Use strings instead of enums for eigenvalues order specification - gsl-shell.git - gsl-shell

diff --git a/doc/user-manual/eigen.rst b/doc/user-manual/eigen.rst
index d696882a..e1098f77 100644
--- a/doc/user-manual/eigen.rst
+++ b/doc/user-manual/eigen.rst

@@ -19,20 +19,20 @@ Real Symmetric Matrices

This function computes the eigenvalues and eigenvectors of the real symmetric matrix A. The default ordering of the eigenvalues and eigenvectors is descending order in numerical value.

You can however choose from the following sorting shemes for the eigenvalues:

- `eigen.SORT_VAL_DESC`

+ 'desc'

descending order in numerical value

- `eigen.SORT_VAL_ASC`

+ 'asc'

ascending order in numerical value

- `eigen.SORT_ABS_ASC`

+ 'abs_asc'

ascending order in magnitude

- `eigen.SORT_ABS_DESC`

+ 'abs_desc'

descending order in magnitude

- `eigen.SORT_NONE`

+ 'none'

eigenvalue sorting

The function returns::

- eval, evec = symm(A, eigen.SORT_ABS_ASC)

+ eval, evec = symm(A, 'abs_asc')

while the first eigenvalue correpsonds to the first eigenvector stored in the first column of the eigenvectors matrix.

For real symmetric matrices, the library uses the symmetric bidiagonalization and QR reduction method.

@@ -53,7 +53,7 @@ Real Nonsymmetric Matrices

This function computes eigenvalues and right eigenvectors of the n-by-n real nonsymmetric matrix A.

The computed eigenvectors are normalized to have unit magnitude. On output, the upper portion of A contains the Schur form T::

- eval, evec, A = non_symm(A, eigen.SORT_ABS_ASC)

+ eval, evec, A = non_symm(A, 'abs_asc')

Complex Hermitian Matrices

diff --git a/eigen.lua b/eigen.lua
index 77ad3fb2..ab30a52a 100644
--- a/eigen.lua
+++ b/eigen.lua

@@ -326,12 +326,21 @@ gsl_eigen_invert_jacobi(const gsl_matrix * matrix,

-------------------------------------------------------------------------------

eigen = {}

---Definitions of the sorting order of the eigenvalues

-eigen.SORT_VAL_DESC = gsl.GSL_EIGEN_SORT_VAL_DESC

-eigen.SORT_VAL_ASC = gsl.GSL_EIGEN_SORT_VAL_ASC

-eigen.SORT_ABS_ASC = gsl.GSL_EIGEN_SORT_ABS_ASC

-eigen.SORT_ABS_DESC = gsl.GSL_EIGEN_SORT_ABS_DESC

-eigen.SORT_NONE = gsl.GSL_EIGEN_SORT_NONE

+order_lookup = {

+ asc = gsl.GSL_EIGEN_SORT_VAL_ASC,

+ desc = gsl.GSL_EIGEN_SORT_VAL_DESC,

+ abs_asc = gsl.GSL_EIGEN_SORT_ABS_ASC,

+ abs_desc = gsl.GSL_EIGEN_SORT_ABS_DESC,

+ none = gsl.GSL_EIGEN_SORT_NONE

+}

+

+local SORT_NONE = gsl.GSL_EIGEN_SORT_NONE

+

+local function get_order(order)

+ local sel = order and order_lookup[order] or gsl.GSL_EIGEN_SORT_VAL_DESC

+ if not sel then error('invalid order specification: '..order, 3) end

+ return sel

+end

--Calculates the eigenvalues/eigenvectors of the symmetric matrix m

--the order can be used to determine the sorting of the eigenvalues according to their value

@@ -341,14 +350,14 @@ function eigen.symm(m, order)

local eval = matrix.alloc(size, 1)

local evec = matrix.alloc (size, size)

local xeval = gsl.gsl_matrix_column(eval, 0)

- order = order or eigen.SORT_VAL_DESC

+ local order_sel = get_order(order)

local w = gsl.gsl_eigen_symmv_alloc (size)

gsl_check(gsl.gsl_eigen_symmv (A, xeval, evec, w))

gsl.gsl_eigen_symmv_free (w)

- if order ~= eigen.SORT_NONE then

- gsl.gsl_eigen_symmv_sort (xeval, evec, order)

+ if order_sel ~= SORT_NONE then

+ gsl.gsl_eigen_symmv_sort (xeval, evec, order_sel)

end

return eval,evec

@@ -362,14 +371,14 @@ function eigen.non_symm(m, order)

local eval = matrix.calloc(size, 1)

local evec = matrix.calloc (size, size)

local xeval = gsl.gsl_matrix_complex_column(eval, 0)

- order = order or eigen.SORT_VAL_DESC

+ local order_sel = get_order(order)

local w = gsl.gsl_eigen_nonsymmv_alloc (size)

gsl_check(gsl.gsl_eigen_nonsymmv (A, xeval, evec, w))

gsl.gsl_eigen_nonsymmv_free (w)

- if order ~= eigen.SORT_NONE then

- gsl.gsl_eigen_nonsymmv_sort (xeval, evec, order)

+ if order_sel ~= SORT_NONE then

+ gsl.gsl_eigen_nonsymmv_sort (xeval, evec, order_sel)

end

return eval,evec

@@ -381,14 +390,14 @@ function eigen.herm(m, order, eigenvalues_only)

local eval = matrix.alloc(size, 1)

local xeval = gsl.gsl_matrix_column(eval, 0)

local evec = matrix.calloc (size, size)

- order = order or eigen.SORT_VAL_DESC

+ local order_sel = get_order(order)

local w = gsl.gsl_eigen_hermv_alloc (size)

gsl_check(gsl.gsl_eigen_hermv(A, xeval, evec, w))

gsl.gsl_eigen_hermv_free (w)

- if order ~= eigen.SORT_NONE then

- gsl.gsl_eigen_hermv_sort (xeval, evec, order)

+ if order_sel ~= SORT_NONE then

+ gsl.gsl_eigen_hermv_sort (xeval, evec, order_sel)

end

return eval,evec

@@ -402,14 +411,14 @@ function eigen.gensymm(a, b)

local eval = matrix.alloc(size, 1)

local xeval = gsl.gsl_matrix_column(eval, 0)

local evec = matrix.alloc (size, size)

- order = order or eigen.SORT_VAL_DESC

+ local order_sel = get_order(order)

local w = gsl.gsl_eigen_gensymmv_alloc (size)

gsl_check(gsl.gsl_eigen_gensymmv(A,B, xeval, evec, w))

gsl.gsl_eigen_gensymmv_free (w)

- if order ~= eigen.SORT_NONE then

- gsl.gsl_eigen_gensymmv_sort (xeval, evec, order)

+ if order_sel ~= SORT_NONE then

+ gsl.gsl_eigen_gensymmv_sort (xeval, evec, order_sel)

end

return eval,evec

@@ -422,14 +431,14 @@ function eigen.genherm(a, b)

local eval = matrix.alloc(size, 1)

local xeval = gsl.gsl_matrix_column(eval, 0)

local evec = matrix.calloc (size, size)

- order = order or eigen.SORT_VAL_DESC

+ local order_sel = get_order(order)

local w = gsl.gsl_eigen_genhermv_alloc (size)

gsl_check(gsl.gsl_eigen_genhermv(A,B, xeval, evec, w))

gsl.gsl_eigen_genhermv_free (w)

- if order ~= eigen.SORT_NONE then

- gsl.gsl_eigen_genhermv_sort (xeval, evec, order)

+ if order_sel ~= SORT_NONE then

+ gsl.gsl_eigen_genhermv_sort (xeval, evec, order_sel)

end

return eval,evec

@@ -446,14 +455,14 @@ function eigen.gen(a, b)

local beta_vec = gsl.gsl_matrix_column(beta, 0)

local evec = matrix.calloc (size, size)

- order = order or eigen.SORT_VAL_DESC

+ local order_sel = get_order(order)

local w = gsl.gsl_eigen_genv_alloc (size)

gsl_check(gsl.gsl_eigen_genv(A,B, alpha_vec, beta_vec, evec, w))

gsl.gsl_eigen_genv_free (w)

- if order ~= eigen.SORT_NONE then

- gsl.gsl_eigen_genv_sort (alpha_vec, beta_vec, evec, order)

+ if order_sel ~= SORT_NONE then

+ gsl.gsl_eigen_genv_sort (alpha_vec, beta_vec, evec, order_sel)

end

return alpha, beta, evec