Re: Questions on Apply function
- To: mathgroup at smc.vnet.net
- Subject: [mg62920] Re: Questions on Apply function
- From: Peter Pein <petsie at dordos.net>
- Date: Thu, 8 Dec 2005 00:06:31 -0500 (EST)
- References: <dn5ogd$nks$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
PengYu.UT at gmail.com schrieb:
> Please look at the following code. I'm wondering the output 1 doesn't
> give me the right answer. 6435-4545 should be 1890. Is there anything
> wrong with input 1? It seems that it is correct, because input 3 works
> well.
>
> Thanks,
> Peng
>
> In[1]:=
> Apply[(#+{-6750,6435})&,{{6945,-4545},{6945, -4545}},{1}]
>
> Out[1]=
> {{195,13380},{195, 13380}}
>
> In[2]:=
> {-6750,6435}+{6945,-4545}
>
> Out[2]=
> {195,1890}
>
> In[3]:=
> Apply[(#+{a,b})&,{{a1,b1},{a2,b2},{a3,b3}},{1}]
>
> Out[3]=
> {{a+a1,a1+b},{a+a2,a2+b},{a+a3,a3+b}}
>
Hi Peng,
if input 3 works well, then input one works too (have a closer look at
the _out_put ;-) )
You try to use a function with one parameter as if it had two arguments.
Try
Map[# + {-6750, 6435}&, {{6945, -4545}, {6945, -4545}}, {1}]
--> {{195, 1890}, {195, 1890}} (* replaces "#" by "{6945, -4545}" *)
or
Apply[{##} + {-6750, 6435}&, {{6945, -4545}, {6945, -4545}}, {1}]
--> same output
which replaces "##" by the _sequence_ "945, -4545".
Peter