology @onofriandreapg]

In agriculture and pesticide research, we might like to compare different degradation or dose-response curves in a pairwise fashion (is the whole response curve for A different from the whole response curve for B?). A 'how-to' post in my blog, at: https://t.co/iol3mkbVWD

[Statforbiology @onofriandreapg]

@RHenry_UPL If you take the dose as a factor, with a common control, the design is not fully factorial (see this post: https://t.co/oJK8mVmytG). Furthermore, pairwise comparisons with quantitative variables may be either illogical or inefficient (e.g., see https://t.co/WkAXizrW73)

[Statforbiology @onofriandreapg]

In pesticide research, we often compare the efficacy of several compounds at different doses, with a common untreated control. Data analyses may require some care; I have made this point in a new post, at
https://t.co/IzRTXsasyI
#rstats #DataScience

[Statforbiology @onofriandreapg]

In pesticide research or, in general, agriculture research, we very commonly encouter experiments with two/three crossed factors and some other treatment (usually a check) that is not included in the factorial structure. Tips for data analysis are here: https://t.co/oJK8mVmytG

[Statforbiology @onofriandreapg]

Subsampling and repeated measures can occur together. What model do we fit, in that situation? Some hints in my new post, at https://t.co/5uDNSCC7oZ , #rstats

[Statforbiology @onofriandreapg]

@cb_minely Any examples of failing backtransform?

[Statforbiology @onofriandreapg]

Stabilising transformations, in spite of their age, are still a flexible and useful technique to fit linear models to heteroscedastic data. Do not neglect them, just because they are not in fashion! Some updates in my new post; go to: https://t.co/GwTgBr0yyD … #rstats

[Statforbiology @onofriandreapg]

Multi-year data with perennial crops are very different from multi-year data with annual crops and they should be analysed by using different methods. I make this point in a new post in my blog. Go to: https://t.co/xvXTaSIl9S
#rstats

[Statforbiology @onofriandreapg]

As an editor of International Journals, I am surprised to see so many submissions where true-replicates and pseudo-replicates are wrongly put on equal footing. I added a post to my blog to discuss such an issue. Go to:
https://t.co/ct2JkoBYVW

[Statforbiology @onofriandreapg]

A new post is out in my blog. This time, it is a dive in the coefficient of determination, that is often misused in the agricultural literature. Check it out here: https://t.co/GD01xNNMdq

[Statforbiology @onofriandreapg]

Split-plot experiments are rather common in agriculture, but, to my experience, the resulting datasets are not always analysed properly. Some hints here: https://t.co/eIOXisS1xH