2.87 How to divide each element by its position in a list?
Given \(A=[2, 3, 5, 7, 11, 13, 17, 19, 23, 29]\) change it to
\[ [2,{\frac {3}{2}},{\frac {5}{3}},{\frac {7}{4}},{\frac {11}{5}},{\frac {13} {6}},{\frac {17}{7}},{\frac {19}{8}},{\frac {23}{9}},{\frac {29}{10}}] \]
2.87.1 Mathematica
A = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29};
MapIndexed[(#1/First[#2]) &, A]
\[ \left \{2,\frac {3}{2},\frac {5}{3},\frac {7}{4},\frac {11}{5},\frac {13}{6},\frac {17}{7},\frac {19}{8},\frac {23}{9},\frac {29}{10}\right \} \]
2.87.2 Maple
A:= [2, 3, 5, 7, 11, 13, 17, 19, 23, 29];
((x,y)->x/y)~(A,[seq(i,i=1..numelems(A))])
#or simpler might be to map the divsion operator directly
`/` ~ (A,[seq(i,i=1..numelems(A))])
\[ [2,{\frac {3}{2}},{\frac {5}{3}},{\frac {7}{4}},{\frac {11}{5}},{\frac {13} {6}},{\frac {17}{7}},{\frac {19}{8}},{\frac {23}{9}},{\frac {29}{10}}] \]
2.87.3 Matlab
A=[2, 3, 5, 7, 11, 13, 17, 19, 23, 29];
A./(1:length(A))
2.0000 1.5000 1.6667 1.7500 2.2000 2.1667 2.4286 2.3750 2.5556 2.9000