Starfruit

A library containing useful utilities, efficiencies, and abstractions to improve over the Dart SDK and dart:math. It takes heavy inspiration from Guava (by Google) for Java, and ports some functions from it.


It takes time, effort, and mental power to keep this package updated, useful, and improving. If you used or are using the package, I'd appreciate it if you could spare a few dollars to help me continue to do so.

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Classes

Note: https://pub.dev/documentation/starfruit/latest/starfruit/starfruit-library.html is auto-generated dartdocs. This has a more detailed rundown of every class and method. It's impossible to list every method offered and its purpose, so I won't try. You should use the usage examples and documentation to understand the utilities of this library. For here, I'm just offering basic details on how to instantiate every class.

StarMathUtils (mathUtils)

To use, call methods on the singleton instance mathUtils (e.g. mathUtils.chunks([1, 2, 3, 4, 5, 6], 2) ).

StarCollectionUtils (collectionUtils)

To use, call methods on the singleton instance collectionUtils (e.g. collectionUtils.chunks([1, 2, 3, 4, 5, 6], 2) ).

StarStats (List<num>)

To use, collect a list of numerical input data. You can then call StarStats methods on it, because StarStats is defined as an extension on List.

StarStatsXY (Map<num,num> of points)

To use, collect input data formatted {x1: y1, x2: y2, x3: y3, ...}. You can then call StarStatsXY methods on it, because StarStatsXY is defined as an extension on Map<num, num>.


Usage Examples

Math Utilities:
import 'package:starfruit/starfruit.dart';

main() {
  /Round to 2 decimal places
  //Ceiling and flooring to decimal places is also available
  print('Round 3.5634 to 2 decimal places:');
  print(mathUtils.roundToDouble(3.5634, 2));
  print('');

  //Power of two check
  print('Is 8 a power of two?');
  print(mathUtils.isPowerOfTwo(8));
  print('');

  //Calculate log base 2 of 8
  print('Calculate log base 2 of 8:');
  print(mathUtils.log(2, 8));
  print('');

  //double isInteger check
  print('Is 6.0 an integer?');
  print(mathUtils.isMathematicalInteger(6.0));
  print('');

  //Calculate 5!
  print('Calculate 5 factorial:');
  print(mathUtils.factorial(5));
  print('');

  //Check if 2 is within 3 of 5
  print('Is 2 within 3 of 5?');
  print(mathUtils.fuzzyEquals(2, 5, 3));
  print('');

  //Check if 7919 is a prime number
  print('Is 7919 prime?');
  print(mathUtils.isPrime(7919));
  print('');

  //LCM of 2 and 7
  print('Calculate LCM of 2 and 7:');
  print(mathUtils.lcm(2, 7));
  print('');

  //sinh of 1 radian
  print('Calculate sinh of 1 radian:');
  print(mathUtils.sinh(1));
  print('');

  //mean of 3 and 7
  print('Calculate mean of 3 and 7:');
  print(mathUtils.mean(3,7));
  print('');

  //nCr where n = 5 and r = 2
  print('Calculate the binomial coefficient of 2 and 5:');
  print(mathUtils.combinationsOf(5, 2));
  print('');

  //nPr where n = 5 and r = 2
  print('Calculate the permutations of 5 and 2:');
  print(mathUtils.permutationsOf(5, 2));
  print('');
}
Collection Utilities:
import 'package:starfruit/starfruit.dart';

main() {
  //Separate List into chunks
  print("Separate List into chunks of 4:");
  print(cUtils.chunks([1,2,3,4,5,6,7,8], 4));
  print("");

  //Collapse List<List<Object>> into just List<Object>
  print("Collapse List<List> into List:");
  print(cUtils.collapse( [[1,2,3],[4,5,6,7,8]] ));
  print("");

  //Get every nth object of list
  print("Get every 4th object:");
  print(cUtils.nth([1,2,3,4,5,6,7,8], 4));
  print("");

  //Get every n random elements of list
  print("Get 5 random elements:");
  print(cUtils.random([1,2,3,4,5,6,7,8], 5));
  print("");

  //Flip keys and values of a map
  print("Flip keys and values of a map:");
  print(cUtils.flip({1:0, 2:8, 3:4, 0:5}));
  print("");

  //Zip two Lists into a map
  print("Zip two lists into a map:");
  print(cUtils.zip([1,2,3,4], [5,6,7,8]));
  print("");

  //Unzip a map into two lists
  print("Unzip a map into two lists:");
  print(cUtils.unzip({0:1, 8:2, 4:3, 5:0}));
  print("");
}
Stats Utilities:
import 'package:starfruit/starfruit.dart';

main() {
  var stats = [1,3,4,5,12,3,4,67,8,0,22];

  //median
  print("Calculate the median:");
  print(stats.median);
  print("");

  //mean
  print("Calculate the mean:");
  print(stats.mean);
  print("");

  //mode
  print("Calculate the mode:");
  print(stats.mode);
  print("");

  //variance
  print('Calculate the variance:');
  print(stats.variance);
  print("");

  //standard deviation
  print("Calculate the standard deviation:");
  print(stats.stdDev);
  print("");

  //cardinality; number of unique elements
  print("Calculate the cardinality:");
  print(stats.cardinality);
  print("");

  //7 greatest elements
  print("Return the 7 greatest elements:");
  print(stats.topElements(7));
  print("");
}
XY (Paired) Stats Utilities:
import 'package:starfruit/starfruit.dart';

main() {
  var xystats = {2:3, 7:4, 4:6, 8:9, 1:2, 3:5, 11:14, 12:18};

  //Get correlation coefficient
  print("Calculate correlation coefficient:");
  print(xystats.corCoefficient);
  print("");

  //Get determination coefficent
  print("Calculate determination coefficient:");
  print(xystats.detCoefficient);
  print("");

  //Get adjusted determination coefficient
  print("Calculate adj. determination coefficient:");
  print(xystats.adjDetCoefficient);
  print("");

  //Get linear regression line
  print("Calculate linear regression line in form y = mx + b:");
  var lr = xystats.linReg;
  print("y = ${lr[0]}x + ${lr[1]}");
  print("");

  //Get quadratic regression line
  print("Calculate quadratic regression line in form y = ax^2 + bx + c:");
  var qdr = xystats.quadReg;
  print("y = ${qdr[0]}x^2 + ${qdr[1]}x + ${qdr[2]}");
  print("");

  //Get cubic regression line
  print("Calculate cubic regression line in form y = ax^3 + bx^2 + cx + d:");
  var cr = xystats.cubicReg;
  print("y = ${cr[0]}x^3 + ${cr[1]}x^2 + ${cr[2]}x + ${cr[3]}");
  print("");

  //Get quartic regression line
  print("Calculate quartic regression line in form y = ax^4 + bx^3 + cx^2 + dx + e:");
  var qrr = xystats.quarReg;
  print("y = ${qrr[0]}x^4 + ${qrr[1]}x^3 + ${qrr[2]}x^2 + ${qrr[3]}x + ${qrr[4]}");
  print("");
}

Features and bugs

Please file feature requests and bugs at the issue tracker.


Pub License Commits

Starfruit, a set of Dart utility libraries.
©2020 Aditya Kishore
Licensed under the MPL 2.0 (See LICENSE)

Libraries

starfruit
Starfruit is a set of utility libraries for Dart, inspired by and partially ported from Google's Guava (for Java). Currently, math and statistics libraries have been provided, with support for more planned in the near future.