fem_bihar2ds_la.c running.
solve  uxxxx(x,y) + uyyyy(x,y) = f(x,y)
 
f(x,y) := sin(x) + sin(y)
 
in the rectangle   xmin< x <xmax  and  ymin< y <ymax,
 
   subject to boundary conditions of the first kind, Dirichlet
   ub(x,y) := sin(x) + sin(y) 
xmin=  0.000, xmax=  3.142, ymin=  0.000, ymax=  3.142
nx=9, ny=9
x grid and analytic solution at ymin 
i=0, xg[i]=0.000000, ub(xg[i],ymin)=0.000000
i=1, xg[i]=0.392699, ub(xg[i],ymin)=0.382683
i=2, xg[i]=0.785397, ub(xg[i],ymin)=0.707106
i=3, xg[i]=1.178096, ub(xg[i],ymin)=0.923879
i=4, xg[i]=1.570795, ub(xg[i],ymin)=1.000000
i=5, xg[i]=1.963494, ub(xg[i],ymin)=0.923880
i=6, xg[i]=2.356192, ub(xg[i],ymin)=0.707108
i=7, xg[i]=2.748891, ub(xg[i],ymin)=0.382686
i=8, xg[i]=3.141590, ub(xg[i],ymin)=0.000003
 
y grid and analytic solution at xmin 
ii=0, yg[ii]=0.000000, ub(xmin,yg[ii])=0.000000 
ii=1, yg[ii]=0.392699, ub(xmin,yg[ii])=0.382683 
ii=2, yg[ii]=0.785397, ub(xmin,yg[ii])=0.707106 
ii=3, yg[ii]=1.178096, ub(xmin,yg[ii])=0.923879 
ii=4, yg[ii]=1.570795, ub(xmin,yg[ii])=1.000000 
ii=5, yg[ii]=1.963494, ub(xmin,yg[ii])=0.923880 
ii=6, yg[ii]=2.356192, ub(xmin,yg[ii])=0.707108 
ii=7, yg[ii]=2.748891, ub(xmin,yg[ii])=0.382686 
ii=8, yg[ii]=3.141590, ub(xmin,yg[ii])=0.000003 
 
 
calling gauleg xmin=0.000000, xmax=3.141590, npx=9 
xx[1]=0.050014, xx[2]=0.257562, wx[1]=0.127665, wx[2]=0.283761 
calling gauleg ymin=0.000000, ymax=3.141590, npy=9 
yy[1]=0.050014, yy[2]=0.257562, wy[1]=0.127665, wy[2]=0.283761 
galk(xx[2],yy[2])=-10699.4
galf(xx[2],yy[2])=1.12064
time to initialize = 0.000000 seconds 
compute stiffness matrix 
k computed stiffness matrix, see above 
 f computed forcing function, see above 
 time for stiffness and forcing = 150.000000 seconds 
solve time = 150.000000 seconds 
writing fem_bihar2ds_la_c.dat 
finished writing fem_bihar2ds_la_c.dat 
check_soln values 
maxerr=2.56968, rmserr=0.920623, avgerr=0.699091 
ug computed Galerkin, Ua analytic, error 
xmax=3.141590, ymax=3.141590, nx=9, ny=9, npx=9, npy=9 
                  maxerr=2.12475, avgerr=0.730636 

total CPU time = 150.000000 seconds 
calling gnuplot