Fourier Analysis

[Blair Zajac]

Trying to perform a fourier transform to get a frequency spectrum.

Running excel 2004 Mac.

I don't know whether I am making a format mistake, or what, but it appears
that my caclulations are being rejected because of my data.

Without going into the matter of windowing, I should be able to have either
and/or both begining values equal to zero. As far as I know, it is legimate to
have the data that you want to transform that way, especialy when you
window data to minimize line broadening.

However, either I don't understand the formating, or, as I suspect, the
software thinks that it knows more than I do regard to this matter. Not that I
have never made any mistakes

For those that don't do these calculations on a regular basis, you access the
transform under tools, data analysis.

I'd like to know whether I am doing something wrong before I go to
Microsoft to tell them I don't like software that it thinks that it knows more
about certain items than I do.

If you have any insight, I'd be pleased it you would e-mail me, in addition to
posting to this newsgroup.

Thanks

Blair Zajac
(e-mail address removed)

 

[Dana DeLouis]

Hello. I'm am not sure I understand your problem.

Since I don't know, I'll offer a guess.

When you say "Format" mistake, it sounds like you might be working with
Complex data. Excel can work with a text number like 3 ('3 entered as text,
and not as a number 3). However, make sure that the other text cells don't
have an invalid character that is preventing Excel from using this text
number as a number. Excel will assume that a text number with a missing "i"
or "j" term has a zero Imaginary component. You may want to convert these
text numbers with no imaginary part to actual numbers for debugging.

My second guess is that your complex numbers are not formatted correctly.
To get an example of a correct complex number, enter the following in a
cell. Make sure all complex numbers follow this format...

=COMPLEX(3,4)
or
=COMPLEX(3,4,"j")
and/or both begining values equal to zero.

I am not sure what you mean by beginning value? If you mean you want to
enter zero for both the Real & Complex number, either of the following work
for me. Here, the first 0 is a text zero, entered by '0. Again, either of
these should work.

3
0
0+0i
0i

HTH
Dana DeLouis


Trying to perform a fourier transform to get a frequency spectrum.

Running excel 2004 Mac.

I don't know whether I am making a format mistake, or what, but it appears
that my caclulations are being rejected because of my data.

Without going into the matter of windowing, I should be able to have either
and/or both begining values equal to zero. As far as I know, it is legimate
to
have the data that you want to transform that way, especialy when you
window data to minimize line broadening.

However, either I don't understand the formating, or, as I suspect, the
software thinks that it knows more than I do regard to this matter. Not that
I
have never made any mistakes

For those that don't do these calculations on a regular basis, you access
the
transform under tools, data analysis.

I'd like to know whether I am doing something wrong before I go to
Microsoft to tell them I don't like software that it thinks that it knows
more
about certain items than I do.

If you have any insight, I'd be pleased it you would e-mail me, in addition
to
posting to this newsgroup.

Thanks

Blair Zajac
(e-mail address removed)