Functions
	disp (' ***check solution restricted to mat(1:n-10, 1:n-10)')
if(norm(mat(1:n-10, 1:n-10) *id.SOL(1:n-10) - ones(n-10, 1), 'inf') > sqrt(eps)) disp('WARNING else	disp ('SCHUR SOLUTION CHECK1 OK')
end	norm (mat(1:n-10, 1:n-10) id.SOL(1:n-10) - ones(n-10, 1), 'inf') % we want to use Schur complement to solve % A sol
id	RHS (1:n-10)
	disp (' ***check complete solution')
if(norm(r, 'inf') > sqrt(eps)) disp('WARNING else	disp ('SCHUR SOLUTION CHECK2 OK')
end	norm (r, 'inf') %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % NOW TRY REDUCED RHS FUNCTIONALITY %(easier to use than previous % computations) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% id.JOB
Do forward solution step to obtain a reduced RHS id	ICNTL (26)
	disp (' ***check solution when REDRHS is used')
if(norm(r, 'inf') > sqrt(eps)) disp('WARNING else	disp ('SCHUR SOLUTION CHECK3 OK')

Variables
	id = dmumps(id)
load	lhr01
	mat = Problem.A
	themax = max(max(abs(mat)))
	n = size(mat,1)
initialization of Schur option id	VAR_SCHUR = [n-9:n]
	JOB
id	RHS = ones(size(mat,1),1)
	rhsy = ones(10,1)-mat(n-9:n,1:n-10)*sol1
TO	CHANGE
	rhsx = mat(1:n-10,n-9:n)*y
	x = sol1-rhsx
	sol = [x
	y
	r = mat*sol - ones(n,1)
Solve the problem on the interface id	REDRHS = id.SCHUR \ id.REDRHS

Function Documentation

◆ disp() [1/6]

disp ( ' ***check complete solution' )

◆ disp() [2/6]

disp ( ' ***check solution restricted to mat(1:n-10, 1:n-10)' )

◆ disp() [3/6]

disp ( ' ***check solution when REDRHS is used' )

◆ disp() [4/6]

if(norm(mat(1:n-10, 1:n-10) *id.SOL(1:n-10) - ones(n-10, 1), 'inf') > sqrt(eps)) disp( 'WARNING else disp ( 'SCHUR SOLUTION CHECK1 OK' )

◆ disp() [5/6]

if(norm(r, 'inf') > sqrt(eps)) disp( 'WARNING else disp ( 'SCHUR SOLUTION CHECK2 OK' )

◆ disp() [6/6]

if(norm(r, 'inf') > sqrt(eps)) disp( 'WARNING else disp ( 'SCHUR SOLUTION CHECK3 OK' )

◆ ICNTL()

Do forward solution step to obtain a reduced RHS id ICNTL ( 26 )

◆ norm() [1/2]

end norm	(	mat(1:n-10, 1:n-10) *id.SOL(1:n-10) - ones(n-10, 1)	,
		'inf'	)

◆ norm() [2/2]

end norm	(	r	,
		'inf'	)

◆ RHS()

id RHS ( 1:n- 10 )

Variable Documentation

◆ CHANGE

TO CHANGE

Definition at line 43 of file schur_example.m.

◆ id

id = dmumps(id)

Definition at line 5 of file schur_example.m.

◆ JOB

id JOB

Initial value:

= 6 means analysis+facto+solve

id.JOB = 6

id

initmumps id

Definition multiplerhs_example.m:4

JOB

#define JOB

Definition mumpsmex.c:33

Definition at line 15 of file schur_example.m.

◆ lhr01

load lhr01

Definition at line 6 of file schur_example.m.

◆ mat

mat = Problem.A

Definition at line 7 of file schur_example.m.

◆ n

n = size(mat,1)

Definition at line 9 of file schur_example.m.

◆ r

r = mat*sol - ones(n,1)

Definition at line 55 of file schur_example.m.

◆ REDRHS

Solve the problem on the interface id REDRHS = id.SCHUR \ id.REDRHS

Definition at line 79 of file schur_example.m.

◆ RHS

id RHS = ones(size(mat,1),1)

Definition at line 17 of file schur_example.m.

◆ rhsx

rhsx = mat(1:n-10,n-9:n)*y

Definition at line 48 of file schur_example.m.

◆ rhsy

rhsy = ones(10,1)-mat(n-9:n,1:n-10)*sol1

Definition at line 40 of file schur_example.m.

◆ sol

sol = [x

Definition at line 54 of file schur_example.m.

◆ themax

themax = max(max(abs(mat)))

Definition at line 8 of file schur_example.m.

◆ VAR_SCHUR

initialization of Schur option id VAR_SCHUR = [n-9:n]

Definition at line 13 of file schur_example.m.

◆ x

x = sol1-rhsx

Definition at line 53 of file schur_example.m.

◆ y

y