6.2.1  Array of values of a sequence

The tablefunc command fills two columns of a spreadsheet with a table of values of a function. The spreadsheet can be opened with Alt+T (see Section 2.10).

• tablefunc takes four arguments:
  • f(x), a formula for a function.
  • x, the variable.
  • x₀, the beginning value of x.
  • inc, an increment for x.
• tablefunc(f(x),x,x₀,inc) fills two columns of the spreadsheet, the current column and the following column, starting with the chosen cell. The current column starts with the variable x, followed by the initial value x₀, then x₀+inc, x₀+2inc, …. The following column starts with the formula f(x), followed by f(x) evaluated at the values in the first column. (If the current cell is column C, row n, it will contain x, the cell below it will contain inc, and the cell below it in row k will contain =C(k−1)+C$(n+1), and the corresponding cells in the next column will contain =evalf(subst(D$n,C$n,Ck)).)

Example

To display the values of the sequence u_n=sin(n), select a cell of a spreadsheet (for example C0) and input tablefunc(sin(n),n,0,1) in the spreadsheet commandline. You get:

The graphic representation may be plotted with the plotfunc command (see 19.2.1).