• To: mathgroup at smc.vnet.net
• Subject: [mg52083] Re: [mg52023] Re: Adding Vectors -- Newbie help please
• From: yehuda ben-shimol <yehuda at cse.bgu.ac.il>
• Date: Wed, 10 Nov 2004 04:45:23 -0500 (EST)
• References: <cmfc9b\$7k3\$1@smc.vnet.net> <cmhut5\$ppb\$1@smc.vnet.net> <200411070604.BAB18090@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```I can do 1+1=2 much faster then a typing it on a calculator
and probably I can multiply 100*333 faster on a calculator then on
Mathematica (assuming that the Kernel should be uploaded)
But that seems to be all (this is only and example).
If you would take few minutes to look at the list or at the Mathematica
book  you probably would find out that you can do MUCH MUCH more with
it would be).
I assume that you come for the EE or closely related field due to the
units  in your simple question. If you keep using Mathematica you will
find out that you can use it for engineering tasks much better than
other "competing" scientific softwares.
So, PLEASE, next time just focus on what you don't know and we will do
In addition, another good place for students questions is at
http://forums.wolfram.com/student-support/list/
A complete solution for your question is given at R. Maeder's book
"Programming in Mathematica"
good luck
yehuda

motz art wrote:

>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
>>
>>{1,2}+(3,4}
>>
>>produces
>>
>>{4,6}
>>
>>Regards,
>>
>>David Bailey
>>
>>

```

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