pde12_eq.c running
differential equation to solve
d^2u/dx^2 + 3 du/dx + 2 u(x) = c(x,y) = -sin(x)/2 + cos(x)
uniform grid on  0 to 9/2 Pi
known Solution, for testing method
u(x) = sin(x)/4 + cos(x)/4 

xg( 0)=0.000000
xg( 1)=0.543737
xg( 2)=1.087474
xg( 3)=1.631212
xg( 4)=2.174949
xg( 5)=2.718686
xg( 6)=3.262423
xg( 7)=3.806160
xg( 8)=4.349898
xg( 9)=4.893635
xg(10)=5.437372
xg(11)=5.981109
xg(12)=6.524846
xg(13)=7.068583
xg(14)=7.612321
xg(15)=8.156058
xg(16)=8.699795
xg(17)=9.243532
xg(18)=9.787269
xg(19)=10.331007
xg(20)=10.874744
xg(21)=11.418481
xg(22)=11.962218
xg(23)=12.505955
xg(24)=13.049693
xg(25)=13.593430
xg(26)=14.137167
xmin=0.000000, xmax=14.137167, hx=0.543737, nx=27
u(0.5)=0.339252
c(0.5)=0.637870

internal cells zeroed 
matrix initialized
check_soln against PDE
check soln against PDE max error=1.05873


exact solution u, computed us, error
xg[ 0]=0.00000, u=   2.500000e-01, us=   2.500000e-01, err=   0.000000e+00
xg[ 1]=0.54374, u=   3.432798e-01, us=   3.432894e-01, err=   9.627446e-06
xg[ 2]=1.08747, u=   3.375448e-01, us=   3.375536e-01, err=   8.834517e-06
xg[ 3]=1.63121, u=   2.344493e-01, us=   2.344555e-01, err=   6.222902e-06
xg[ 4]=2.17495, u=   6.372978e-02, us=   6.373376e-02, err=   3.981545e-06
xg[ 5]=2.71869, u=  -1.253718e-01, us=  -1.253693e-01, err=   2.435852e-06
xg[ 6]=3.26242, u=  -2.783114e-01, us=  -2.783099e-01, err=   1.456082e-06
xg[ 7]=3.80616, u=  -3.509756e-01, us=  -3.509747e-01, err=   8.594842e-07
xg[ 8]=4.34990, u=  -3.224053e-01, us=  -3.224048e-01, err=   5.037533e-07
xg[ 9]=4.89363, u=  -2.008412e-01, us=  -2.008409e-01, err=   2.940704e-07
xg[10]=5.43737, u=  -2.134702e-02, us=  -2.134685e-02, err=   1.712704e-07
xg[11]=5.98111, u=   1.643045e-01, us=   1.643046e-01, err=   9.961753e-08
xg[12]=6.52485, u=   3.025644e-01, us=   3.025644e-01, err=   5.789677e-08
xg[13]=7.06858, u=   3.535534e-01, us=   3.535534e-01, err=   3.363408e-08
xg[14]=7.61232, u=   3.025644e-01, us=   3.025644e-01, err=   1.953411e-08
xg[15]=8.15606, u=   1.643045e-01, us=   1.643045e-01, err=   1.134334e-08
xg[16]=8.69980, u=  -2.134702e-02, us=  -2.134702e-02, err=   6.586447e-09
xg[17]=9.24353, u=  -2.008412e-01, us=  -2.008412e-01, err=   3.824192e-09
xg[18]=9.78727, u=  -3.224053e-01, us=  -3.224053e-01, err=   2.220318e-09
xg[19]=10.33101, u=  -3.509756e-01, us=  -3.509756e-01, err=   1.289090e-09
xg[20]=10.87474, u=  -2.783114e-01, us=  -2.783114e-01, err=   7.484236e-10
xg[21]=11.41848, u=  -1.253718e-01, us=  -1.253718e-01, err=   4.345193e-10
xg[22]=11.96222, u=   6.372978e-02, us=   6.372978e-02, err=   2.522752e-10
xg[23]=12.50596, u=   2.344493e-01, us=   2.344493e-01, err=   1.464503e-10
xg[24]=13.04969, u=   3.375448e-01, us=   3.375448e-01, err=   8.504855e-11
xg[25]=13.59343, u=   3.432798e-01, us=   3.432798e-01, err=   4.937793e-11
xg[26]=14.13717, u=   2.500000e-01, us=   2.500000e-01, err=   0.000000e+00
avg_error=1.38498e-06, max_error=9.62745e-06
writing pde12_eq_c.dat
finished writing pde12_eq_c.dat
finished pde12_eq.c