Re: Adding Vectors -- Newbie help please

*To*: mathgroup at smc.vnet.net*Subject*: [mg52059] Re: Adding Vectors -- Newbie help please*From*: "Steve Luttrell" <steve_usenet at _removemefirst_luttrell.org.uk>*Date*: Tue, 9 Nov 2004 01:36:48 -0500 (EST)*References*: <cmfc9b$7k3$1@smc.vnet.net> <cmhut5$ppb$1@smc.vnet.net> <cmklrk$jm3$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Ignore my previous reply to this message. I didn't notice that you were using curvilinear coordinates. Steve Luttrell "motz art" <music at heart.com> wrote in message news:cmklrk$jm3$1 at smc.vnet.net... > Ok; but I was hoping that there is a simpler way than the > following method to add two ac voltage vectors (for example): > > (220V, 225 degrees) > (100V, 16 degrees) > > Clear[r, x, y, Theta, rect, polar] > > rect[r_,Theta_] := { r Cos[Theta Pi/180] , r Sin[Theta Pi/180]} > polar[x_, y_] := {Sqrt[x^2 + y^2], ArcTan[x, y]180/Pi} > > (* Input vectors here *) > v1 := {220, 225}; > v2 := {100, 16}; > > r1:= rect[v1[[1]], v1[[2]] ] // N; > r2:= rect[v2[[1]], v2[[2]] ] // N; > rt := p1 + p2 > > polar[rt[[1]], rt[[2]]] // N > > This just seems so cumbersome, especially when compared to a > scientific calculator. > > > > On Sat, 6 Nov 2004 07:36:05 +0000 (UTC), David Bailey > <dave at Remove_Thisdbailey.co.uk> wrote: > >>motz art wrote: >>> Mathematica v5: How can I input vectors in polar form and >>> rectangular form? >>> >>> Example: >>> >>> a:= (r1, theta1) + (r2, theta2) Polar form. >>> >>> b:= (re1 , j* im1) + (re2, j*im2) Rectangular form >>> >>> I know this should be pretty basic, but I haven't found examples >>> of this kind of input. >>> >>> I would guess it would be something like: >>> >>> Polar[magnitude, phase] >>> Rectangular[Real, Imaginary] >>> >>> but, apparently not. (This is for electronics engineering.) >>> >>> Thanks for any help. >>> >>> >>> >>> >>> >>You can easily write a function to convert from polar to coordinate form: >> >>FromPolar[r_, theta_] := {r Cos[theta], r Sin[theta]} >> >>Note that this assumes your angles are measured in radians. Once all >>your vectors are in coordinate form you can add/subtract then directly: >> >>{1,2}+(3,4} >> >>produces >> >>{4,6} >> >>Regards, >> >>David Bailey >