Introduce public method eigenvalues

SWITCHING_TO_NEW_INTERFACE.md

@@ -128,8 +128,9 @@ the user application):
 
 
 6. do the desired task with the *ELPA* library, which could be
-   a) e%eigenvectors                  ! solve EV problem with solver as set by "set" method; returns eigenvalues AND eigenvectors
+   a) e%eigenvectors                  ! solve EV problem with solver as set by "set" method; computes eigenvalues AND eigenvectors
                                       ! (replaces a) and b) from legacy API)
+   b) e%eigenvalues                   ! solve EV problem with solver as set by "set" method; computes eigenvalues only
    b) e%solve_tridi                   ! solve problem with tridiagonal matrix  (replacement for c) from legacy API)
    c) e%choleksy                      ! do a cholesky decomposition (replaces  d) from legacy API)
    d) e%invert_tridiagonal            ! invert triangular matrix (replaces  e) from legacy API)

USERS_GUIDE.md

@@ -59,7 +59,6 @@ Using *ELPA* with the latest API is done in the following steps
        of the ELPA library has been build with GPU support enables
      - "timings" can be either 0 or 1, switches time measurements off or on
      - "debug" can be either 0 or 1, switches detailed debug messages off/on
-     - "eigenvalues_only" can be either 0 or 1. In case of 1 only compute the eigenvalues
 
 - call ELPA-type function solve or others
 
@@ -67,6 +66,8 @@ Using *ELPA* with the latest API is done in the following steps
 
     - "eigenvectors" solves the eigenvalue problem for single/double real/complex valued matrices and
                      returns the eigenvalues AND eigenvectors
+    - "eigenvalues" solves the eigenvalue problem for single/double real/complex valued matrices and
+                     returns the eigenvalues
     - "hermetian_multipy" computes C = A^T * B (real) or C = A^H * B (complex) for single/double
       real/complex matrices
     - "cholesky" does a cholesky factorization for a single/double real/complex matrix

src/elpa1/elpa1_template.X90

@@ -102,8 +102,6 @@ function elpa_solve_evp_&
    logical                                         :: useGPU
    logical                                         :: success
 
-   logical                                         :: solve_eigenvectors
-
    logical                                         :: do_useGPU
    integer(kind=ik)                                :: numberOfGPUDevices
 
@@ -114,7 +112,6 @@ function elpa_solve_evp_&
    character(200)                                  :: errorMessage
    integer(kind=ik)                                :: na, nev, lda, ldq, nblk, matrixCols, &
                                                       mpi_comm_rows, mpi_comm_cols, mpi_comm_all
-   integer(kind=ik)                                :: eigenvalues_only
 
    call obj%timer%start("elpa_solve_evp_&
    &MATH_DATATYPE&
@@ -124,9 +121,9 @@ function elpa_solve_evp_&
 
 
    if (present(q)) then
-     solve_eigenvectors =.true.
+     obj%eigenvalues_only = .false.
    else
-     solve_eigenvectors = .false.
+     obj%eigenvalues_only = .true.
    endif
 
    na         = obj%na
@@ -206,7 +203,7 @@ function elpa_solve_evp_&
    endif
 
    ! allocate a dummy q_intern, if eigenvectors should not be commputed and thus q is NOT present
-   if ((solve_eigenvectors)) then
+   if (.not.(obj%eigenvalues_only)) then
      q_actual => q(1:obj%local_nrows,1:obj%local_ncols)
    else
      allocate(q_dummy(obj%local_nrows,obj%local_ncols))
@@ -261,15 +258,14 @@ function elpa_solve_evp_&
    call obj%timer%stop("solve")
    if (.not.(success)) return
 
-   call obj%get("eigenvalues_only",eigenvalues_only)
-   if (eigenvalues_only .eq. 1) then
+   if (obj%eigenvalues_only) then
      return
    endif
 
-   if ((solve_eigenvectors) ) then
+   if (.not.(obj%eigenvalues_only) ) then
     ! q must be given thats why from here on we can use q and not q_actual
 #if COMPLEXCASE == 1
-     ql(1:l_rows,1:l_cols_nev) = q_real(1:l_rows,1:l_cols_nev)
+     q(1:l_rows,1:l_cols_nev) = q_real(1:l_rows,1:l_cols_nev)
 #endif
 
      call obj%timer%start("back")
@@ -279,7 +275,7 @@ function elpa_solve_evp_&
      &PRECISION&
      & (obj, na, nev, a, lda, tau, q, ldq, nblk, matrixCols, mpi_comm_rows, mpi_comm_cols, do_useGPU)
      call obj%timer%stop("back")
-   endif ! .not.solve_eigenvectors
+   endif ! .not.(obj%eigenvalues_only
 
 #if COMPLEXCASE == 1
     deallocate(q_real, stat=istat, errmsg=errorMessage)
@@ -303,7 +299,7 @@ function elpa_solve_evp_&
      stop 1
    endif
 
-   if (.not.(solve_eigenvectors)) then
+   if (obj%eigenvalues_only) then
      deallocate(q_dummy, stat=istat, errmsg=errorMessage)
      if (istat .ne. 0) then
        print *,"solve_evp_&

src/elpa2/elpa2_template.X90

@@ -100,7 +100,7 @@
    integer(kind=c_intptr_t)                  :: tmat_dev, q_dev, a_dev
 
    integer(kind=c_int)                       :: i
-   logical                                   :: success, successCUDA, solve_eigenvectors
+   logical                                   :: success, successCUDA
    logical                                   :: wantDebug
    integer(kind=c_int)                       :: istat, gpu, debug, qr
    character(200)                            :: errorMessage
@@ -112,7 +112,6 @@
                                                                    &MATH_DATATYPE
     integer(kind=ik)                         :: na, nev, lda, ldq, nblk, matrixCols, &
                                                 mpi_comm_rows, mpi_comm_cols, mpi_comm_all
-    integer(kind=ik)                         :: eigenvalues_only
 
     call obj%timer%start("elpa_solve_evp_&
     &MATH_DATATYPE&
@@ -121,9 +120,9 @@
     &")
 
     if (present(q)) then
-      solve_eigenvectors = .true.
+      obj%eigenvalues_only = .false.
     else
-      solve_eigenvectors = .false.
+      obj%eigenvalues_only = .true.
     endif
 
     na         = obj%na
@@ -264,7 +263,7 @@
     call obj%timer%start("bandred")
 
 
-    if (solve_eigenvectors) then
+    if (.not. obj%eigenvalues_only) then
       q_actual => q(1:obj%local_nrows,1:obj%local_ncols)
     else
      allocate(q_dummy(1:obj%local_nrows,1:obj%local_ncols))
@@ -392,12 +391,11 @@
        stop 1
      endif
 
-     call obj%get("eigenvalues_only",eigenvalues_only)
-     if (eigenvalues_only .eq. 1) then
+     if (obj%eigenvalues_only) then
        return
      endif
 
-     if (solve_eigenvectors) then
+     if (.not. obj%eigenvalues_only) then
 #if COMPLEXCASE == 1
        ! q must be given thats why from here on we can use q and not q_actual
 
@@ -471,9 +469,9 @@
         endif
         endif
        call obj%timer%stop("trans_ev_to_full")
-     endif ! solve_eigenvectors
+     endif ! .not. obj%eigenvalue_only
 
-     if (.not.(solve_eigenvectors)) then
+     if (obj%eigenvalues_only) then
        deallocate(q_dummy, stat=istat, errmsg=errorMessage)
        if (istat .ne. 0) then
          print *,"solve_evp_&

src/elpa_abstract_impl.F90

@@ -77,6 +77,7 @@ module elpa_abstract_impl
 #endif
     type(c_ptr)         :: index = C_NULL_PTR
 
+    logical             :: eigenvalues_only
     contains
       ! set private fields in the index
       generic, public :: set_private => &

src/elpa_index.c

@@ -113,9 +113,10 @@ static int elpa_double_value_to_string(char *name, double value, const char **st
                 BASE_ENTRY(option_name, option_description, 0, 0, 0), \
         }
 
-#define PRIVATE_INT_ENTRY(option_name, option_description) \
+#define PRIVATE_INT_ENTRY(option_name, default) \
         { \
-                BASE_ENTRY(option_name, option_description, 0, 0, 1), \
+                BASE_ENTRY(option_name, NULL, 0, 0, 1), \
+		.default_value = default, \
         }
 
 static const elpa_index_int_entry_t int_entries[] = {
@@ -145,7 +146,7 @@ static const elpa_index_int_entry_t int_entries[] = {
         BOOL_ENTRY("timings", "Enable time measurement", 0),
         BOOL_ENTRY("debug", "Emit verbose debugging messages", 0),
         BOOL_ENTRY("print_flops", "Print FLOP rates on task 0", 0),
-        BOOL_ENTRY("eigenvalues_only", "Only compute the eigenvalues and return", 0),
+        PRIVATE_INT_ENTRY("eigenvalues_only", 0),
 };
 
 #define READONLY_DOUBLE_ENTRY(option_name, option_description) \