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<span class="path"><a href="index.html">FOSSEE Signal Processing Toolbox</a> >> <a href="section_cc2bc01c47967d47fcf3507a91d572ba.html">FOSSEE Signal Processing Toolbox</a> > fftshift1</span>
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<div class="refnamediv"><h1 class="refname">fftshift1</h1>
<p class="refpurpose">Perform a shift of the vector X, for use with the 'fft1' and 'ifft1' functions, in order the move the frequency 0 to the center of the vector or matrix.</p></div>
<div class="refsynopsisdiv"><h3 class="title">Calling Sequence</h3>
<div class="synopsis"><pre><span class="functionid">fftshift1</span><span class="default"> (</span><span class="default">X</span><span class="default">)</span>
<span class="functionid">fftshift1</span><span class="default"> (</span><span class="default">X</span><span class="default">, </span><span class="default">DIM</span><span class="default">)</span></pre></div></div>
<div class="refsection"><h3 class="title">Parameters</h3>
<dl><dt><span class="term">X:</span>
<dd><p class="para">It is a vector of N elements corresponding to time samples</p></dd></dt>
<dt><span class="term">DIM:</span>
<dd><p class="para">The optional DIM argument can be used to limit the dimension along which the permutation occurs</p></dd></dt></dl></div>
<div class="refsection"><h3 class="title">Description</h3>
<p class="para">This is an Octave function.
Perform a shift of the vector X, for use with the 'fft1' and 'ifft1' functions, in order the move the frequency 0 to the center of the vector or matrix.</p>
<p class="para">If X is a vector of N elements corresponding to N time samples spaced by dt, then 'fftshift1 (fft1 (X))' corresponds to frequencies</p>
<p class="para">f = [ -(ceil((N-1)/2):-1:1)*df 0 (1:floor((N-1)/2))*df ]</p>
<p class="para">where df = 1 / dt.</p>
<p class="para">If X is a matrix, the same holds for rows and columns. If X is an array, then the same holds along each dimension.</p>
<p class="para">The optional DIM argument can be used to limit the dimension along</p></div>
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