GSL-OCaml - GSL-Bindings for OCaml

This library was written by Olivier Andrieu.
This version (gsl-ocaml) contains patches by Markus
that may be merged into the original distribution
in the future.

GSL-OCaml is an interface to the GSL
(GNU scientific library) for the OCaml-language.


The platform must not align doubles on double-word addresses, i.e. the C-macro
ARCH_ALIGN_DOUBLE must be undefined in the OCaml C-configuration header in


$ ./configure
$ make
$ make install


Check the GSL manual
to learn more about the GNU Scientific Library.

You can browse the OCaml module interfaces as ocamldoc-generated
HTML files in directory API.docdir after building the
documentation with make doc. It is also available

Usage Hints

Vectors and Matrices

There are several data types for handling vectors and matrices.

  • Modules Gsl.Vector, Gsl.Vector.Single, Gsl.Vector_complex,
    Gsl.Vector_complex.Single, and the corresponding matrix modules use
    bigarrays with single or double precision and real or complex values.

  • Modules Gsl.Vector_flat, Gsl.Vector_complex_flat, and the corresponding
    matrix modules use a record wrapping a regular OCaml float array. This is
    the equivalent of the gsl_vector and gsl_matrix structs in GSL.

  • Module Gsl.Vectmat defines a sum type with polymorphic variants
    that regroups these two representations. For instance:

    Gsl.Vectmat.v_add (`V v1) (`VF v2)

    adds a vector in an OCaml array to a bigarray.

  • Modules Gsl.Blas Gsl.Blas_flat and Gsl.Blas_gen provide a (quite
    incomplete) interface to CBLAS for these types.


Errors in GSL functions are reported as exceptions:

Gsl.Error.Gsl_exn (errno, msg)

You have to call Gsl.Error.init () to initialize error reporting. Otherwise,
the default GSL error handler is used and aborts the program, leaving a core
dump (not so helpful with OCaml).

If a callback (for minimizers, solvers, etc.) raises an exception, gsl-ocaml
either returns GSL_FAILURE or NaN to GSL depending on the type of callback.
In either case the original OCaml exception is not propagated. The GSL
function will either return normally (but probably with values containing
NaNs somewhere) or raise a Gsl_exn exception.