mstevens

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10 years, 165 days

MaplePrimes Activity


These are replies submitted by mstevens

@dharr Thanks for the thorough examples.

 

@acer Sorry about that, I copied and pasted it from 2d worksheet mode. 

Yes using the Physics:-diff() function works. I am puzzled as to why the diff and partial diff operators from the pallete gives this error! Quite odd/inconsistent behavior!

@tomleslie Thanks. I knew there had to be a way.

@tomleslie It can show appropriate approximate values of a nyquist plot when the results of the transfer function go to infinity on either the real or imaginary axis. See (10) Nyquist Stability Criterion, Part 2 - YouTube at approximately 15:34.

@mmcdara I am a math and Maple novice. Can you explain why your solution is more flexible? I am just trying to learn. I spent hours trying to come up with what you all came up with in, essentially, two lines.

 

@Preben Alsholm 

Yes, the continuation was it. I was able to do that part. The key here for me was the unapply(). 

Thanks again!!

@Preben Alsholm Thanks, this is exactly what I wanted to do. With respect to x vector I want x to be a vector of discrete points such as x := Vector([seq(0 .. 5, 0.1)]).

Again. Thanks.

Melvin

@Carl Love Thank you. This is exactly what I wanted.

@vv Are you kidding me?!? Ummm hold on a sec. let me go to my cave and grab my stone tablet, chisel and mallet. Your comments make no sense, especially since Maplesoft lauds Maple's presention capabilites.

 

 

 

 

@acer Take a look at this example.pdf.

 

There should be a way to mix notations. e.g. polar(1,pi/2)+(3+I*5). or (1<pi/2)*(1+I) or polar(7,pi/3)+3<pi/2 or 6<23degrees-(4+6I) ... etc.  this seems to be overly difficult in Maple.

There needs to be the ability to do conjugate(`&angle;`(1, 25)).

As for you direct question about "or", it is ok to output mag<angle but there should be a right-click option to convert it to all other formats of a complex number. In fact all of the stuff in the right-click Complex Maps menu should be there. A phasor is  complex number/a vector in the complex plain

I don't know that I have the time to do this myself. No time to learn to program Maple at the moment. But say something like:

        polar(1,pi/2)+ I

which is 2I , should be built into Maple. The above gives me polar(1, (1/2)*Pi)+I ... that is ridicoulous.

 

@acer Phasors are just  representations of frequency invariant sinusoids in the imaginary plane a+jb, also can be denoted by magnitue<angle in polar form . I am not sure about how what coded is differnt because I have not had time to thorough use it. It seems though that I did something like 1<angle and then did a conversion on it and the something went wrong with the conversion. My apologies for not being able to detail. I am pretty busy right now.

Succinctly, the polar function performs all opertions perfectly. I just would like to be able to type mag<ang for a+jB. and I would like for maple to display the results of all complex operations in the form of mag<ang or a+jb. Note electrical engineers use j instead of i because i is most commonly used in EE for the current in a circuit.

So ideally mag<angle => polar(mag,angle); where angle is in rads and the all operations +-/* do polar() operator polar() and then display the results in a+jb or mag<angle. Should be quite simple.

I am not saying what you have written is not good; but if you are going to call it "Phasors" then  all operations should adhere to Phasor notations/operations.

My gripe was I love Maple as a tool but I just cannot work with it. I should not have to learn to program Maple to do something so simple. It is the same with using Units. The Units feature in Maple is powerful. But you have to get a degree in Maple in order to be able to use them. For example in Power Engineering we use the term terms like "a load consumes 300 MVA power factor (pf) .8 lagging. 

In Mathcad, MVA is not a unit but V and A is so I define MVA:=10^6*V*A amd now I can just type 300*MVA and the MVA is highlighted in blue as a unit. also I can make lagging a unit by defining lagging:=1. Then it is highlighted in blue as a unit so now I can do 300MVA<acos(pf)*lagging = and Mathcad displays 300*10^6<.644*W then I can type *MVA*lagging and it displays 300<.644*MVA*lagging and if I want it in degrees that is a simple menu selection. ...Even something as simple as unit creation is quite involved in Maple.

Again I need to enroll in a 4 year program to learn to code Maple to do this. Sure it can do it but Maplesoft should build this functionality into  the program. I should not have to become a Maple coder in order to work with Maple. A simple TI 89 calculator can do it a the fraction of the cost of Maple.

Sorry for this rant but I really want to use Maple. It just takes too much time to get anything done in it; primarily because one has to program it to do even the simplest of tasks.

So I have bolded the functionality for which I am searching so as to make it stand out in all this noise I've created.

Melvin

Hmm... Right, I was looking for phasors. I should be able to recode the angle symbol as you have but have it represent phasors. This is so simple in Mathcad. As I really needed to get work done, I justed turned to Mathcad to be productive. I am now going to spend a few hours to see if I can somehow get the same functionality from Maple.

I got all that I needed to get done using Mathcad and it only took a fraction of the time that I have spent searching for a solution in Maple.

Again, I believe Maple is better, and more robust than Mathcad but, while Mathcad is a weaker package, for presentation it can't be beaten. I am electrical engineering grad student. I use the packages for presentation (homework, Power Point presentations and such). I can't put in a presentation polar(345,pi/6)*conjugate(polar(10,.1532) with the answer being displayed in the same format.

In Mathcad I just do 345<pi/6*(10,.153)(with conjugate bar over it) and the answer is then given to me in a + bi then I could select the a+bi and have it displayed as a+bj or as Mag<(angle in degree) or Mag<(angle in rads). Also, I can highlight anything, including the result. It is too simple. In Maple, this seems to be impossible to accomplish. That is horrible considering the power of Maple. This functionality should be built into Maple. Pehaps my attempts have failed because I am only a Maple neophyte.

Melvin

 

When I go towww.mapleprimes.com and in the search box type "phasors" your solution is not listed in the search results. It would be a tremendous help if everyone would tag their posts properly.

I have not tried you solution yet but it looks exactly like what I want. Thanks for taking the time to code it.

Melvin

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