Re: elementwise vector scalar subtraction

*To*: mathgroup at smc.vnet.net*Subject*: [mg35651] Re: [mg35625] elementwise vector scalar subtraction*From*: Sseziwa Mukasa <mukasa at jeol.com>*Date*: Wed, 24 Jul 2002 02:06:24 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

On Tuesday, July 23, 2002, at 01:51 AM, O.A. Linares, M.D., Ph.D. wrote: > Dear Colleagues, > > I have a t-vector > > t = {0, 1, 1.5, 2, 2.5, 4, 6, 8, 10, 15, 20, 30}; > > I want to subtract 0.15 from each element except the first to get > > tc15 = {0, 1 - 0.15, 1.50 - 0.15, 2 - 0.15, 2.5 - 0.15, 4 - 0.15, 6 - > 0.15, 8 - 0.15, 10 - 0.15, 15 - 0.15, 20 - 0.15, 30 - 0.15}; > > I then want to subtract 0.20 to get > > tc20 = {0, 1 - 0.20, 1.50 - 0.20, 2 - 0.20, 2.5 - 0.20, 4 - 0.20, 6 - > 0.20, 8 - 0.20, 10 - 0.20, 15 - 0.20, 20 - 0.20, 30 - 0.20}; > > Is there a way to automate this process for n subtractions from 0.15 > to 0.30 to yield individual t-vectors for tc15 through tc30 ? > > The only difficulty seems to be retaining the zero at the beginning of the list, so we could just define a pure function to stick it on. The rest can be handled with a simple table so the expression: Block[{temp=Rest[t]},{0,##}&@@@Table[temp-(0.15-i 0.5),{i,0,3}]] should do the trick. Regards, Ssezi