psblas3:

base/modules/psb_c_base_mat_mod.f90
 base/modules/psb_c_comm_mod.f90
 base/modules/psb_c_mat_mod.f90
 base/modules/psb_d_base_mat_mod.f90
 base/modules/psb_d_comm_mod.f90
 base/modules/psb_d_mat_mod.f90
 base/modules/psb_s_base_mat_mod.f90
 base/modules/psb_s_comm_mod.f90
 base/modules/psb_s_mat_mod.f90
 base/modules/psb_z_base_mat_mod.f90
 base/modules/psb_z_comm_mod.f90
 base/modules/psb_z_mat_mod.f90
 base/serial/impl/psb_c_base_mat_impl.F90
 base/serial/impl/psb_c_coo_impl.f90
 base/serial/impl/psb_d_base_mat_impl.F90
 base/serial/impl/psb_d_coo_impl.f90
 base/serial/impl/psb_s_base_mat_impl.F90
 base/serial/impl/psb_s_coo_impl.f90
 base/serial/impl/psb_z_base_mat_impl.F90
 base/serial/impl/psb_z_coo_impl.f90

Add clean_zeros method.

base/modules/psb_c_base_mat_mod.f90

@@ -42,7 +42,7 @@ module psb_c_base_mat_mod
   !! The psb_c_base_sparse_mat type, extending psb_base_sparse_mat,
   !! defines a middle level  complex(psb_spk_) sparse matrix object.
   !! This class object itself does not have any additional members
-  !! with respect to those of the base class. No methods can be fully
+  !! with respect to those of the base class. Most methods cannot be fully
   !! implemented at this level, but we can define the interface for the
   !! computational methods requiring the knowledge of the underlying
   !! field, such as the matrix-vector product; this interface is defined,
@@ -78,6 +78,7 @@ module psb_c_base_mat_mod
     procedure, pass(a) :: mold          => psb_c_base_mold 
     procedure, pass(a) :: clone         => psb_c_base_clone
     procedure, pass(a) :: make_nonunit  => psb_c_base_make_nonunit
+    procedure, pass(a) :: clean_zeros   => psb_c_base_clean_zeros
     
     !
     ! Transpose methods: defined here but not implemented. 
@@ -165,6 +166,7 @@ module psb_c_base_mat_mod
     procedure, pass(a) :: get_nz_row   => psb_c_coo_get_nz_row
     procedure, pass(a) :: fix          => psb_c_fix_coo
     procedure, pass(a) :: trim         => psb_c_coo_trim
+    procedure, pass(a) :: clean_zeros  => psb_c_coo_clean_zeros
     procedure, pass(a) :: print        => psb_c_coo_print
     procedure, pass(a) :: free         => c_coo_free
     procedure, pass(a) :: mold         => psb_c_coo_mold
@@ -701,6 +703,18 @@ module psb_c_base_mat_mod
       integer(psb_ipk_), intent(out)            :: info
     end subroutine psb_c_base_mv_from_fmt
   end interface
+  !
+  !> 
+  !! \memberof  psb_c_base_sparse_mat
+  !! \see psb_c_base_mat_mod::psb_c_base_clean_zeros
+  !
+  interface
+    subroutine  psb_c_base_clean_zeros(a, info)
+      import :: psb_ipk_, psb_c_base_sparse_mat
+      class(psb_c_base_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)              :: info
+    end subroutine psb_c_base_clean_zeros
+  end interface
   
   !
   !> Function  transp:
@@ -1239,6 +1253,18 @@ module psb_c_base_mat_mod
       class(psb_c_coo_sparse_mat), intent(inout) :: a
     end subroutine psb_c_coo_trim
   end interface
+  !
+  !> 
+  !! \memberof  psb_c_coo_sparse_mat
+  !! \see psb_c_base_mat_mod::psb_c_base_clean_zeros
+  !
+  interface
+    subroutine  psb_c_coo_clean_zeros(a,info)
+      import :: psb_ipk_, psb_c_coo_sparse_mat
+      class(psb_c_coo_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)             :: info
+    end subroutine psb_c_coo_clean_zeros
+  end interface
   
   !
   !> 

base/modules/psb_c_mat_mod.f90

@@ -133,6 +133,7 @@ module psb_c_mat_mod
     procedure, pass(a) :: m_csclip    => psb_c_csclip
     procedure, pass(a) :: b_csclip    => psb_c_b_csclip
     generic, public    :: csclip      => b_csclip, m_csclip
+    procedure, pass(a) :: clean_zeros => psb_c_clean_zeros
     procedure, pass(a) :: reall       => psb_c_reallocate_nz
     procedure, pass(a) :: get_neigh   => psb_c_get_neigh
     procedure, pass(a) :: reinit      => psb_c_reinit
@@ -1279,7 +1280,15 @@ contains
 
   end function psb_c_get_nz_row
 
+  subroutine psb_c_clean_zeros(a,info)
+    implicit none 
+    integer(psb_ipk_), intent(out)        :: info
+    class(psb_cspmat_type), intent(inout) :: a
+
+    info = 0 
+    if (allocated(a%a)) call a%a%clean_zeros(info)
 
+  end subroutine psb_c_clean_zeros
 
 
 end module psb_c_mat_mod

base/modules/psb_d_base_mat_mod.f90

@@ -42,7 +42,7 @@ module psb_d_base_mat_mod
   !! The psb_d_base_sparse_mat type, extending psb_base_sparse_mat,
   !! defines a middle level  real(psb_dpk_) sparse matrix object.
   !! This class object itself does not have any additional members
-  !! with respect to those of the base class. No methods can be fully
+  !! with respect to those of the base class. Most methods cannot be fully
   !! implemented at this level, but we can define the interface for the
   !! computational methods requiring the knowledge of the underlying
   !! field, such as the matrix-vector product; this interface is defined,
@@ -78,6 +78,7 @@ module psb_d_base_mat_mod
     procedure, pass(a) :: mold          => psb_d_base_mold 
     procedure, pass(a) :: clone         => psb_d_base_clone
     procedure, pass(a) :: make_nonunit  => psb_d_base_make_nonunit
+    procedure, pass(a) :: clean_zeros   => psb_d_base_clean_zeros
     
     !
     ! Transpose methods: defined here but not implemented. 
@@ -165,6 +166,7 @@ module psb_d_base_mat_mod
     procedure, pass(a) :: get_nz_row   => psb_d_coo_get_nz_row
     procedure, pass(a) :: fix          => psb_d_fix_coo
     procedure, pass(a) :: trim         => psb_d_coo_trim
+    procedure, pass(a) :: clean_zeros  => psb_d_coo_clean_zeros
     procedure, pass(a) :: print        => psb_d_coo_print
     procedure, pass(a) :: free         => d_coo_free
     procedure, pass(a) :: mold         => psb_d_coo_mold
@@ -701,6 +703,18 @@ module psb_d_base_mat_mod
       integer(psb_ipk_), intent(out)            :: info
     end subroutine psb_d_base_mv_from_fmt
   end interface
+  !
+  !> 
+  !! \memberof  psb_d_base_sparse_mat
+  !! \see psb_d_base_mat_mod::psb_d_base_clean_zeros
+  !
+  interface
+    subroutine  psb_d_base_clean_zeros(a, info)
+      import :: psb_ipk_, psb_d_base_sparse_mat
+      class(psb_d_base_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)              :: info
+    end subroutine psb_d_base_clean_zeros
+  end interface
   
   !
   !> Function  transp:
@@ -1239,6 +1253,18 @@ module psb_d_base_mat_mod
       class(psb_d_coo_sparse_mat), intent(inout) :: a
     end subroutine psb_d_coo_trim
   end interface
+  !
+  !> 
+  !! \memberof  psb_d_coo_sparse_mat
+  !! \see psb_d_base_mat_mod::psb_d_base_clean_zeros
+  !
+  interface
+    subroutine  psb_d_coo_clean_zeros(a,info)
+      import :: psb_ipk_, psb_d_coo_sparse_mat
+      class(psb_d_coo_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)             :: info
+    end subroutine psb_d_coo_clean_zeros
+  end interface
   
   !
   !> 

base/modules/psb_d_mat_mod.f90

@@ -133,6 +133,7 @@ module psb_d_mat_mod
     procedure, pass(a) :: m_csclip    => psb_d_csclip
     procedure, pass(a) :: b_csclip    => psb_d_b_csclip
     generic, public    :: csclip      => b_csclip, m_csclip
+    procedure, pass(a) :: clean_zeros => psb_d_clean_zeros
     procedure, pass(a) :: reall       => psb_d_reallocate_nz
     procedure, pass(a) :: get_neigh   => psb_d_get_neigh
     procedure, pass(a) :: reinit      => psb_d_reinit
@@ -1279,7 +1280,15 @@ contains
 
   end function psb_d_get_nz_row
 
+  subroutine psb_d_clean_zeros(a,info)
+    implicit none 
+    integer(psb_ipk_), intent(out)        :: info
+    class(psb_dspmat_type), intent(inout) :: a
+
+    info = 0 
+    if (allocated(a%a)) call a%a%clean_zeros(info)
 
+  end subroutine psb_d_clean_zeros
 
 
 end module psb_d_mat_mod

base/modules/psb_s_base_mat_mod.f90

@@ -42,7 +42,7 @@ module psb_s_base_mat_mod
   !! The psb_s_base_sparse_mat type, extending psb_base_sparse_mat,
   !! defines a middle level  real(psb_spk_) sparse matrix object.
   !! This class object itself does not have any additional members
-  !! with respect to those of the base class. No methods can be fully
+  !! with respect to those of the base class. Most methods cannot be fully
   !! implemented at this level, but we can define the interface for the
   !! computational methods requiring the knowledge of the underlying
   !! field, such as the matrix-vector product; this interface is defined,
@@ -78,6 +78,7 @@ module psb_s_base_mat_mod
     procedure, pass(a) :: mold          => psb_s_base_mold 
     procedure, pass(a) :: clone         => psb_s_base_clone
     procedure, pass(a) :: make_nonunit  => psb_s_base_make_nonunit
+    procedure, pass(a) :: clean_zeros   => psb_s_base_clean_zeros
     
     !
     ! Transpose methods: defined here but not implemented. 
@@ -165,6 +166,7 @@ module psb_s_base_mat_mod
     procedure, pass(a) :: get_nz_row   => psb_s_coo_get_nz_row
     procedure, pass(a) :: fix          => psb_s_fix_coo
     procedure, pass(a) :: trim         => psb_s_coo_trim
+    procedure, pass(a) :: clean_zeros  => psb_s_coo_clean_zeros
     procedure, pass(a) :: print        => psb_s_coo_print
     procedure, pass(a) :: free         => s_coo_free
     procedure, pass(a) :: mold         => psb_s_coo_mold
@@ -701,6 +703,18 @@ module psb_s_base_mat_mod
       integer(psb_ipk_), intent(out)            :: info
     end subroutine psb_s_base_mv_from_fmt
   end interface
+  !
+  !> 
+  !! \memberof  psb_s_base_sparse_mat
+  !! \see psb_s_base_mat_mod::psb_s_base_clean_zeros
+  !
+  interface
+    subroutine  psb_s_base_clean_zeros(a, info)
+      import :: psb_ipk_, psb_s_base_sparse_mat
+      class(psb_s_base_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)              :: info
+    end subroutine psb_s_base_clean_zeros
+  end interface
   
   !
   !> Function  transp:
@@ -1239,6 +1253,18 @@ module psb_s_base_mat_mod
       class(psb_s_coo_sparse_mat), intent(inout) :: a
     end subroutine psb_s_coo_trim
   end interface
+  !
+  !> 
+  !! \memberof  psb_s_coo_sparse_mat
+  !! \see psb_s_base_mat_mod::psb_s_base_clean_zeros
+  !
+  interface
+    subroutine  psb_s_coo_clean_zeros(a,info)
+      import :: psb_ipk_, psb_s_coo_sparse_mat
+      class(psb_s_coo_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)             :: info
+    end subroutine psb_s_coo_clean_zeros
+  end interface
   
   !
   !> 

base/modules/psb_s_mat_mod.f90

@@ -133,6 +133,7 @@ module psb_s_mat_mod
     procedure, pass(a) :: m_csclip    => psb_s_csclip
     procedure, pass(a) :: b_csclip    => psb_s_b_csclip
     generic, public    :: csclip      => b_csclip, m_csclip
+    procedure, pass(a) :: clean_zeros => psb_s_clean_zeros
     procedure, pass(a) :: reall       => psb_s_reallocate_nz
     procedure, pass(a) :: get_neigh   => psb_s_get_neigh
     procedure, pass(a) :: reinit      => psb_s_reinit
@@ -1279,7 +1280,15 @@ contains
 
   end function psb_s_get_nz_row
 
+  subroutine psb_s_clean_zeros(a,info)
+    implicit none 
+    integer(psb_ipk_), intent(out)        :: info
+    class(psb_sspmat_type), intent(inout) :: a
+
+    info = 0 
+    if (allocated(a%a)) call a%a%clean_zeros(info)
 
+  end subroutine psb_s_clean_zeros
 
 
 end module psb_s_mat_mod

base/modules/psb_z_base_mat_mod.f90

@@ -42,7 +42,7 @@ module psb_z_base_mat_mod
   !! The psb_z_base_sparse_mat type, extending psb_base_sparse_mat,
   !! defines a middle level  complex(psb_dpk_) sparse matrix object.
   !! This class object itself does not have any additional members
-  !! with respect to those of the base class. No methods can be fully
+  !! with respect to those of the base class. Most methods cannot be fully
   !! implemented at this level, but we can define the interface for the
   !! computational methods requiring the knowledge of the underlying
   !! field, such as the matrix-vector product; this interface is defined,
@@ -78,6 +78,7 @@ module psb_z_base_mat_mod
     procedure, pass(a) :: mold          => psb_z_base_mold 
     procedure, pass(a) :: clone         => psb_z_base_clone
     procedure, pass(a) :: make_nonunit  => psb_z_base_make_nonunit
+    procedure, pass(a) :: clean_zeros   => psb_z_base_clean_zeros
     
     !
     ! Transpose methods: defined here but not implemented. 
@@ -165,6 +166,7 @@ module psb_z_base_mat_mod
     procedure, pass(a) :: get_nz_row   => psb_z_coo_get_nz_row
     procedure, pass(a) :: fix          => psb_z_fix_coo
     procedure, pass(a) :: trim         => psb_z_coo_trim
+    procedure, pass(a) :: clean_zeros  => psb_z_coo_clean_zeros
     procedure, pass(a) :: print        => psb_z_coo_print
     procedure, pass(a) :: free         => z_coo_free
     procedure, pass(a) :: mold         => psb_z_coo_mold
@@ -701,6 +703,18 @@ module psb_z_base_mat_mod
       integer(psb_ipk_), intent(out)            :: info
     end subroutine psb_z_base_mv_from_fmt
   end interface
+  !
+  !> 
+  !! \memberof  psb_z_base_sparse_mat
+  !! \see psb_z_base_mat_mod::psb_z_base_clean_zeros
+  !
+  interface
+    subroutine  psb_z_base_clean_zeros(a, info)
+      import :: psb_ipk_, psb_z_base_sparse_mat
+      class(psb_z_base_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)              :: info
+    end subroutine psb_z_base_clean_zeros
+  end interface
   
   !
   !> Function  transp:
@@ -1239,6 +1253,18 @@ module psb_z_base_mat_mod
       class(psb_z_coo_sparse_mat), intent(inout) :: a
     end subroutine psb_z_coo_trim
   end interface
+  !
+  !> 
+  !! \memberof  psb_z_coo_sparse_mat
+  !! \see psb_z_base_mat_mod::psb_z_base_clean_zeros
+  !
+  interface
+    subroutine  psb_z_coo_clean_zeros(a,info)
+      import :: psb_ipk_, psb_z_coo_sparse_mat
+      class(psb_z_coo_sparse_mat), intent(inout) :: a
+      integer(psb_ipk_), intent(out)             :: info
+    end subroutine psb_z_coo_clean_zeros
+  end interface
   
   !
   !> 

base/modules/psb_z_mat_mod.f90

@@ -133,6 +133,7 @@ module psb_z_mat_mod
     procedure, pass(a) :: m_csclip    => psb_z_csclip
     procedure, pass(a) :: b_csclip    => psb_z_b_csclip
     generic, public    :: csclip      => b_csclip, m_csclip
+    procedure, pass(a) :: clean_zeros => psb_z_clean_zeros
     procedure, pass(a) :: reall       => psb_z_reallocate_nz
     procedure, pass(a) :: get_neigh   => psb_z_get_neigh
     procedure, pass(a) :: reinit      => psb_z_reinit
@@ -1279,7 +1280,15 @@ contains
 
   end function psb_z_get_nz_row
 
+  subroutine psb_z_clean_zeros(a,info)
+    implicit none 
+    integer(psb_ipk_), intent(out)        :: info
+    class(psb_zspmat_type), intent(inout) :: a
+
+    info = 0 
+    if (allocated(a%a)) call a%a%clean_zeros(info)
 
+  end subroutine psb_z_clean_zeros
 
 
 end module psb_z_mat_mod

base/serial/impl/psb_c_base_mat_impl.F90

@@ -318,6 +318,22 @@ subroutine psb_c_base_mv_from_fmt(a,b,info)
 
 end subroutine psb_c_base_mv_from_fmt
 
+subroutine  psb_c_base_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_c_base_mat_mod, psb_protect_name => psb_c_base_clean_zeros
+  implicit none 
+  class(psb_c_base_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_), intent(out)              :: info
+  !
+  type(psb_c_coo_sparse_mat) :: tmpcoo
+
+  call a%mv_to_coo(tmpcoo,info)
+  if (info == 0) call tmpcoo%clean_zeros(info)  
+  if (info == 0) call a%mv_from_coo(tmpcoo,info)
+  
+end subroutine psb_c_base_clean_zeros
+
+
 subroutine psb_c_base_csput_a(nz,ia,ja,val,a,imin,imax,jmin,jmax,info,gtl) 
   use psb_error_mod
   use psb_c_base_mat_mod, psb_protect_name => psb_c_base_csput_a

base/serial/impl/psb_c_coo_impl.f90

@@ -329,6 +329,31 @@ subroutine  psb_c_coo_trim(a)
 
 end subroutine psb_c_coo_trim
 
+subroutine  psb_c_coo_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_c_base_mat_mod, psb_protect_name => psb_c_coo_clean_zeros
+  implicit none 
+  class(psb_c_coo_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_) :: info
+  !
+  integer(psb_ipk_) :: i,j,k, nzin
+
+  info = 0 
+  nzin = a%get_nzeros()
+  j = 0
+  do i=1, nzin
+    if (a%val(i) /= czero) then
+      j = j + 1
+      a%val(j) = a%val(i)
+      a%ia(j)  = a%ia(i)
+      a%ja(j)  = a%ja(i)
+    end if
+  end do
+  call a%set_nzeros(j) 
+  call a%trim()
+end subroutine psb_c_coo_clean_zeros
+
+
 
 subroutine  psb_c_coo_allocate_mnnz(m,n,a,nz) 
   use psb_c_base_mat_mod, psb_protect_name => psb_c_coo_allocate_mnnz

base/serial/impl/psb_d_base_mat_impl.F90

@@ -318,6 +318,22 @@ subroutine psb_d_base_mv_from_fmt(a,b,info)
 
 end subroutine psb_d_base_mv_from_fmt
 
+subroutine  psb_d_base_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_d_base_mat_mod, psb_protect_name => psb_d_base_clean_zeros
+  implicit none 
+  class(psb_d_base_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_), intent(out)              :: info
+  !
+  type(psb_d_coo_sparse_mat) :: tmpcoo
+
+  call a%mv_to_coo(tmpcoo,info)
+  if (info == 0) call tmpcoo%clean_zeros(info)  
+  if (info == 0) call a%mv_from_coo(tmpcoo,info)
+  
+end subroutine psb_d_base_clean_zeros
+
+
 subroutine psb_d_base_csput_a(nz,ia,ja,val,a,imin,imax,jmin,jmax,info,gtl) 
   use psb_error_mod
   use psb_d_base_mat_mod, psb_protect_name => psb_d_base_csput_a

base/serial/impl/psb_d_coo_impl.f90

@@ -329,6 +329,31 @@ subroutine  psb_d_coo_trim(a)
 
 end subroutine psb_d_coo_trim
 
+subroutine  psb_d_coo_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_d_base_mat_mod, psb_protect_name => psb_d_coo_clean_zeros
+  implicit none 
+  class(psb_d_coo_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_) :: info
+  !
+  integer(psb_ipk_) :: i,j,k, nzin
+
+  info = 0 
+  nzin = a%get_nzeros()
+  j = 0
+  do i=1, nzin
+    if (a%val(i) /= dzero) then
+      j = j + 1
+      a%val(j) = a%val(i)
+      a%ia(j)  = a%ia(i)
+      a%ja(j)  = a%ja(i)
+    end if
+  end do
+  call a%set_nzeros(j) 
+  call a%trim()
+end subroutine psb_d_coo_clean_zeros
+
+
 
 subroutine  psb_d_coo_allocate_mnnz(m,n,a,nz) 
   use psb_d_base_mat_mod, psb_protect_name => psb_d_coo_allocate_mnnz

base/serial/impl/psb_s_base_mat_impl.F90

@@ -318,6 +318,22 @@ subroutine psb_s_base_mv_from_fmt(a,b,info)
 
 end subroutine psb_s_base_mv_from_fmt
 
+subroutine  psb_s_base_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_s_base_mat_mod, psb_protect_name => psb_s_base_clean_zeros
+  implicit none 
+  class(psb_s_base_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_), intent(out)              :: info
+  !
+  type(psb_s_coo_sparse_mat) :: tmpcoo
+
+  call a%mv_to_coo(tmpcoo,info)
+  if (info == 0) call tmpcoo%clean_zeros(info)  
+  if (info == 0) call a%mv_from_coo(tmpcoo,info)
+  
+end subroutine psb_s_base_clean_zeros
+
+
 subroutine psb_s_base_csput_a(nz,ia,ja,val,a,imin,imax,jmin,jmax,info,gtl) 
   use psb_error_mod
   use psb_s_base_mat_mod, psb_protect_name => psb_s_base_csput_a

base/serial/impl/psb_s_coo_impl.f90

@@ -329,6 +329,31 @@ subroutine  psb_s_coo_trim(a)
 
 end subroutine psb_s_coo_trim
 
+subroutine  psb_s_coo_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_s_base_mat_mod, psb_protect_name => psb_s_coo_clean_zeros
+  implicit none 
+  class(psb_s_coo_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_) :: info
+  !
+  integer(psb_ipk_) :: i,j,k, nzin
+
+  info = 0 
+  nzin = a%get_nzeros()
+  j = 0
+  do i=1, nzin
+    if (a%val(i) /= szero) then
+      j = j + 1
+      a%val(j) = a%val(i)
+      a%ia(j)  = a%ia(i)
+      a%ja(j)  = a%ja(i)
+    end if
+  end do
+  call a%set_nzeros(j) 
+  call a%trim()
+end subroutine psb_s_coo_clean_zeros
+
+
 
 subroutine  psb_s_coo_allocate_mnnz(m,n,a,nz) 
   use psb_s_base_mat_mod, psb_protect_name => psb_s_coo_allocate_mnnz

base/serial/impl/psb_z_base_mat_impl.F90

@@ -318,6 +318,22 @@ subroutine psb_z_base_mv_from_fmt(a,b,info)
 
 end subroutine psb_z_base_mv_from_fmt
 
+subroutine  psb_z_base_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_z_base_mat_mod, psb_protect_name => psb_z_base_clean_zeros
+  implicit none 
+  class(psb_z_base_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_), intent(out)              :: info
+  !
+  type(psb_z_coo_sparse_mat) :: tmpcoo
+
+  call a%mv_to_coo(tmpcoo,info)
+  if (info == 0) call tmpcoo%clean_zeros(info)  
+  if (info == 0) call a%mv_from_coo(tmpcoo,info)
+  
+end subroutine psb_z_base_clean_zeros
+
+
 subroutine psb_z_base_csput_a(nz,ia,ja,val,a,imin,imax,jmin,jmax,info,gtl) 
   use psb_error_mod
   use psb_z_base_mat_mod, psb_protect_name => psb_z_base_csput_a

base/serial/impl/psb_z_coo_impl.f90

@@ -329,6 +329,31 @@ subroutine  psb_z_coo_trim(a)
 
 end subroutine psb_z_coo_trim
 
+subroutine  psb_z_coo_clean_zeros(a, info)
+  use psb_error_mod
+  use psb_z_base_mat_mod, psb_protect_name => psb_z_coo_clean_zeros
+  implicit none 
+  class(psb_z_coo_sparse_mat), intent(inout) :: a
+  integer(psb_ipk_) :: info
+  !
+  integer(psb_ipk_) :: i,j,k, nzin
+
+  info = 0 
+  nzin = a%get_nzeros()
+  j = 0
+  do i=1, nzin
+    if (a%val(i) /= zzero) then
+      j = j + 1
+      a%val(j) = a%val(i)
+      a%ia(j)  = a%ia(i)
+      a%ja(j)  = a%ja(i)
+    end if
+  end do
+  call a%set_nzeros(j) 
+  call a%trim()
+end subroutine psb_z_coo_clean_zeros
+
+
 
 subroutine  psb_z_coo_allocate_mnnz(m,n,a,nz) 
   use psb_z_base_mat_mod, psb_protect_name => psb_z_coo_allocate_mnnz