When analyzing many variables, scatter plots and correlation coefficients can quickly uncover patterns and reduce a large amount of data to a subset of interesting relationships.
Correlation describes the strength of relationship between two variables. A correlation coefficient ranges from -1 to +1. +1 indicates a perfect positive linear relationship, and -1 indicates a perfect negative linear relationship. Zero indicates the variables are uncorrelated and there is no linear relationship. Normally the correlation coefficient lies somewhere between these values.
The scatter plot matrix shows plots for all of the pairs of variables, and each plot shows the relationship between a pair of variables. The red ellipse contains the middle 75% of the neighborhoods and indicates whether the two variables are positively, negatively, or not correlated.
The correlation matrix shows the correlation coefficient for each pair of variables. Positively correlated variables are blue and negatively correlated variables are red, with the intensity dependent on the magnitude of the correlation.
