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Linear Programming using GLPK and comfort-array Simple interface to linear programming functions provided by GLPK using the flexible Array shape framework from comfort-array. E.g. you can use Shape.Tuple to convert safely between nested tuples and arrays with the same number of elements.

type X = Shape.Element
type PairShape = Shape.NestedTuple Shape.TupleIndex (X,X)

case Shape.indexTupleFromShape (Shape.static :: PairShape) of
(posIx,negIx) ->
case mapSnd (mapSnd Array.toTuple) <$>
LP.simplex [] [[1.*posIx, (-1).*negIx] ==. 314]
(LP.Minimize,
Array.fromTuple (23,42) :: Array PairShape Double)
of
(Right (LP.Optimal, (absol, (pos, neg)))) ->
printf "absol %f,  pos %f, neg %f\n" absol pos neg
_ -> fail "GLPK solver failed"

Alternatives: coinor-clp, hmatrix-glpk, glpk-hs

package comfort-graph

Graph structure with type parameters for nodes and edges This graph structure is based on Data.Map and allows any Ord type for nodes and allows directed, undirected and more edge types. There is no need to map nodes to integer numbers. This makes handling in applications much more comfortable, thus the package name. This is especially useful for applications where there is no simple mapping of your node identifiers to integers or where the set of nodes is extended or reduced frequently. However, this flexibility comes with some costs. Since the structure is based on Data.Map.Maps, for efficient computing the node type should support fast comparison. The edge type can be freely chosen. This allows great flexibility but it is a bit more cumbersome to do in Haskell 98. Examples of edge types:
- DirEdge: Edges in a directed graph
- UndirEdge: Edges in an undirected graph
- EitherEdge: For graphs containing both directed and undirected edges
- You may define an edge type with an additional identifier in order to support multiple edges between the same pair of nodes.
- Using type functions with the node type as parameter you may even define an edge type for nodes from a Cartesian product, where only "horizontal" and "vertical" edges are allowed.
For examples see the linear-circuit package and its tests. The ResistorCube test demonstrates non-integer node types and the Tree test demonstrates multigraphs. Another application is cabal-sort. Currently the package does not contain any advanced algorithm, just the data structure and some manipulation functions. The package is plain Haskell 98. Related packages:
- fgl: standard package for graph processing with many graph algorithms but cumbersome data structure with Int numbered nodes
package commonmark-pandoc

Bridge between commonmark and pandoc AST. This library provides typeclasses for rendering commonmark to Pandoc types.
package commutative

Commutative binary operations. Please see the README on Github at https://github.com/athanclark/commutative#readme
package compactmap

A read-only memory-efficient key-value store. A read-only key-value store that uses a sorted vector internally
package companion

A Haskell library to provide companion threads. Please see the README on GitHub at https://github.com/commercialhaskell/companion#readme
package compensated

Compensated floating-point arithmetic This package provides compensated floating point arithmetic.
package compiler-warnings

Parser for common compiler warning formats Parser for common compiler warning formats
package composable-associations

Types and helpers for composing types into a single larger key-value type. A library providing generic types and helpers for composing types together into a a single key-value type. This is useful when a normalized data model has a denormalized serialization format. Using this libraries types and functions you build compose your data into the denormalized key-value format needed for serialization. Other libraries provide concrete implementations for a given serialization format.
package composition

Combinators for unorthodox function composition Combinators for unorthodox function composition

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