cormatrix: A Function to Create a Correlation Matrix
In matthew-quesnel/simplePsych:

Description Usage Arguments Examples

This function allows you to print the output of data frames and most R functions in an APA formatted table.

cormatrix(ivs = NULL, data = "NULL", method = "pearson",
  output = "r", means = FALSE, columnnames = TRUE, CI = FALSE,
  CIlevel = 0.95, displayDF = FALSE, displayP = FALSE,
  showSig = TRUE, digits = 3)

`ivs`	List of variables from which to compute all pairwise correlations. Input must be a list (i.e., c("var1","var2")). Defaults to NULL.
`data`	A data frame containing the observed variables to correlate. Defaults to NULL.
`method`	Type of correlation coefficient to computed. Options include "pearson","kendall", or "spearman". Defaults to "pearson".
`output`	the format desired for output. Options include "html" or "r". Defaults to "r".
`columnnames`	Option to determine whether variable names are used as column headers (TRUE) or numbers are used instead (FALSE). Defaults to TRUE.
`CI`	Option to include confidence intervals in the correlation matrix table. Defaults to FALSE.
`CIlevel`	If confidence intervals are requested, this sets the desired confidence interval. Defaults to .95
`displayDF`	Option to include the degrees of freedom used in each test in the correlation matrix table. Defults to FALSE.
`displayP`	Option to include the statistical significance (p-value) of each correlation in the matrix. Null hypothesis that there is no relationship between the variables (r=0). Defaults to FALSE.
`showSig`	Option to include symbols beside correlation coefficient denoting the level of significance of each correlation. Levels include p < .1, p < .05, p < .1, p < .001. Defaults to FALSE.
`digits`	Number of digits you want to round numbers too. Leave blank if you don't want to round numbers or if the Data Frame contains strings. Defaults to NULL.

1	cormatrix(ivs = c("mpg","wt","hp"), data=mtcars, digits=3, output="html", columnnames = FALSE, CI=TRUE, CIlevel=.95, displayDF=TRUE, displayP=TRUE, showSig=TRUE)