| T O P I C R E V I E W |
| slammu123 |
Posted - 06/13/2003 : 10:52:56 AM
Hi
I want to add a phase factor i.e exp(ix) in my code.But it says the variable 'i' is not declared. |
| 10 L A T E S T R E P L I E S (Newest First) |
| Mike Buess |
Posted - 06/17/2003 : 1:39:56 PM
I think the complex vector functions GetReal(), GetImaginary() and so on came out in one of the service releases, but I don't recall off hand which one. (The latest is SR4.) If your PC is connected to the internet run Help->Check for Updates and download&install whatever is offered. You'll probably have to run it several times to get caught up.
Alternatively, you can use the non-complex method I suggested in my earlier posts. Namely, replace these lines...
vector<complex> vf; // declare a complex output vector
vf = dx*dy*exp((dA+dB)*1i); // your function
vf.GetReal(dRe); // extract real data
vf.GetImaginary(dIm); // extract imaginary data
vf.GetAmplitude(dAmp); // extract amplitude data
vf.GetPhase(dPh); // extract phase data
with these lines...
dRe = dx*dy*cos(dA+dB);
dIm = dx*dy*sin(dA+dB);
dAmp = abs(dx*dy);
dPh = angle(dRe,dIm);
It's somewhat less efficient but works nonetheless.
Mike Buess
Origin WebRing Member
Edited by - Mike Buess on 06/17/2003 2:06:53 PM |
| slammu123 |
Posted - 06/17/2003 : 12:58:14 PM
Hi
I tried this code but it says that "GetReal" is not defined or does not have a matching prototype.
|
| Mike Buess |
Posted - 06/16/2003 : 5:15:27 PM
As you've probably guessed by now, a complex function will generate two output datasets. Actually, there could be four (real, imaginary, amplitude and phase). Since you haven't said which are meaningful to your analysis I'll show you how to get them all.
1> First you must set up your worksheet such that it has the input columns A, B, X and Y as well as the output columns Re, Im, Amp and Ph.
2> Double click on each of the output columns and set its format to 'numeric' instead of 'text+numeric'. (The following code crashed Origin until I did that.)
3> Use the following code in an Origin C function.
WorksheetPage wpg = Project.Pages();
string wksName = wpg.GetName(); // get wks name
Dataset dA(wksName + "_A"); // declare datasets
Dataset dB(wksName + "_B");
Dataset dx(wksName + "_X");
Dataset dy(wksName + "_Y");
Dataset dRe(wksName + "_Re");
Dataset dIm(wksName + "_Im");
Dataset dAmp(wksName + "_Amp");
Dataset dPh(wksName + "_Ph");
vector<complex> vf; // declare a complex output vector
vf = dx*dy*exp((dA+dB)*1i); // your function
vf.GetReal(dRe); // extract real data
vf.GetImaginary(dIm); // extract imaginary data
vf.GetAmplitude(dAmp); // extract amplitude data
vf.GetPhase(dPh); // extract phase data
4> Make sure that column A is set as X and the rest Y.
5> Select the output columns you want to plot and choose a plot type from the Plot menu.
Hope that helps.
Mike Buess
Origin WebRing Member
Edited by - Mike Buess on 06/16/2003 5:15:59 PM |
| slammu123 |
Posted - 06/16/2003 : 1:15:53 PM
I want to plot the expression
F=x*y*exp(i*(a+b)) with respect to a .
here x,y,a,b, are datasets and exp(i*(a+b))refers to a complex number.
How do I do that?
|
| Mike Buess |
Posted - 06/13/2003 : 6:27:17 PM
That will again require two output columns... one for the real part, 1+cos(a+b), and the other for the imaginary part, sin(a+b).
WorksheetPage wks = Project.Pages();
string wksName = wks.GetName(); // get name of active worksheet
Dataset dA(wksName + "_A"); // eg, data1_A
Dataset dB(wksName + "_B");
Dataset dG(wksName + "_G");
Dataset dH(wksName + "_H");
dG = 1 + cos(dA+dB);
dH = sin(dA+dB);
Mike Buess
Origin WebRing Member |
| slammu123 |
Posted - 06/13/2003 : 5:51:20 PM
I would like to add another column for example:
g=1+exp(i*(a+b))
where a and b are different columns in the worksheet and I want to put them in the column named g in the same wokrsheet.
|
| Mike Buess |
Posted - 06/13/2003 : 3:41:49 PM
You want to multiply each row of a column by exp(ix)? Worksheet cells will not hold complex data so you'll have to create two columns (real and imaginary) for the results. Assuming you're operating on the first column of the active worksheet here's the easiest way to put the results in columns 2 and 3. It makes use of the relationship exp(ix) = cos(x) + isin(x) ...
void test(double x)
{
Worksheet wks = Project.ActiveLayer();
Dataset dd(wks,0); // first column. (Origin C uses zero based indexing.)
Dataset dRe(wks,1); // second column
Dataset dIm(wks,2); // third column
dRe = dd * cos(x);
dIm = dd * sin(x);
}
Mike Buess
Origin WebRing Member |
| slammu123 |
Posted - 06/13/2003 : 2:50:32 PM
what should i do if i want to calculate the phase factor for each of the values in a dataset and put the result in another column of the worksheet? |
| cpyang |
Posted - 06/13/2003 : 12:58:40 PM
Or you can multiply by 1i, like
void test(double x)
{
out_complex("exp(ix)=",exp(x*1i));
}
CP
|
| Mike Buess |
Posted - 06/13/2003 : 11:15:09 AM
A complex argument must have a real and imaginary part.
void test(double x)
{
complex cc(0,x); // real=0, imag=x
out_complex("exp(ix)=",exp(cc));
}
test(3);
exp(ix)=-0.989992+0.141120i
Mike Buess
Origin WebRing Member
Edited by - Mike Buess on 06/13/2003 11:17:00 AM |
