Saving complex numbers?
Hello all,
I need to save a calibration file...simple enough, but my calibration file is an array of complex numbers. I tried to find the proper precession (ie. %.3f) but I couldn't locate the precession extension for complex numbers. When I try to save the array I loose all of my complex numbers...so how do you save an array with complex numbers?
Thanx
Azazel
Azazel
Pentium 4, 3.6GHz, 2 GB Ram, Labview 8.5, Windows XP, PXI-5122, PCI-6259, PCI-6115
Hi,
You can try the attached VI which is a modified version of Write to Spreadsheet File function so that you can now write complex numbers to a spreadsheet or text file.
Regards,
Ankita
Attachments:
Write to spreadsheet file Complex.vi 59 KB
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I don't think there is a direct way of converting a complex number to a
string, so when you convert the array to a spreadsheet string, the
numbers would be converted to real data.
However, you could try separating the real and imaginary parts using the
"Numeric: Complex to Re/Im" function, and then store these - either in
separate files or in adjacent columns/rows in the same file. Then, when
you read in the data again, use the "Numeric: Re/Im to Complex" function
to put the two "halves" together.
If you actually want Excel to interpret the numbers as imaginary, then
you'll probably want to create a string for each complex number of the
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"String:Format into String" with 2 numeric inputs and the format string
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Reading the data back into Labview then would require splitting the
string into the 2 pieces by using "Stringcan from String" with 2
numeric outputs (smae precision as original numbers specified by the 2
Default Value inputs) and the same format string "%f+%fi", and then using
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Paul
Biz wrote:
> Having trouble converting array to spreadsheet string, storing the
> file and coverting back to array with complex numbers
>
> I am working with a network analyzer. I have arrays made of 5 columns
> the first consisting of an integer and the next four consisting of
> complex numbers. I am converting the array into a spreadsheet string
> and then saving the file using the write characters to a file VI. That
> seems to work well as when I open the file in Excel all the data is
> there. However when I try to reverse the process, open file and
> convert back to array, I loose some of the data. Specifically the
> imaginary parts of my complex numbers are all going to zero. I have
> narrowed down the problem to be in the conversion from spreadsheet
> string to array and vice versa. I think the problem may be with the
> 'format' input to the VI. I do not have an adequate resource for this
> so I am not sure what to put in to accomplish my task. Any takers?
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class Complex
private double realPart, imaginaryPart;
public Complex()
realPart = 0.0;
imaginaryPart = 0.0;
public static void main(String [] args)
Complex c;
double res;
c = new Complex();
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public double get_realPart()
return realPart;
public double get_imaginaryPart()
return imaginaryPart;
public void addComplexNum(Complex n1, Complex n2)
realPart = n1.get_realPart() + n2.get_realPart();
imaginaryPart = n1.get_imaginaryPart() + n2.get_imaginaryPart();
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Screen.message("-----------------------------------------------");
Screen.newline(2);
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realPart = n1.get_realPart() - n2.get_realPart();
imaginaryPart = n1.get_imaginaryPart() - n2.get_imaginaryPart();
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Screen.message(" - " + imaginaryPart + "i");
Screen.newline();
Screen.message("-----------------------------------------------");
Screen.newline(2);
public void multiplyComplexNum(Complex n1, Complex n2)
realPart = n1.get_realPart() * n2.get_realPart();
imaginaryPart = n1.get_imaginaryPart() * n2.get_imaginaryPart();
Screen.message("-----------------------------------------------");
Screen.newline(2);
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Screen.message(" * " + imaginaryPart + "i");
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Screen.newline();
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Try doing something a bit more like this:
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read another float from the keyboard
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Complex complex1 = new Complex();
complex1.realPart = first number from above;
complex1.imaginaryPart = second number from above;
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then add the numbers together
Complex complexSum = new Complex
complexSum.addComplexNum(complex1, complex2)
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Need help with complex numbers ..
Hi!
Just want to check if i got it right - if anyone could pls confirm:
public void divComplex(Complex a, Complex b)
x = ((a.x * b.x) + (a.y * b.y))/((b.x * b.x) + (b.y * b.y));
y = ((a.y * b.x) + (a.x * b.x))/((b.x * b.x) + (b.y * b.y));
public void multComplex(Complex a, Complex b)
x = ((a.x * b.x) - (a.y * b.y));
y = ((a.x * b.y) + (a.y * b.x));
where:
protected double x;
protected double y;
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Is this correct?
SiwFor the division you have,
a/b = a*b'/b*b' = a*b'/|b|
|b| = (b.x + ib.y)*(b.x - ib.y) = b.x*b.x + b.y*b.y
a*b' = (a.x + ia.y)*(b.x - ib.y) =
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There seems to be a slight mistake in the imaginary part (y).
y = a.y*b.x - a.x*b.y / (b.x*b.x + b.y*b.y);
But don't take my word for it. It's been ages since I did complex numbers -:)
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