Re: slot
- To: mathgroup at smc.vnet.net
- Subject: [mg28050] Re: slot
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Thu, 29 Mar 2001 03:24:15 -0500 (EST)
- References: <99s682$pbr@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Bob, One reason is convenience: in the middle of some progam we can use Times[#1,#2,#3]& (or Times[##]& or Function[{x,y,z}, x y z]) without needing to make a definition like those you give for g2 and g3. There is also some speed advantage in avoiding having to look up a definition. g2[x_,y_,z_]:=Times[x,y,z] g3:=Times[#1,#2,#3]& Do[g2[2,3,4],{10000}]//Timing {0.88 Second,Null} Do[g3[2,3,4],{10000}]//Timing {0.66 Second,Null} Do[Function[{x,y,z},x *y *z][2,3,4],{10000}]//Timing {0.77 Second,Null} Do[Times[#1,#2,#3]&[2,3,4],{10000}]//Timing {0.44 Second,Null} Do[Times[##]&[2,3,4],{10000}]//Timing {0.55 Second,Null} -- Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565 "Robert-Lewis HYDE" <bobhyde at wanadoo.fr> wrote in message news:99s682$pbr at smc.vnet.net... > hello, > For those who never dared ask. > > g2[x_,y_,z_]:=Times[x,y,z] > > g3:=Times[#1,#2,#3]& > > g2[1,2,3]===g3[1,2,3] > > True > > Why or when should we go in for the g3 format ? > > It confuses us ordinary folks (me) who just want to go forth and multiply. > > Bob > >