S = vec2scal(V) returns scalar field(s) S given by the norm of the
vector field(s) V. The vector field(s) V can be obtained from loadvec
or loadset and the scalar field(s) S can be displayed by showscal.
S = vec2scal(V,MODE) specifies the conversion MODE:
norm norm (ux^2 + uy^2)^(1/2); by default.
ux, uy x or y component of the vector field
ken kinetic energy, norm^2 / 2
curl (or rot) curl
absrot absolute value of the rotational
div 2D divergence (dux/dx + duy/dy)
ens enstrophy (=square of vorticity)
strain norm of the strain rate, sqrt(s1^2 + s2^2),
where s1 and s2 are the 2D strain eigenvalues.
eps squared strain rate, s1^2 + s2^2
duxdx, duxdy, duydx, duydy spatial derivatives (du_i / dx_j)
angle velocity angle (tan(angle)=vy/vx)
Adding '-' (minus sign) before MODE (eg, '-rot') inverts the result.
The resulting scalar field S contains the following fields:
x,y: vectors containing the X and Y coordinates
w: matrix of scalar elements
namex, unitx, namey, unity: strings for the name and unit of coord
namew, unitw: strings for the name and unit of the matrix w
name: name of the VEC file from which originates V
setname: name of the current directory
history: Remind from which command S has been obtained
Note: for the derivative operators (rot, div etc.), the size of the
field is decreased by 1 unit. The x and y coordinates are interpolated.
S = vec2scal(FILE) is a shortcut for S = vec2scal(loadvec(FILE)).
vec2scal(...), without output argument, shows the result with showscal.
Examples:
showscal(vec2scal(v,'div'));
showscal(vec2scal(filterf(loadset,2),'rot'));
stat_rot = statf(vec2scal(v,'rot'));
vec2scal *.vec
F. Moisy
Revision: 1.42, Date: 2005/11/18.
See Also
showvec, showscal, operf.