**Fsdb::Filter::dbrow - select rows from an Fsdb file based on arbitrary conditions**

Select rows for which all CONDITIONS are true. Conditions are specified as Perl code, in which column names are be embedded, preceded by underscores....

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbrowdiff - compute row-by-row differences of some column**

For a given column, compute the differences between each row of the table. Differences are output to two new columns, "absdiff" and "pctdiff". Differences are either relative to the previous column (*incremental* mode), or relative to the first row (...

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbrowcount - count the number of rows in an Fsdb stream**

Count the number of rows and write out a new fsdb file with one column (n) and one value: the number of rows. This program is a strict subset of dbcolstats. Although there are other ways to get a count of rows ("dbcolstats", or "dbrowaccumulate -C 1"...

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbroweval - evaluate code for each row of a fsdb file**

Evaluate code for each row of the data. Typical actions are things like reformatting and other data transformations. Code can include embedded column names preceded by underscores; these result in the value of that column for the current row. The val...

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbpipeline - allow db commands to be assembled as pipelines in Perl**

This module makes it easy to create pipelines in Perl using separate processes. (In the past we used to use perl threads.) By default (as with all Fsdb modules), input is from STDIN and output to STDOUT. Two helper functions, fromfile and tofile can ...

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbcolstats - compute statistics on a fsdb column**

Compute statistics over a COLUMN of data. Records containing non-numeric data are considered null do not contribute to the stats (with the "-a" option they are treated as zeros). Confidence intervals are a t-test (+/- (t_{a/2})*s/sqrt(n)) and assume ...

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbrvstatdiff - evaluate statistical differences between two random variables**

Produce statistics on the difference of sets of random variables. If a hypothesized difference is given (with "-h"), to does a Student's t-test. Random variables are specified by: "m1c", "m2c" The column names of means of random variables. "sd1c", "s...

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC**Fsdb::Filter::dbrowaccumulate - compute a running sum of a column**

Compute a running sum over a column of data, or of a constant incremented per row, perhaps to generate a cumulative distribution. What to accumulate is specified by "-c" or "-C". The new column is named by the "-N" argument, defaulting to "accum"....

JOHNH/Fsdb-2.71 - 17 Nov 2020 05:00:30 UTC