COMMAND(1)

NAME
lstat - compute simple statistics on lines of data

SYNOPSIS
lstat [options] files

DESCRIPTION

lstat computes simple statistics on columns in files, such as column means, standard deviations, t-tests or F-tests and paired t-tests on a pair of columns. If the first filename is "-" then stdin is used. The first column is counted from 1. Columns are selected by a list of columns and column ranges. A range 3-7 means the columns 3 to 7 inclusive. lstat is intended to be used on the ".trial" files output by ttest. The -T option makes certain changes that make output compatible with TeX tabular mode. Either statistics are computed for a single file, or with the -F option, statistics are computed differentiating the first file from the remainder. When comparing columns, it is done on a line by line basis, so the paired t-test is used. To check output from ttest for "hypo" files of training set size 1000, do
    lstat -v 1-3,5 hypo.trial.1000*
This prints statistics for columns 1,2,3 and 5. To do a paired t-test comparing the performance of "mdl" and "cart" trials (see ttest(1)) do
    lstat -F -s 1,2 hypo.trial.1000mdl hypo.trial.1000cart

OPTIONS

-2  Use a 2-tail t-test. Default is 1-tailed.

-a col-list
    Print the mean of each column in col-list.

-A col,col-list
    Print the mean of the difference between the col-th column and each column in col-list.

-b  Skip the leading filename and totals, so only statistics are given.

-C col,col-list
    Print the mean, standard deviation, t-score and F-score of the difference between the col-th column and each column in col-list.

-d  Be verbose during operation.

-e  Suppress usual error reporting.

-f prec
    Floats are to be printed with prec decimal places after the point, default is 4.

-F  Statistics are now computed as the difference between corresponding columns in the first file and subsequent files, with columns are paired as before for the paired t-test. In this mode, -s and -S options are identical, etc.

-n text
    In the output, precede the last field specified with a -s, -v, -V option, etc., with the text text.

-p col-list
    The comma-separated list of integers, col-list, specifies which columns are to be printed as percents.

-q items
    Only display this many items on a line of output.

-s col-list
    Print the mean and t-score (difference from 0) of each column in col-list.

-S col,col-list
    Print the mean and the t-score of the difference between the col-th column and each column in col-list.

-t text
    Seperate fields in the output with this text. For use with -T option.

-T text
    Make output compatible with TeX tabular mode. Damn useful for subsequently generating tables. text is printed before anything else. If a second -T option is used, then its text is printed right at the end.

-u col-list
    Print the mean and the sample standard deviation of the mean for each column in col-list.

-U col,col-list
    Print the mean and the sample standard deviation of the mean for the difference between the col-th column and each column in col-list.

-v col-list
    Print the mean and standard deviation of each column in col-list.

-V col,col-list
    Print the mean and standard deviation of the difference between the col-th column and each column in col-list.

SEE ALSO
ttest(1).