when do they need correlation matrix when do we use correlation matrix what is the correlations of variables? how many years for a correlation matrix how long to show the correlations between variables based on the time span of research? how to show correlation in a historical event how to find the correlations during an event history analysis using r how many years to use correlation matrix how to show correlations between variables how many years of correlation in event analysis what is a correlation analysis when should i use correlation matrix what is the correlation matrix of statistics for events how many years in correlation matrix how to show correlation coefficients between variables how many years of data is included in a correlation matrix? how to find correlations between variables for event how long to show correlation between variables how many years of variables in the r correlation matrix which of the following is a correlation matrix used in a research study