28 Mar

File:Aliasing between a positive and a negative frequency.png

typo
← Older revision
Revision as of 12:09, 28 March 2013
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=={{int:filedesc}}==

=={{int:filedesc}}==

{{Information

{{Information
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|description={{en|1=This figure depicts two complex sinusoids, colored gold and cyan, that fit the sames sets of real and imaginary sample points. They are thus aliases of each other, when sampled at the rate indicated by the grid lines. The gold-colored function depicts a positive frequency, because its real part (the cos function) leads its imaginary part by 1/4 of one cycle. The cyan function depicts a negative frequency, because its real part lags the imaginary part.}}
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|description={{en|1=This figure depicts two complex sinusoids, colored gold and cyan, that fit the same sets of real and imaginary sample points. They are thus aliases of each other when sampled at the rate (f_s) indicated by the grid lines. The gold-colored function depicts a positive frequency, because its real part (the cos function) leads its imaginary part by 1/4 of one cycle. The cyan function depicts a negative frequency, because its real part lags the imaginary part.}}

|date=2013-03-27 01:09:45

|date=2013-03-27 01:09:45

|source={{own}}

|source={{own}}
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sam_per_sec = 1;

sam_per_sec = 1;

T = 1/sam_per_sec; % sample interval

T = 1/sam_per_sec; % sample interval
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dt = T/20; % resolution of plot is 20 times better than sample rate
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dt = T/20; % time-resolution of continuous functions

cycle_per_sec = sam_per_sec/8; % sam_per_sec = 8 * cycle_per_sec (satisfies Nyquist)

cycle_per_sec = sam_per_sec/8; % sam_per_sec = 8 * cycle_per_sec (satisfies Nyquist)

http://commons.wikimedia.org/w/index.php?title=File:Aliasing_between_a_positive_and_a_negative_frequency.png&diff=93437550&oldid=93399503