All Questions
Tagged with environmental-data r
14 questions
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Interpreting NMDS environmental correlations in the context of spatial and temporal autocorrelation
Do I need to account for autocorrelation when assessing correlations of environmental variables on an NMDS (nonmetric multidimensional scaling) ordination of species data? If so, how?
Data + setup:
I'...
- 2,345
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78
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Can I use a GLM in R to analyse the relationship between time-series environmental variables?
I have a water quality sensor which is measuring various parameters every hour for one year in the same location. I would like to analyse the relationship between each of these parameters and ...
- 11
2
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2
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796
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Need to scale environmental variables when correlating to NMDS axes?
I've created a Non-metric MultiDimensional Scaling (NMDS) ordination from a Bray-Curtis dissimilarity matrix. (Starting data were basal areas of various tree species across multiple research plots).
I'...
- 2,345
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How to choose the equally spaced values for temperature variable in R? [closed]
I am learning a distributed lag non-linear model. In that, I have to create a cross basis matrix first. For cross-basis, I need to specify the knots at equally spaced values of the temperature ...
- 11
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36
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What is the best way to do a metanalysis for half-life?
I am working on a meta-analysis on pesticide degradation, where the quantity of interest is the difference in half-life in different environments. However I am in doubt of how to use the data; in all ...
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84
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How to analyse temporal variation in R---vigilance of birds
I am currently doing a project for my Bachelor degree, for which I study vigilance in birds. Obviously, I have to analyse the data statistically. However, I do not know where to begin since I do not ...
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finding the correlation between population density in a city and the city's PM 25 value
I am a high school student doing a report for my environmental science course, IB diploma.
My question is about how to find the correlation between two data sets.
My question of interest is whether ...
- 11
1
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1
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7k
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Preparing data for cross-correlation time series
I have several data sets with air quality measurements for 20 locations. The measurements were done per second over a period of two weeks, 5 locations per period (because there were only 5 instruments)...
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4
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3k
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R vegan: RDA vs CCA, which test to answer my research question and which results to report?
(if my question should be cut up into sub-questions please let me know, since all those questions are related I decided to ask them here together as one long question)
Main question
As part of my ...
- 41
0
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1
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428
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Structural change analysis validity in case of auto-correlated data?
I attempted to assess the "significance" of some environmental alteration through the identification of break points in a diagnostic time series (using R strucchange...
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4
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2
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855
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What to do if time series data remains autocorrelated?
Data:
I have 92 years of monthly climate data. One of my variables is a drought index (SPEI) ranging from -2 (dry) to 2 (wet).
All the data can be found here.
Data Structure:
...
- 2,345
2
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0
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353
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Population genetics: analysis of allele frequency distribution along environmental gradients
Is there a software or a R package that does a simulation of spatial distribution of alleles? I'm interested in how a distribution of alleles of functional loci is shaped by a pattern of environmental ...
- 95
2
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1
answer
2k
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How to compute a measure of distance between sites with continuous variables?
I have a dataframe with each row being a different site (51 sites), and each column being mean values of a different continuous environmental variable (19 variables).
I am trying to calculate a ...
- 21
2
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0
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805
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Compositional analysis vs. Manly selection ratios
I am comparing habitat availability vs. use by a bird species using the R compana() function (package adehabitat) which uses Aebischer et al. (1993) method. It is a ...
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