|
Ah, then, it's OK. I didn't remember the definition.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
|
|
|
|
|
MarkBrock wrote: -> i = 6>0 / 565.685>0.785
I think the V phase is wrong. It should be PI/2 instead of 0.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
|
|
|
|
|
Yes I think so too...
And when the sunlight hits the olive oil, don't hesitate.
|
|
|
|
|
It's comforting: I don't remember a lot of that stuff...
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
|
|
|
|
|
Yup that was it!
t=1 and t=0.1 both worked so im satisfied with that.
<br />
<br />
-7.5*e^-2000t + 10.61*sin(w*t + 0.785) mA<br />
<br />
<br />
-> L*(di/dt) + R*i = V*cos(w*t)<br />
<br />
L = 0.2<br />
R = 400<br />
i(t) = -7.5*e^-2000t + 10.61*sin(2000*t + 0.785) mA<br />
i'(t) = 15*e^-2000t + 21.22*cos(2000*t + 0.785)<br />
V = 6<br />
<br />
-> 0.2*(15*e^-2000t + 21.22*cos(2000*t + 0.785)) <br />
+ 400((-7.5*10^-3)*e^-2000t + (10.61*10^-3)*sin(2000*t + 0.785))<br />
= 6*cos(2000*t)<br />
<br />
Let t = 1<br />
<br />
-> 0.2(0 -19.46) + 400(0 + (9.8677*10^-3)) = 6cos(2000)<br />
<br />
-> -3.893 + 1.6898 = -2.2<br />
-> -2.2 = -2.2<br />
<br />
Horray! <br />
<br />
Thankyou so much for your help!
Cheers,
|
|
|
|
|
You're welcome.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
|
|
|
|
|
Did you work it out?
And when the sunlight hits the olive oil, don't hesitate.
|
|
|
|
|
Yup that was it!!!
t=1 and t=0.1 both worked so im satisfied with that.
<br />
<br />
-7.5*e^-2000t + 10.61*sin(w*t + 0.785) mA<br />
<br />
<br />
-> L*(di/dt) + R*i = V*cos(w*t)<br />
<br />
L = 0.2<br />
R = 400<br />
i(t) = -7.5*e^-2000t + 10.61*sin(2000*t + 0.785) mA<br />
i'(t) = 15*e^-2000t + 21.22*cos(2000*t + 0.785)<br />
V = 6<br />
<br />
-> 0.2*(15*e^-2000t + 21.22*cos(2000*t + 0.785)) <br />
+ 400((-7.5*10^-3)*e^-2000t + (10.61*10^-3)*sin(2000*t + 0.785))<br />
= 6*cos(2000*t)<br />
<br />
Let t = 1<br />
<br />
-> 0.2(0 -19.46) + 400(0 + (9.8677*10^-3)) = 6cos(2000)<br />
<br />
-> -3.893 + 1.6898 = -2.2<br />
-> -2.2 = -2.2<br />
<br />
Horray! <br />
<br />
Thankyou so much for your help!
Cheers,
|
|
|
|
|
Good!
MarkBrock wrote: Thankyou so much for your help!
No problem.
And when the sunlight hits the olive oil, don't hesitate.
|
|
|
|
|
MarkBrock wrote: ...and Z is impedance.
Back when I took electronics courses, we used R for resistance.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
DavidCrow wrote: Back when I took electronics courses, we used R for resistance.
We still do; impedance is complex: Z = R + jX. 
"A Journey of a Thousand Rest Stops Begins with a Single Movement"
|
|
|
|
|
Thanks for the refresher (AC vs. DC). It's been a long time.
"Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
Hi all,
I appologize if this is an inappropriate place to ask,
but I would appreciate if someone could help me with
the following issue.
I need to define an algebraic group (with prime
order), and define a method to transform strings of
bits, into elements of this group.
Could anyone, target me to some literature, or
programming libraries, that illustrate how to achieve
this?
Thank you in advance.
|
|
|
|
|
I've created a polygon component for a small vector graphics section in my program. I have a function where the user can convert a line section to a cubic bezier.
My question is: I would like the control points to initially bend the curve to the outside of the polygon. Mathematically speaking, how do I determine what coordinates are inside the shape or outside the shape?
If you could rent a programmer a hour and a half for a dollar and a half, how much would he charge for 10 hours?
|
|
|
|
|
If you want to determine points inside and outside a polygon, this[^] should do the trick! Make sure you handle points that lie directly on a vertex.
|
|
|
|
|
This is a homework question. If your against helping students, I understand.
<br />
<br />
Given the differential equation :<br />
<br />
dy/dx + 2y = -5, y(0) = 3<br />
<br />
Solve using Newton's first order numerical method, taking sufficient steps to estimate y when x = 2.<br />
<br />
I can't find any examples on how to solve the equation using this method.
It would be appreciated if someone showed me how to do this, or pointed me to a useful example.
Cheers,
|
|
|
|
|
The numerical recipes book(s) has been a God-send for many of us. It was originally for Fortran, then translated to (a rather clunky, but functional) C. The really great thing is that they do a good job of explaining the algorithms. I have, for the most part, just used their explanations and written my own code.
Here's a link to their older versions that you can read on-line.
http://www.nrbook.com/a/[^]
You can also find their most recent versions at www.nr.com
The book will explain the Newton method, and have examples of it's use.
David
---------
Empirical studies indicate that 20% of the people drink 80% of the beer. With C++ developers, the rule is that 80% of the developers understand at most 20% of the language. It is not the same 20% for different people, so don't count on them to understand each other's code.
http://yosefk.com/c++fqa/picture.html#fqa-6.6
---------
|
|
|
|
|
Thanks! 
|
|
|
|
|
MarkBrock wrote: I can't find any examples on how to solve the equation using this method.
You obviously haven't looked. 
Doing my part to piss off the religious right.
|
|
|
|
|
Sure I have,
I read this, searched Google, and found "Code Project Math Forum: Mathematics and Algorithms discussions - Full of people who love to solve differential equations"...  .
|
|
|
|
|
MarkBrock wrote: searched Google
I searched Google[^] and the material David referenced, albeit in a different location, popped up on the first page. Actually, two different versions of that book. The implementations in the language specific versions of "Numerical Recipes" suck since they're crappy direct, probably machine generated, translations of the original FORTRAN.
Doing my part to piss off the religious right.
|
|
|
|
|
In case anyone cares...
I found out that Newton's first order numerical method is actually Euler's method.
y(h) = y(0) + h*(dy/dx).
It is a way of estimating the solution of a differential equation.
Cheers,
|
|
|
|
|
Hello!
How do I create type in HTML VBScript or/and javascript which was same as System.Decimal (in .NET Framework)?
Double is not comfortable type, because it saves only 15 digits the whole digits are lost.
Thanks for suggestions!
|
|
|
|
|
There is a int array consists of 1001 elements. Inside it, only two element's values are equal.
I mean that there are two items have the same value, and the other items are different.
Design a algorithm according to the following commands:
1 every item of the array can only be visited once
2 find out the same value
many thanks
|
|
|
|
|
Good luck.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
