surface uniformity returns vector instead of scalar.

cross-ref EP1047

@Stefan @Prashant

Looks much better.

before

# Time          weightedUniformity(p)   weightedUniformity(rho) weightedUniformity(U)   weightedUniformity(rhoU)
1               9.447770e-01    9.447770e-01    (9.040119e-01 0.000000e+00 0.000000e+00)        (9.040119e-01 0.000000e+00 0.000000e+00)
2               9.398396e-01    9.432529e-01    (9.023962e-01 0.000000e+00 0.000000e+00)        (9.023249e-01 0.000000e+00 0.000000e+00)
3               9.186323e-01    9.164396e-01    (8.764084e-01 0.000000e+00 0.000000e+00)        (8.662521e-01 0.000000e+00 0.000000e+00)
4               9.080936e-01    9.021887e-01    (8.546137e-01 0.000000e+00 0.000000e+00)        (8.438405e-01 0.000000e+00 0.000000e+00)
5               9.058176e-01    8.983377e-01    (8.381904e-01 0.000000e+00 0.000000e+00)        (8.310451e-01 0.000000e+00 0.000000e+00)

after

# Time          weightedUniformity(p)   weightedUniformity(rho) weightedUniformity(U)   weightedUniformity(rhoU)
1               9.447770e-01    9.447770e-01    9.040119e-01    9.040119e-01
2               9.398396e-01    9.432529e-01    9.023962e-01    9.023249e-01
3               9.186323e-01    9.164396e-01    8.764084e-01    8.662521e-01
4               9.080936e-01    9.021887e-01    8.546137e-01    8.438405e-01

mentioned in commit a98527c3874e3f0510062576fdce81965345278d

closed