# corr | correlation

Calculate auto or cross correlation for 1 or 2 data sets.

corr out <outfilename> <dataset1> [<dataset2>] [lagmax <lag>] [nocovar] [direct]

`out <outfilename>`

Write results to file named <outfilename>. The datasets must

have the same # of data points.

<dataset1> [<dataset2>] Data set(s) to calculate correlation for. If one dataset or the same dataset is given twice, the auto-correlation will be

calculated, otherwise cross-correlation.

`[lagmax]`

Maximum lag to calculate for. If not specified all frames are used.

`[nocovar]`

Do not calculate covariance.

`[direct]`

Do not use FFTs to calculate correlation; this will be much slower.

**DataSet Aspects:**

`[<dataset1>]`

(Auto-correlation) The aspect will be the name of each of the input data set.

`[<dataset1>-<dataset2>]`

(Cross-correlation) The aspect will be the names of each of the input data sets joined by a dash (’-’).

`[coeff]`

Correlation coefficient.

Calculate the auto-correlation function for data set named <dataset1> or the cross-correlation function for data sets named <dataset1> and <dataset2> up to <lagmax> frames (all if lagmax not specified), writing the result to file specified by out. The two datasets must have the same # of datapoints.