[en] The possible values of the pion charge radius rsub(π) are correlated with those of the pionic contribution asub(μ)(π⁺π^-) to the muon magnetic moment in terms of the normalization of the pion form factor, its modulus on part of the unitarity cut, and the quality of the chisup(2)-fit to values measured for it in a number of spacelike points. The correlation is expressed as a 3-dimensional set (D) of values (h'(0),||h||sup(2),chi) allowed for the functions h(z) analytic in the unit disk and belonging to a set Ω in the Hilbert space Hsup(2). The set D, which depends through Ω and chi on the information used, has simple convexity properties. Its computation is reduced to a problem of finite-dimensional convex optimization. (author)