Re: Complicated Rotation

*To*: mathgroup at smc.vnet.net*Subject*: [mg27262] Re: Complicated Rotation*From*: Tom Burton <tburton at cts.com>*Date*: Wed, 14 Feb 2001 03:41:29 -0500 (EST)*Organization*: Brahea Consulting*References*: <96as1b$6ep@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hello Yas, What seems to be required to is successively premultiply r[t] for t=t1,t2,t3,... to s0. I like to this kind of thing as follows. I'll assume that the increment in t takes on whole numbers. Define the matrix r[t] along the lines of your memo. Then In[50]:= FoldList[r[#2] . #1 & , s0, Range[5]] Out[50]= {s0, r[1] . s0, r[2] . r[1] . s0, r[3] . r[2] . r[1] . s0, r[4] . r[3] . r[2] . r[1] . s0, r[5] . r[4] . r[3] . r[2] . r[1] . s0} This is very simple and easy to read, once you understand FoldList. Tom On 13 Feb 2001 03:42:19 -0500, in comp.soft-sys.math.mathematica you wrote: >Dear mathgroup, >I have a problem that I have been trying to do in mathematica... >And at successive increments of time > >sf[1] = r[1]*s0 >sf[2] = r[2]*sf[1] >sf[3] = r[3]*sf[2] >| >| >sf[n] = r[n]*sf[n-1] Tom