Calculate the Q_NX score (Chen & Buja 2006, the notation in the publication is M_k). Which is the fraction of points that remain inside the same K-ary neighborhood in high and low dimensional space.
See also
Other Quality scores for dimensionality reduction:
AUC_lnK_R_NX,dimRedResult-method,
LCMC,dimRedResult-method,
Q_global,dimRedResult-method,
Q_local,dimRedResult-method,
R_NX,dimRedResult-method,
cophenetic_correlation,dimRedResult-method,
distance_correlation,dimRedResult-method,
mean_R_NX,dimRedResult-method,
plot_R_NX(),
quality,dimRedResult-method,
reconstruction_error,dimRedResult-method,
reconstruction_rmse,dimRedResult-method,
total_correlation,dimRedResult-method