text: a program to calculate this:pn(x)=y0l0(x)+y1l1(x)+...+ynln(x)which:li(x)= n∏(x-xj)/(xi-xj)j=0&j≠i in c? this guestion is about numeric calculation about lagranzh methode li(x)=  n         ∏(x-xj)/(xi-xj)         j=0&j≠i for numerics of this type you might want to check out netlib: http://www.netlib.org use the  "search" button and search on lagrange.  you'll get c and fortran programs.