packhorse

Support for small to medium data manipulation and analysis projects, including numeric and categoric data list-like structures and data frames.

Usage

A simple usage example:

import 'package:packhorse/packhorse.dart';

main() {
  final data = Dataframe
  // Read in the data.
  .fromCsv("""
    distance,percent
    0 to 1,22
    1 to 5,30
    6 to 10,17
    11 to 15,8
    16 to 20,6
    20 to 50,17
  """)
  // Add a numeric column from a template of categoric data.
  .withNumericFromTemplate("midpoint", "{distance}", (value) {
    final datum = value.split(" to "),
        lower = num.parse(datum.first),
        upper = num.parse(datum.last);
    return (lower + upper) / 2;
  })
  // Add a numeric column from a formula of numeric data.
  .withNumericFromFormula("contribution", "midpoint * percent / 100");

  print(data);
  print("Mean distance: ${data.nums["contribution"].sum}");
}

Output:

.--------.-------.--------.------------------.
|distance|percent|midpoint|      contribution|
:--------+-------+--------+------------------:
|  0 to 1|     22|     0.5|              0.11|
|  1 to 5|     30|     3.0|0.8999999999999999|
| 6 to 10|     17|     8.0|              1.36|
|11 to 15|      8|    13.0|              1.04|
|16 to 20|      6|    18.0|              1.08|
|20 to 50|     17|    35.0|              5.95|
'--------'-------'--------'------------------'

Mean distance: 10.440000000000001

Also provides support for more complicated manipulation, joins and filtering. See the project wiki for further information and examples.

Features and bugs

Please file feature requests and bugs at the issue tracker.