GfsOutputLocation

From Gerris

GfsOutputLocation writes the values of all permanent variables at a set of given locations. The first time GfsOutputLocation is called it writes a comment describing the fields being written.

The values are linearly interpolated to the given location using gfs_interpolate().

The syntax in parameter files is as follows:

[ GfsOutput ] X Y Z

where X, Y and Z are the coordinates of the location.

or:

[ GfsOutput ] FILE

where FILE is the name of a text file containing the space-separated X, Y and Z coordinates of a set of locations.

or:

[ GfsOutput ] { X1 Y1 Z1 ... XN YN ZN }

where the Xi, Yi and Zi are the coordinates of the set of locations.

An optional parameter block can also be appended to the syntax above, for example:

[ GfsOutput ] X Y Z {
  label = "Location 1"
  precision = %g
  interpolate = 1
}

with

label

a label to be displayed by GfsView when using the "Location" object,

precision

the C-format used to output the text-formatted values of variables (default is %g),

interpolate

whether to interpolate (bilinearly) at the given location or just return the value of the variable for the cell which contains this particular location (default is 1).

Note

There is no constraint on the coordinates of the input locations but only locations which are within the simulation domain will be written in the output file.

Examples

• Tsunami runup onto a complex three-dimensional beach

    OutputLocation { istep = 1 } input 1e-3 1.7 0

    OutputLocation { istep = 1 } p5 4.521 1.196 0

    OutputLocation { istep = 1 } p7 4.521 1.696 0

    OutputLocation { istep = 1 } p9 4.521 2.196 0

• The 2004 Indian Ocean tsunami

    OutputLocation { start = 6900 } jason.txt jason.xy

• Viscous flow past a sphere

    OutputLocation { step = 0.1 } {
	awk 'BEGIN { t = 2.; oldl = -1.; oldt = 0.; } {
          if ($1 != t) { t = $1; x1 = $2; u1 = $7; }
          else {
            x2 = $2; u2 = $7;
            if (u1 <= 0. && u2 > 0.) {
              l = (u1*x2 - u2*x1)/(u1 - u2) - A0;
              dl = (l - oldl)/(t - oldt);
              print t, l, dl;
              fflush (stdout);
              oldl = l;
              oldt = t;
            }
            x1 = x2; u1 = u2;
          }
        }' > l-LEVEL-RE
    } axis

• Lid-driven cavity at Re=1000

  OutputLocation { start = end } xprof xprofile

  OutputLocation { start = end } yprof yprofile

• Lid-driven cavity at Re=1000 (explicit scheme)

  OutputLocation { start = end } xprof ../xprofile

  OutputLocation { start = end } yprof ../yprofile

• Lid-driven cavity with a non-uniform metric

  OutputLocation { start = end } xprof xprofile

  OutputLocation { start = end } yprof yprofile

• Lid-driven cavity on an anisotropic mesh

  OutputLocation { start = end } xprof xprofile

  OutputLocation { start = end } yprof yprofile

• Creeping Couette flow of Generalised Newtonian fluids

  OutputLocation { start = end } { awk '{if ($1 != "#") print $2,$8;}' > prof-MODEL } profile

• Transcritical flow with multiple layers

    OutputLocation { start = end } { awk -v nl=NL -f uprof.awk > uprof-10-LEVEL-NL } 10. 10.49 0

    OutputLocation { start = end } { awk -v nl=NL -f uprof.awk > uprof-15-LEVEL-NL } 15. 10.49 0

    OutputLocation { start = end } { awk -v nl=NL -f uprof.awk > uprof-20-LEVEL-NL } 20. 10.49 0

• Poisson equation on a sphere with Gaussian forcing

  OutputLocation { start = end } prof.dat profile

• Gaussian forcing using longitude-latitude coordinates

  OutputLocation { start = end } prof.dat profile

• Relaxation of a charge bump

    OutputLocation { istep = 10 } { 
        awk '
         BEGIN {
                a = 0.05 
                perm = 2.
                K = 1.
                rhoinic = 1./a/sqrt(2.*3.14159265358979)
         } 
         {
            if ($1 != "#")
                print $1, rhoinic*exp(-$1*K/perm), $12;
         }' > timevol-SCHEME
    } { 0. 0. 0. }

• Equilibrium of a droplet suspended in an electric field

    OutputLocation { start = end } {
	awk '
	BEGIN {
	    R0 = 0.1
	    Ef = 1.34
	    mu = 0.1
	    ep2 = 1.
	    R = 5.1
	    Q = 10.
	    lambda = 1.
	    factor = R0*Ef*Ef*ep2/mu
	    theta = 3.14159265358979/4.
	    A=-9./10.*(R-Q)/(R+2.)**2/(1.+lambda)
	    st = sr = 0.
	    sn = 0.
	    
	}
	function radius(x,y)
	{
	    return sqrt(x*x+y*y)/R0
	}
	function vr(x,y,vx,vy)
	{
	    return (vx*x+vy*y)/(factor*sqrt(x*x+y*y))
	}
	function vt(x,y,vx,vy)
	{
	    return (vx*y-vy*x)/(factor*sqrt(x*x+y*y))
	}
	#  Theoretical velocity profile
	function vtr(x)
	{
	    if (x < 1.)
		return A*x*(1.-x**2)*(3.*sin(theta)**2-1.);
	    else
		return A*x**(-2)*(x**(-2)-1.)*(3.*sin(theta)**2-1.);
	}
	function vtt(x)
	{
	    if (x < 1.)
		return 3.*A/2.*x*(1.-5./3.*x**2)*sin(2.*theta);
	    else
		return -A*x**(-4)*sin(2.*theta);
	}
	{
	    if ($1 != "#") {
		r = radius($2,$3)
		tvr = vtr(r)
		tvt = vtt(r)
		print r,vr($2,$3,$7,$8),vt($2,$3,$7,$8),tvr,tvt
		sr += (vr($2,$3,$7,$8) - tvr)**2
		st += (vt($2,$3,$7,$8) - tvt)**2
		sn += 1.
	    }
        }
	END {
	    print sqrt(sr/sn),sqrt(st/sn) > "/dev/stderr"
	}' > fprof
    } thetapi4

• Gouy-Chapman Debye layer

    OutputLocation { start = end } { 
	awk '{ if ($1 != "#") print $2, $9, $12, $13; }' > profile 
    } points