# Tag Info

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In graph clustering, we want to cluster the nodes of a given graph, such that nodes in the same cluster are highly connected (by edges) and nodes in different clusters are poorly or not connected at all. A simple (hierarchical and divisive) algorithm to perform clustering on a graph is based on first finding the minimum spanning tree of the graph (using e....

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Yes, the silhouette method (which is implemented in sklearn as silhouette_score) is commonly used to assess the quality of clusters produced by any clustering algorithm (including $k$-means or any hierarchical clustering algorithm). Roughly, you can compute the silhouette value for different $k$, then you would pick the $k$ with the highest silhouette value.

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There is a problem with confining Artificial Intelligence to a single definition, because it has become an umbrella term encompassing many fields of science. It has come a long way from the "thinking machines" of the 50s. Actually, the term was coined in a summer workshop in 1956, whose proposal was: The study is to proceed on the basis of the conjecture ...

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A typical clustering algorithm is k-means (and not k-NN, i.e. k-nearest neighbours, which is primarily used for classification). There are other clustering algorithms, such as hierarchical clustering algorithms. sklearn provides functions that implement k-means (and an example), hierarchical clustering algorithms, and other clustering algorithms. To assess ...

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A simple initial approach would be to separate it by position and check for each: Use linear regression: $\hat{salary} = \sum_i \alpha_i * \hat{region}_i + \sum_k \beta_k * \mathbf{1}[\hat{gender}=k]$ and now you have an intuitive measure by looking at $\alpha$'s and $\beta$'s. 2 issues that may arise with this method: This assumes though that a linear ...

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I report three definitions of machine learning (ML) and I also explain that ML can be divided into multiple sub-tasks or sub-categories in this answer. However, it may not always be clear why classification, regression, or clustering can be considered machine learning tasks or can be solved with ML algorithms/programs, so let me explain why these tasks can ...

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One problem with clustering algorithms is that they will typically find you a solution, ie they will split your data set into clusters, but it will find you a structure even if there isn't one. Your data looks like it could consist of about 5 to 7 clusters, but it could equally well just be 2 or only 1. What you need to do after the clustering is to assess ...

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Yes, you could use clustering: Encode your features as a feature vector and feed it into a clustering algorithm (see Finding Groups in Data for a comprehensive description of these). You could use agglomerative clustering, which would give you groups of similar items; perhaps different level headings will be clustered together. Alternatively you could try a ...

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So, I've prepared some data that resembles your sketch: n , u = np.random.normal , np.random.uniform x = np.concatenate([ n(1.0,0.2,100), n(3.0,0.3,100), u(0,10.0,100)]) y = np.concatenate([ n(7.0,0.4,100), n(5.0,0.3,100), u(0,10.0,100)]) # lets shuffle it a bit idx = np.arange(x.shape) np.random.shuffle(idx) data = np.array([x,y])[:,idx] And then I just ...

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Yes you can use KNN algorithm to cluster (well actually its a classification not a clustering if you use KNN) the data. But, first you need to set one feature as a label because KNN is a supervised learning method, it need a labeled data to train the data first. For example you can use Gender as label to classify the data. To determine the quality of the ...

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I shall suggest one more popular metric for this. Davies Bouldin Score (https://scikit-learn.org/stable/modules/generated/sklearn.metrics.davies_bouldin_score.html#sklearn.metrics.davies_bouldin_score). You can also take a look at the clustering metrics in scikit documentation (https://scikit-learn.org/stable/modules/classes.html#module-sklearn.metrics).

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You can compute "Silhouette Coefficient" for your aim. Its values mean: 1: Means clusters are well apart from each other and clearly distinguished. 0: Means clusters are indifferent, or we can say that the distance between clusters is not significant. -1: Means clusters are assigned in the wrong way. Also other measures such as purity and mutual ...

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In spectral clustering we not find the eigenvectors of a graph (a graph is not a matrix) but the eigenvalues/eigenvectors of the Laplacian matrix related to the adjacency matrix of the graph: graph => adjacency matrix => Laplacian matrix => eigenvalues (spectrum). The adjacency matrix describes the "similarity" between two graph vertexs. ...

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Its not required, you can have $m=1$, actually it can be any number $\geq 1$. Now the better question is why to have it? The answer is that it adds a smoothing effect. Lets look at it in each of the limits ($\lim m \rightarrow 1$ and $\lim m \rightarrow \infty$) Towards $\infty$, it makes $u_{ij}$ equal to $\frac{1}{c}$, making each point have equal ...

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If you look at Kaufman & Rousseeuw (1990), Finding Groups in Data, they describe an algorithm to evaluate the quality of clusters in agglomerative clustering. You run the clustering algorithm with a specific value k for the number of clusters you want, and that routine then gives you a score to reflect the cohesion of the clustering. If you then cluster ...

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This is the classic question of what structure is or can be. It relates directly to the concepts of generalization, pattern recognition, over-fitting in surface fitting strategies, and learning tabula rasa, Latin for blank slate. The underlying questions are these: How can it be determined whether the organization of data in a set, which appears to ...

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