jats:titleAjats:scbstract</jats:sc> </jats:title>jats:pThe polarimeter vector field for multibody decays of a spin-half baryon is introduced as a generalisation of the baryon asymmetry parameters. Using a recent amplitude analysis of the jats:inline-formulajats:alternativesjats:tex-math$$ {\Lambda}_c^{+} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> mml:msubsup mml:miΛ</mml:mi> mml:mic</mml:mi> mml:mo+</mml:mo> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> → jats:italicpK</jats:italic>jats:supjats:italic−</jats:italic></jats:sup>jats:italicπ</jats:italic>jats:sup+</jats:sup> decay performed at the LHCb experiment, we compute the distribution of the kinematic-dependent polarimeter vector for this process in the space of Mandelstam variables to express the polarised decay rate in a model-agnostic form. The obtained representation can facilitate polarisation measurements of the jats:inline-formulajats:alternativesjats:tex-math$$ {\Lambda}_c^{+} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> mml:msubsup mml:miΛ</mml:mi> mml:mic</mml:mi> mml:mo+</mml:mo> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> baryon and eases inclusion of the jats:inline-formulajats:alternativesjats:tex-math$$ {\Lambda}_c^{+} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> mml:msubsup mml:miΛ</mml:mi> mml:mic</mml:mi> mml:mo+</mml:mo> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula>jats:italic→ pK</jats:italic>jats:supjats:italic−</jats:italic></jats:sup>jats:italicπ</jats:italic>jats:sup+</jats:sup> decay mode in hadronic amplitude analyses.</jats:p>