How to get monomials multiplied by each other?

Question

Suppose Subscript[x, #] & /@ {1, 3, 7} that returns {x_1,x_3,x_7}. Now how can I get x_1x_3x_7?

Tried it already...

P.s. I am trying to understand this thread deeper about converting binary mlfs to mlfs.

score 5 · Accepted Answer · edited Apr 13 '17 at 12:55

5

It is due to precedence. Need to use () in this case.

Times @@ (Subscript[x, #] & /@ {1, 3, 7})

Mathematica graphics

See this when-is-fg-not-the-same-as-fg topic for table of precedence in Mathematica.

edited Apr 13 '17 at 12:55

Community

answered Nov 10 '13 at 19:24

Nasser

Yes but my Mathematica is returning {x,3x,7x} -- oouch brackets missing?! So my version operated on the Subscript thing, not the whole thing. Thank you! +1 – hhh Nov 10 '13 at 19:27

score 3 · Answer 2 · answered Nov 10 '13 at 19:44

3

Two more solutions:

Times @@ Thread@Subscript[x, {1, 3, 7}]

In the notebook it can be written more compactly

enter image description here

The second one shows the behavior of /@

Subscript[x, #] & /@ Unevaluated@Times[1, 3, 7]

enter image description here

answered Nov 10 '13 at 19:44

ybeltukov

2 Answers2