@marc sancandi 

I am busy until the end of this month and did not get the chance to go though the code in detail. I observed that there are some examples but they are based on two independent variables and my problem is based on three independent variables. I wanted to plot a function such as w = f(v, x, y, z).

@marc sancandi 

Thanks for helping. But I have 10^5 data points and these were generated from three variables x, y, and z. I want to plot data points given x, y and z value, where x, y and z are axes of a triangle. This is what I am looking for.

http://www.originlab.com/doc%5Cen/UserGuide/Ternary_Contour/TernaryContour_1.png

@marc sancandi 

I am expected to plot similar to the image as shown in link.

http://www.originlab.com/doc%5Cen/UserGuide/images/Ternary_Contour/TernaryContour_1.png

@marc sancandi 

Thanks for the posting. This will draw triangle only.

I have more than 10,000 points, how I am going to plot on this triangle?

@Markiyan Hirnyk 

Thanks for your help.

@Markiyan Hirnyk 

I tried but did not get any.

@Markiyan Hirnyk 

Thanks for an example.

How can I store the value of x at t=1 in a variable? Something like  

xValue:= x(1)

@Markiyan Hirnyk 

Thanks for the reply. I have already checked but no clue how to get value of x and y at say t=5 and store into file. can you write command for this?

@Markiyan Hirnyk 

Thanks for helping.

But how to find the period of f(t) using code?

How to find the value of n=29?

@Markiyan Hirnyk 

Here is my code:

restart: with(OrthogonalExpansions):
f := proc (t) options operator, arrow;3*cos(2*t+Pi/4)-2*sin(3*t-Pi/3)-exp(I*t/4) end proc;
Exp := FourierSeries(f(t), t =0 .. 12*Pi, n, series = exponential); n := 5;
Exp := value(Exp);

How to find period? and extarct the coefficients?

@Markiyan Hirnyk 

Lets say, I have f(t) = 3cos(2t+Pi/4)-2sin(3t-Pi/3)-exp(jt/4).

(1) How to find the period of f(t)?

(2) Find the Fourier Series representation of f(t) (a) Exponential Form  (b) Trigonometric Form

(3) How to find the Fourier Series coefficients of f(t) for exponential form

@acer 

Thanks.

@Markiyan Hirnyk 

Yes, this is what I am trying to use. Let me work it out myself, otherwise I will post the question.

The another package i mentioned above, has come other stuff and I would like to check. Is there any way, I can download this package.

@Markiyan Hirnyk

Thanks. I have this one you mentioned above, but don't know how to find Fourier coeefficients from exponential form of the series.

I am refering to this package. where can I download?

@Kitonum 

Thnaks for helping. Next week, I will be working on different other graphs and will post most more questions if any.