In a heatmap matrix, the rows are the observations in a multivariate data set, and the columns are the attributes measured. The attributes might be categorical or quantitative data. The values of these attributes are color-coded and represented as matrix entries. A heatmap matrix might reveal a pattern in the data by showing if the values of different attributes are similar, thus detecting correlations, or it might visualize outliers if one entry strongly differs in color. The data was obtained from the French Institute for Demographic Studies, or INED.
Note: Population is given in thousands.