Introduction

Sometimes our work goes deep into our brain. A bit like Don Quixote and the windmills, a sick statistical mind looks at Sagrada Familia, Barcelona's iconic church (figure 1), and sees its resemblance to spline basis functions. Then one wonders…would it work? Maybe Gaudí's masterpiece still has some hidden secrets we have yet to unveil. In this paper, basis functions approximating the shape of Sagrada Familia were used to smooth the daily mortality counts in Barcelona during the year 2009, as a fun way to give a flavour on how parametric spline methods work. All this was done with a wisp of hope for serendipitously discovering a revolutionary new statistical tool.