RE: thanks for the help with list - extended syntax question
- To: mathgroup at smc.vnet.net
- Subject: [mg40642] RE: [mg40617] thanks for the help with list - extended syntax question
- From: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>
- Date: Sat, 12 Apr 2003 03:08:05 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
>-----Original Message----- >From: Nathan Moore [mailto:nmoore at physics.umn.edu] To: mathgroup at smc.vnet.net >Sent: Friday, April 11, 2003 8:03 AM >To: mathgroup at smc.vnet.net >Subject: [mg40642] [mg40617] thanks for the help with list - extended syntax >question > > >Why is it in Mathematica that I can't operate on lists as if >they are long >arrays(in the style of c) It would be orders of magnitude >easier or me to >just type, > data = {{x1,y1},{x2,y2}...{xn,yn}} >and then find the desired sum like, > for(i=0,sum=0;i<;i++) { sum += data[[i,1]]*data[[i,2]]; } > >It seems idiotic that syntax like this (which most of the >scientific world >would understand) is not allowed! I hate learning new >(redundant) computer >languages!!! > >Nathan > > Nathan In[4]:= For[i = 1; sum = 0, i <= Floor[Length[d]/2], i++, sum += d[[i, 1]]*d[[i, 3]]]; sum Out[5]= a1 c1 + a2 c2 + a3 c3 + a4 c4 Conceptionally this is 100% percent what you wanted. That (strange) syntax you applied, is pure C, a low level implementation language from the ending 60's, only mastered by a minority of programmers, unknown to the scientific world in near future. Not so Mathematica! Tempora mutantur et nos mutamur in eos. -- Hartmut Wolf