Questions tagged [correspondence-analysis]

Correspondence analysis is a dimensionality-reduction and mapping technique for nominal variables. It is often applied to a contingency table to explore visually affinities among row and column categories. If a table is 3+ dimensional the analysis is called Multiple Correspondence analysis.

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MCA output analysis

I am quite lost on how to interpret the output of an MCA analysis. What does a the output of $var$v.test, $var$contrib, $var$cos2 and $var$coord mean respectively? In addition, I don't quite ...
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Multiple Correspondence Analysis -Decision Making Index Stata

I am trying to make a decision making index using MCA. I am using 6 binary variables and the responses are whether the respondent makes these different decisions alone. I read once somewhere the MCA ...
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Display of dimensions in (multiple) correspondence analysis

I am getting into correspondence analysis and was wondering what the correct way is to display more than two dimensions in a biplot. I found examples with biplots showing dimensions plotted in order (...
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Interpreting Multiple Correspondence Analysis Output

I have the following data for Maryland and Virginia with six different capacity types along with what score (1, 3, or 5) each person grades that capacity type. Essentially what I want to do is see if ...
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What assumptions about the data are require for Multiple Correspondence Analysis?

In multiple correspondence analysis, what assumptions about the data are necessary in order to find the principal coordinates for the rows and columns?
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Coding a categorical variable: 0-1 or multiple subcategories?

I'm working with R and want to run a correspondance analysis on a dataset containing, among the others, the following factors: city district: 27 levels, each corresponding to a given district ...
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How to determine which species are biggest contributors to overall variation in community?

I have data on the community of microbes from different soil types, however I do not have any environmental variables, only categorical (sites). I have generated PCoAs with distance matrices, however ...
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Is MCA equivalent to PCA when all variables are binary?

I am looking to apply principal component analysis on binary (true/false) data, and I have come across the "equivalence between PCA and MCA" (Multiple Correspondense Analysis) for binary data, but ...
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MCA and K-Means simultaneously

I was reading the article Multiple Correspondence K-means: Simultaneous versus sequential approach for dimension reduction https://link.springer.com/chapter/10.1007/978-3-319-55477-8_8 I have this ...
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Canonical Correspondence Analysis: how to interpret results

I am using Canonical Correspondence Analysis (CCA) to analyze phytolith abundances (similar to pollen) over environmental gradients. As I am new to CCA, I read some background info. The following ...
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How to view the predicted unimodal response of a Canonical Correspondence Analysis?

I'm trying to understand the predicted patterns of a Canonical Correspondence Analysis (CCA). I understand one of this method's strengths in understanding ecological patterns lies in its assumption of ...
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I have done crosstabs and a Correspondence Analysis, having trouble reporting and interpreting Chi-Squared and Inertia?

I have data on 1500 cases with two variables (color, genus) with 5 colors and 6 genera. I almost had generally equal spread across genus, but one is disproportionately represented and has about twice ...
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Is Multiple Correspondence Analysis applicable to Multi-valued Categorical Variables?

I have a data-set containing only Categorical Variables. I needed to do Principal Component Analysis on the data set. Eventually, I found Multiple Correspondence Analysis and learnt it. But, in MCA, ...
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Is there a specific name for this plot?

This plot represents the popularity of technologies in two "tools", vue and react. In left-top corner are specific technologies for vue but not for react, right-top technologies popular in both tools ...
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What in cross validation from co-correspondence analysis indicates sufficient axes numbers?

The coca function at cocorresp package disponible for R provides a predictive way to relate two biological composition datasets. I need help to understand one step from examples on documentation ...
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No departure from independence term in constrained correspondence analysis

I am used to think of correspondence analysis (CA) as dissecting the weighted departure from independence through singular value decomposition, but I cannot relate this to constrained correspondence ...
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How variables (constrained loadings) are selected in a biplot CCA

I am trying to do a Canonical correspondence analysis (CCA) using the community data and chemical data. I have my family level taxonomic data as community data. In chemical data I have 18 variables: ...
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Should PERMANOVA be used to select factors for Canonical Correspondence Analysis?

I am interested in investigating the relationship between species composition and several environmental factors. My question is whether it is appropriate to use PERMANOVA to select a 'best' ...
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297 views

How to analyse multiple choice and overlapping questions in MCA?

I need to analyze a survey about entrepreneurship which has around 50 categorical variables. Therefore, after some univariate analysis, I want to apply Multiple Correspondence Analysis (MCA) in order ...
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Is there an analog to logit Y-aware PCA for correspondence analysis?

I came across this tutorial of logit Y-aware PCA for dichotomous $Y$s. Does anyone know if there is an analogous procedure for correspondence analysis? It seems that there couldn't be since the Y-...
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R multiple correspondence analysis loadings

I'm running a multiple correspondence analysis in R using the FactoMineR package: ...
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Displaying large number of text labels on a scatter plot

Having too many species in the data, makes the species labels overlap in a plot of a canonical correspondence analysis. This makes it difficult to interpret. Is there a reasonable possible solution? ...
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Correspondence analysis vs chi square

My data: ...
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651 views

Assumptions for Canonical Correspondence analysis

I have been trying to find the major assumptions a Canonical Correspondence Analysis makes when doing its analysis. I have had a hard time finding anything useful. I did, however, find the assumptions ...
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294 views

Do I need to standardize environmental data before canonical correspondence analysis?

I have a dataset of 15 environmental variables (soil physical and chemical properties) and about 25 "species" variables for about 40 sampling sites. I want to do a CCA to analyse the effects of the ...
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How to test for the effects of plant community composition on insect community composition whilst controlling for geographic distance?

I'm trying to test for the effects of plant community composition on insect community composition using ordination, but I need to control for geographic distance. I know CCA can handle three matrices ...
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Minimize shared variance of columns between factors in Correspondence Analysis

I am using correspondence analysis (CA) to analyze a contingency table. In the columns I have statements about some brands (characteristics) and in the rows I have the brands. My aim is to obtain in ...
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446 views

CCA species coordinates relative to ordination surface

I want to display species coordinates relative to an environmental variable using ordination surface (ordisurf in vegan package)...
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I want to run a same result of biplot in R

There is a software called Brandmap$^1$ which can return a biplot from a matrix. I am trying to run the same result in R but the coordinates are not the same. First I input a simple matrix into the ...
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It is possible to apply correspondence analysis to a 2x2 contigency table?

I was wondering if it is possible to apply correspondence analysis to a 2x2 contingency table. Since that correspondence analysis is a method for dimensionality reduction, I think it is necessary to ...
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313 views

Calculate similarity between assortment of grocery shopping basket

I am trying to measure distances between basket assortments in a grocery shopping. I have all information that who buys what in every shopping by online and offline. I want to see the pattern of the ...
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Visualizing a correspondence analysis over time

I have two contingency tables of frequency data examining the same set of variables but at two different time points. I can make two separate before and after correspondence analysis plots but would ...
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Interpreting Canonical Correspondence Analysis (CCA) Inertia - in Vegan

I am wanting to know if I can use the ratio of Constrained/Total Inertia in my CCA to describe 'The variability explained by my constraining variables'. I am asking because I've seen different ...
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How to interpret the results of my correspondence analysis?

Im looking for help interpreting an CA Factor MAP my df is : ...
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1answer
2k views

Correct way to report the results of a Correspondence Analysis and a Principal Components Analysis

I am currently writing up my dissertation and have done a few CA and PCA tests. I know that the output gives principal inertias that have both decimal value and percentage of variance output. I am ...
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Map using correspondence analysis

I was studying by my own correspondence analysis and I got some questions about the map that one gets using this method for some rows and columns. For example the following map: http://www.statmethods....
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How can one interpret the Stata output for Multiple Correspondence Analysis?

As an alternative to conducting exploratory factor analysis on a set of data, with binary responses, I have been suggested to use Multiple Correspondence Analysis (MCA). Following is a curtailed and ...
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Correspondence analysis: how are row principal and supplement coordinates calculated?

How are row principal and supplement coordinates calculated in correspondence analysis (CA)? Specifically, I am looking for a simple example as how to derive them using linear combinations of the row ...
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694 views

How do I interpret a plot of variables created in FactoMineR?

I'm using the FactoMineR package in R to do a Multiple Correspondence Analysis on a large set of data. Specifically, I'm looking for correlations among a set of five categorical variables. I used the ...
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Respondent supplementary points from correspondence analysis using ca package in R?

I am new to correspondence analysis and I'm trying to decipher a paper's application of it. The authors surveyed 100 consumers on attributes that they would assign to different deodorant brands. The ...
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p value in SPSS correspondence analysis

When I did a correspondence analysis to two ordinal data variables with each having six categories I get this table from SPSS. What does this p value indicate? Does this mean there is no ...
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Interpreting biplots in correspondence analysis

I am reading the book by correspondence analysis in practice by Michael Greenacre.It has the following example. How do we find what row profiles are associated with column profiles. In the book it ...
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Applying Multiple Correspondence Analysis when predictors have thousands of levels

I apologize in advance if my english isn't too clear. Please feel free to leave a comment and tell me what part doesn't make sense. I'm currently working on a dataset which contains web data and I ...
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209 views

Multiple Correspondence / Correlation Analysis

I'm a little bit new to statistics, so I'm not sure what I really need. I have a table like the following with some categorical/nominal values (like Gender and Age Group) and a ratio scaled value (...
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multivariate analysis of dependent data

I have some diet data I am analyzing that was collected in different locations at different times (over 3 years). The nature of the sampling resulted in multiple predators at the same location. The ...
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591 views

How many chi-squared distance matrix does correspondence analysis make?

I am trying to understand step by step how correspondence analysis work. Suppose AxB (row x column) frequency matrix, roughly you should: 1) Calculate row and column profiles 2) Calculate chi-...
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Regarding correspondence analysis

Can we use percentage values obtained from secondary source instead of frequency values in the contingency table for using the correspondence analysis? eg: in a contigency table with row variable ...
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311 views

Multiple correspondence analysis with fuzzy coding

I have a data set with six continuous variables. I would like to perform a multiple correspondence analysis (MCA) with fuzzy coding. I was able to create the fuzzy coding, so for each original ...
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Correspondence Analysis - Marketing - Respondent Ideal Points

How would you show respondent ideal points for a related question in the same survey? Specifically, how would you chart each respondents' ideal attribute groupings along the same dimensions created ...
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Detrended correspondence analysis

I have relative abundance data of monkey species in 4 different types of habitat. I would like to use detrended correspondence analysis. Is this a correct way to display my data? If so, how should I ...