Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [ward]

Ward's method is one of "linkage rules" in hierarchical agglomerative cluster analysis. In Ward's method, those two clusters are chosen to merge at each step that would yield the lowest increase in error sum of squares.

Ward's method is a rule for determining which clusters to merge next during hierarchical agglomerative clustering. In Ward's method, the 2 clusters that would yield the lowest error sum of squares are chosen.

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Is it ok to use Manhattan distance with Ward's inter-cluster linkage in hierarchical clustering?

I am using hierarchical clustering to analyze time series data. My code is implemented using the Mathematica function DirectAgglomerate[...], which generates hierarchical clusters given the following inputs: a distance matrix D the name of the…
Rachel
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What algorithm does ward.D in hclust() implement if it is not Ward's criterion?

The one used by option "ward.D" (equivalent to the only Ward option "ward" in R versions <= 3.0.3) does not implement Ward's (1963) clustering criterion, whereas option "ward.D2" implements that criterion (Murtagh and Legendre…
Raffael
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Is there an advantage to squaring dissimilarities when using Ward clustering?

Is there a reason to prefer squaring or not squaring the dissimilarities when clustering with Ward's method? The question is motivated by the following statement in the documentation for R's hclust() function: Two different algorithms are found…
bigTree
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Gower's (dis)similarity index

I would like to ask a question about Gower similarity/dissimilarity index. Is it ok to use the Gower dissimilarity measure with Ward linkage clustering? I was reading that the Gower similarity index should not be used with Ward linkage because the…
M. Tremmel
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How does "ward" clustering (in R's hclust function) work?

A simple example: plot(hclust(dist(c(1:3)),method = "ward")) I would like to know which calculations (in R) can reproduce the distance of 3 from {1,2} to be 1.67 Thanks.
Tal Galili
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Applying Ward's method for calculating linkage

For an assignment, I have used iPython to create the dendrogram below, using Ward's method and Euclidean distance, from the following data: $$a=(0,0)$$ $$b=(1,2)$$ $$c=(3,4)$$ $$d=(4,1)$$ $$e=(2,2)$$ where dist({a},{b,e}) = 2.88, and…
Harr
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A high cophenetic correlation coefficient but dendrogram seems bad

I have 2 results for the same dataset. One is hierarchical clustering using Ward's method and I got 0.75 cophenetic correlation coefficient. The second is average method and I got 0.91 cophenetic correlation coefficient. I used "euclidean distance"…
Emrah Bilgiç
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Which similarity coefficient should I use with Ward linkage?

I just attempted implementations of Ward linkage and UPGMA linkage, as well as Pearson and Euclid similarity coefficients. To my surprise, both similarity coefficients gave the same clustering with the Ward linkage. Should this be the case? Is…
Jared Olerend
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Hierarchical clustering Ward's method. The missing rationale in derivation

The Ward's method is taking distance as how much the sum of squares will increase when we merge them. $d(u,v) = \frac{|u||v|}{|u|+|v|}{|m_u-m_v|}^2$ Please refer to Page 3 of link…
DongukJu
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How to interpret the numeric values for "height" in a dendrogram using Ward's clustering method

I am a biology student investigating a new method of creating a dichotomous identification key. I have created a dendrogram using data I have collected from a survey on how people rate how similar pictures of plant leaves are. I used ward's method…
radellin
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Gower's dissimilarity measure and Ward's clustering method

I have read some threads on this website saying that it is not OK to use Gower's dissimilarity matrix for Ward's clustering algorithm. I have mixed type variables, first I had a dissimilarity matrix with Gower's formula in R (daisy function). I had…
Emrah Bilgiç
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Difference between Ward hierarchical clustering and K-Means for classification

I have a dataset where of socio-demographic features of a population (expressed as percentages over the total population of the municipality: e.g. 12% of freelancers, 5% of unemployed etc.), each observation is a municipality of the city. My goal is…
sato
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Step-by-step: Ward's method for calculating linkage

I'm trying to use Ward's method to calculate linkage for hierarchical agglomerative clustering with the data points below: $$a=(0,0)$$ $$b=(1,2)$$ $$c=(3,4)$$ $$d=(4,1)$$ $$e=(2,2)$$ According to some…
Harr
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Why does the row order of the sequences in TraMineR influence clustering results (Wards method)?

We have a large sample (44,933 sequences each of potential length 35) with 9 states. We create a standard dissimilarity matrix: seq <- seqdef(data, 3:37, right="DEL", left="DEL", gaps="GAP", indel=3, id=data$id, weights=data$weight) Then create the…
Larry
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How to validate clusters after calculating Gower distances and Ward's clustering in R

I am trying to apply Ward's clustering on a mixed types dataset, and wanna explain what I did (maybe helpful to others), and I have some questions regarding this analysis, mainly how to validate my clusters. So, let me explain what I did in…
ItK
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