  We compute the Tan's contact of a weakly interacting Bose gas at zero
temperature in a cigar-shaped configuration. Using an effective one-dimensional
Gross-Pitaeskii equation and Bogoliubov theory, we derive an analytical formula
that interpolates between the three-dimensional and the one-dimensional
mean-field regimes. In the strictly one-dimensional limit, we compare our
results with Lieb-Liniger theory. Our study can be a guide for actual
experiments interested in the study of Tan's contact in the dimensional
crossover.
