Lowyat.NET: Latest topics by Krevaki

Files missing but space still used.

Krevaki — Tue, 08 Oct 2013 20:30:13 +0800

Okay guys, going to need some serious help with this one.

My laptop was working fine this morning, but then in the evening, I turned it on and my files are missing. This includes files in My Documents, My Pictures, Downloads, Desktop, etc. I looked at the free space of Local Disk C but it doesn't seem that those files were deleted, since the space looks the same as before. Could a virus somehow did something? Forgot to add that I tried Folder Options but that did not work out.

The programmes on C looks fine (I have not tested them and I dare not), and D looks untouched.

I am scared to even turn it on now. Any suggestions?

Matlab help

Krevaki — Mon, 22 Apr 2013 11:54:09 +0800

Any Matlab experts here?

I am trying to plot the graph of Maclaurin series from degree 1 to N, where N=[4,10].
The code I wrote is:

CODE

x=-2*pi:0.01:2*pi;
y=cos(x);
for N=4:1:10
M_N=1;
for n=1:1:N
M_N=M_N+((-1^n)*(x.^(2*n)))/factorial(2*n);
end
hold on
plot(x,y,x,M_N)
axis([-2*pi 2*pi -3 3])
hold off
end

But then when I run it, it will only give the series for n=1. I have been trying to crack this all morning. What exactly am I missing here?

Noob C++ question

Krevaki — Thu, 28 Feb 2013 16:29:41 +0800

Hello sifus and gurus, I'm just starting out on C++ and I'm new to programming.
So please go easy on me. Anyway, below is a simple exercise that I'm doing.

Question:
You buy a new car for $ 80,000.00. You take a 90% hire purchase loan for 9 years (108 months) at the annual interest rate of 3.0%.
Calculate the monthly payment and interest amount. Your program should display those calculations and other values that you find interesting to the screen.

What I did was:

CODE

double Car_Price = 80000.00;
double Hire_Purchase_Loan_Percentage = 0.9;
double Annual_Interest_Rate = 0.03;
double Repayment_Period_in_Years = 9;
double Repayment_Period_in_Months = 108;
double Loan_Taken;
double Amount_to_be_Repaid;
double Monthly_Payment;

Loan_Taken = Car_Price*Hire_Purchase_Loan_Percentage;
Amount_to_be_Repaid = Loan_Taken+Loan_Taken*Annual_Interest_Rate*Repayment_Period_in_Years;
Monthly_Payment = Amount_to_be_Repaid/Repayment_Period_in_Months;

cout <<"Car Price = 80000.00\n";
cout <<"Hire Purchase Loan Percentage = 0.9\n";
cout <<"Annual Interest Rate = 0.03\n";
cout <<"Repayment Period in Years = 9\n";
cout <<"Repayment Period in Months = 108\n";
cout <<"Loan Taken=";
cout <<Loan_Taken;
cout <<"Amount to be Repaid=";
cout <<Amount_to_be_Repaid;
cout <<"Monthly Payment=";
cout << Monthly_Payment;

I don't really like what I did. So my questions are:
1. Would it be better (neat and refined) if I use

CODE

double a = 80000.00; //Car Price

instead of

CODE

double Car_Price = 80000.00;

?
2. What are the differences between all the float and double? Seems to me that they only affect the space taken and degree of accuracy.
3. How do I make it round off to XXX.XX?

Many thanks in advance.

[WTA]At what point does

Krevaki — Tue, 15 Jan 2013 20:54:13 +0800

Okay, the story goes like this:

My neighbours saw an advertisement online saying beagle puppies for adoption. They went to the place, had their eyes set on one puppy, and the owner asked for RM1600.

Now if you were to ask for two or three hundred Ringgit as compensation I would understand, but RM1600? To me, this smells like a backyard breeder trying to make a quick buck. What do all of you think? Adoption or selling? Reasonable or daylight robbery?

Extra info on puppies:
Claim to be pure breed beagle.
Around two months old.
Not vaccinated.
No neutering/spaying whatsoever.

An Engineer's View On Three Phase Power System

Krevaki — Sun, 16 Dec 2012 09:49:55 +0800

Engineers, allow me to pick your brain on one thing.

The question:
As an engineer (especially electrical and/or electronics), what can you say about the voltage of a three phase power system? And what is your conclusion from it?

Do pardon me if this troubles you.

[Car Stolen]

Krevaki — Sun, 09 Sep 2012 15:50:09 +0800

Car: Naza Ria
Plate : WLN 7740
Colour: Sandstone
Last seen: Sri Petaling
Others: The rear end (the hatch) is dented

Please help keep an eye out.

Changing University/Course: A Guide

Krevaki — Fri, 20 Jul 2012 09:51:59 +0800

At the time of writing, most of you should have agreed to your IPTA offer. If not, do it.

Before I start, I want you to take some time and reflect on this statement: "In life, you do not always get what you want." Should you be grateful that you got an offer? Should you be asking for a transfer? Should you be whining about how you did not get what you want?

RAYUAN on UPU website is for those who failed to secure an offer.

Transfer to a Different University
To do this, you write a letter to the dean of the faculty of the university with the course that you desire. Write about why you deserve to get in, why you want that particular course, what differences your presence can bring. Include all relevant supporting documents instead of throwing in everything, and preferably arrange in order of importance. If the dean says yes, you can register straight away.

Intra-University Course Change
The first way is after your orientation week, send an appeal letter (with supporting documents) to the dean of the faculty with your desired course. You can even get a supporting letter from the dean of the of your original faculty approving you to change (assuming the two courses are in different faculties), but this is optional.

The second way has a high chance of succeeding. After you have studied for one semester, submit an application letter together with your first semester result to the dean of the faculty with your desired course. If your application does not get approved, try again after every semester until it gets approved. Although, most people just give up after 2 or 3 semesters.

Through UPU Again
Wait until the next year, when UPU starts accepting applications again and you apply using the same STPM result you got under the category Diploma (not current STPM). Take note that you will be competing with a new batch, so be careful of your choices.

That Kind of Cable
You can try to get help from your local people's representative/political parties/politicians, but the best kind of cable is the kind within the upper echelons of university staff.

Change University, but Same Course
This is not for those who just got their UPU offer. This is for those who did some time at their university (say 1 year), and decide to change to another university for reasons such as closer to home. For this, you need to go to the office and inquire about the procedures. But there is no need to worry about starting over again as it is possible to get exemptions.

Mathematics for Future Engineers

Krevaki — Mon, 18 Jun 2012 18:25:49 +0800

Hi all, this topic is created to help those who decide to go down the Engineering path but aren't exactly confident when it comes to Mathematics. Here, we show you the kind of Mathematics that you may encounter so that you can have a rough idea as well as a head start. However, we defer the discussion of their applications in Engineering problems to your lecturer.

We are just starting out so we are lacking from many aspects. Therefore, we would like to ask all those who read our notes to inform us of any error they find as well as provide us with advice on how to make our notes better. We would really appreciate that.

http://uploaded.net/file/zfpyzj3i

Topics covered:
Mathematical Proof: Mathematical Induction
Coordinate Systems: Polar Coordinates, Circular Coordinates, Spherical Coordinates
Functions and Limits: Squeeze Theorem, l'Hopital's Rule, Method of Bisections
Differentiation: Rolle's Theorem, Mean Value Theorem, Linear Approximations
Integration: Reduction Formula, Improper Integral, Midpoint Rule, Simpson's Rule, Arc Length, Surface Area
Power Series: Maclaurin Series, Taylor Series, Taylor's Theorem
Fourier Series: Dirichlet Conditions, Fourier Convergence Theorem, Half Range Fourier Series
Multi Variable Differentiation: Partial Derivatives, Higher Order Partial Derivatives, Increments and Differentials, Chain Rule, Gradient, Directional Derivatives, Extrema, Extreme Value Theorem, Lagrange Multipliers
First Order Differential Equation: Integrating Factor, Power Series Approximation, Euler's Method
Second Order Differential Equation: Homogeneous, Nonhomogeneous, Power Series Solution

Confusion over NUS admission.

Krevaki — Thu, 26 Apr 2012 21:39:09 +0800

Hi all, new here. All right, straight to topic:

1. I receive an email from NUS congratulating me, saying I made it into FASS, but that is actually my fifth choice. So I'm mulling whether to accept or not (dateline: 4 of May 2012). I'm worried that UPU offer (comes out around July, I believe?) may not be very good.

2. If I accept their offer, will they allow me to change course or something? Maybe after 1 semester? (I was vying for Mechanical Engineering.)

3. Arts and Social Sciences cover so much. Do they ask you what you're going into during admission? Any suggestions on what subjects to take up?

4. The appeal form on their website (which will be available by 23 of May 2012) is actually for those who didn't get NUS offer, right?

5. I have also applied for ASEAN scholarship, but no news on that whatsoever. Anyone know when you will hear from them? I need to secure funding as my family is not loaded.