compositional data and compositional data analysis, refers to varibles representing proportions, so non-negative and always summing up to one. See https://en.wikipedia.org/wiki/Compositional_data

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Eliminating noise / contamination in compositional data

I have data in compositional form. That is a matrix where the columns (each column is a sample) sum to 1. So, each element i,j in the matrix is the fraction of ...
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Are crossplots of closed-sum attributes from independent analyses valid?

Some geochemistry papers that I have read contain crossplots of compositional components that resulted from different analyses of a rock sample. For example, one is the percent volume of TiO$_2$ ...
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Visualizing composititional time series with negative values and meaningful totals

I have a compositional time series containing negative values, like this: ...
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70 views

Distance matrix for multiple compositional data

Each data point in my data set is a "multiple compositions" (I'm not sure if this is the correct word for this kind of data). For example: Data point $X_i = \{a_1, a_2, a_3, b_1, b_2, b_3, c_1, c_2, ...
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Calculating Autocorrelogram for Compositional Time Series in R

How would I calculate the autocorrelogram for a compositional time series in R?
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Picking Optimal Sampling Frequency in a Longitudinal Experiment

I am trying to design an experiment to determine the scale at which an underlying process is occurring in a multivariate time-series of counts (alternatively it can be viewed as trying to find the ...
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35 views

Mutual Information based Correlation Measures that are Robust to Compositional Data

Are there mutual-information based correlation measures that are robust to compositional data? It is my belief that many of these methods (e.g., distance correlation, transfer entropy, MIC, ...) may ...
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Which model to use when you have multiple proportion independent variables?

I want to do a regression analysis (as I have found out on What regression model to use when independent variables are percentages to predict % outcome? should probably be a logistic regression) but ...
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339 views

Problems with time series prediction

I got a question about modeling time series in R. my data consist of the following matrix: ...
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Overall $p$-value for a multiple linear regression (in MATLAB)?

I wish to explore the effects of the component percentages (independent variables) on fruit sweetness $S$ (dependent variable). Assume for simplicity that our fruit only contains 3 components, ...
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Proportions (compositions) in logistic regression

I have a logistic regression where some of the independent variables are proportions (compositions) that sum to 100 percents. Let's say that I have 4 such variables - I have ran the regressions 4 ...
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Understanding biplot for compositional data

Say in the biplot of some compositional data, I discovered that the links $\vec{AB}$ and $\vec{CD}$ intersect at roughly 90 degrees. So I can say that $\log {A\over B}$ and $\log{C\over D}$ are ...
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246 views

Multivariate data analyis of compositional data

Suppose I have a multivariate, compositional dataset that depicts the concentration of different elements. However, the data are not available on a single scale; i.e., some are of form 0.00x while ...
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Which variables should I transform, center, and/or standardize in my data for Principal Component Analysis?

I have multiple datasets that I am attempting to use principal component analysis (PCA) on in order to infer the underlying structure of the data. I'm attempting to predict growth increment of ...
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Finding mean and SD of 2 parts of a whole

I am putting together a review/meta-analysis of body composition in children. The data I will analyze consists of measures of fat-mass (FM) and fat-free-mass (FFM), which when summed equal total ...
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705 views

Analysing data measured as proportional composition

I have a data set on the proportional composition of marine substrate for different locations which I would like to compare. For example, one replicate transect within a location may be 50% sand, 25% ...
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108 views

Binomial GLM with unknown totals?

Essentially, I have some covariate data X, and a dependent variable Y consisting of proportions of a sample that shown a certain ...
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314 views

Multivariate proportional data

I am looking for literature on what I call multivariate proportional data where a single observation is a vector of proportions that sum to 1. For example, each person weights their preferences for ...