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Import.
| author | Daniele Nicolodi <nicolodi@science.unitn.it> |
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| date | Wed, 23 Nov 2011 19:22:13 +0100 |
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| 1 <h2>Description</h2> | |
| 2 <p> | |
| 3 Resampling is the process of changing the sampling rate of data. <a href="matlab:doc('ao/resample')"><tt>Resample</tt></a> | |
| 4 changes the sampling rate of the input AOs to the desired output sampling frequency. LTPDA <a href="matlab:doc('ao/resample')"><tt>resample</tt></a> overloads <tt>resample</tt> function of Matlab Signal Processing Toolbox for AOs. | |
| 5 </p> | |
| 6 <h2>Syntax</h2> | |
| 7 <div class="fragment"><pre> | |
| 8 <br> | |
| 9 b = resample(a, pl) | |
| 10 </pre> | |
| 11 </div> | |
| 12 <h2>Parameters</h2> | |
| 13 <p> The following parameters can be set: | |
| 14 <ul> | |
| 15 <li> <tt>fsout</tt> - specify the desired output frequency (must be positive and integer)</li> | |
| 16 <li> <tt>filter</tt> - specified filter applied to the input, <tt>a</tt>, in the resampling process</li> | |
| 17 </ul> | |
| 18 </p> | |
| 19 <p> | |
| 20 <h2>Examples</h2> | |
| 21 </p> | |
| 22 <p> | |
| 23 2. Resampling a sequence of random data at original sampling rate of 1 Hz at an output sampling of 50 Hz. | |
| 24 </p> | |
| 25 <div class="fragment"><pre> | |
| 26 <br> | |
| 27 <span class="comment">% create an AO of random data with fs = 10 Hz</span> | |
| 28 pl = plist(<span class="string">'tsfcn'</span>, <span class="string">'randn(size(t))'</span>,<span class="string">'fs'</span>,1,<span class="string">'nsecs'</span>,10,<span class="string">'yunits'</span>,<span class="string">'m'</span>,<span class="string">'nsecs'</span>,100); | |
| 29 x = ao(pl); | |
| 30 y = resample(x, plist(<span class="string">'fsout'</span>, 50)); <span class="comment">% resample the input AO (x) to obtain the resampled output AO (y)</span> | |
| 31 iplot(x, y) <span class="comment">% plot original and resampled data</span> | |
| 32 </pre> | |
| 33 </div> | |
| 34 <br> | |
| 35 <br> | |
| 36 <img src="images/resample1.png" alt="Resample"> | |
| 37 <br> | |
| 38 <br> | |
| 39 <br> | |
| 40 <p> | |
| 41 1. Resampling a sequence of random data at original sampling rate of 10 Hz at an output sampling of 1 Hz with | |
| 42 a filter defined by the user. | |
| 43 </p> | |
| 44 <div class="fragment"><pre> | |
| 45 <br> | |
| 46 <span class="comment">% create an AO of random data with fs = 10 Hz</span> | |
| 47 pl = plist(<span class="string">'tsfcn'</span>, <span class="string">'randn(size(t))'</span>,<span class="string">'fs'</span>,10,<span class="string">'nsecs'</span>,10,<span class="string">'yunits'</span>,<span class="string">'m'</span>); | |
| 48 x = ao(pl) | |
| 49 | |
| 50 <span class="comment">% filter definition</span> | |
| 51 plfilter = plist(<span class="string">'type'</span>,<span class="string">'lowpass'</span>,<span class="string">'Win'</span>,specwin(<span class="string">'Kaiser'</span>, 10, 150),<span class="string">'order'</span>,32,<span class="string">'fs'</span>,10,<span class="string">'fc'</span>,1); | |
| 52 f = mfir(plfilter) | |
| 53 | |
| 54 <span class="comment">% resampling</span> | |
| 55 pl = plist(<span class="string">'fsout'</span>, 1, <span class="string">'filter'</span>,f); <span class="comment">% define parameters list with fsout = 1 Hz and the defined filter</span> | |
| 56 y = resample(x, pl); <span class="comment">% resample the input AO (x) to obtain the resampled output AO (y)</span> | |
| 57 iplot(x, y) <span class="comment">% plot original and resampled data</span> | |
| 58 </pre> | |
| 59 </div> | |
| 60 <br> | |
| 61 <br> | |
| 62 <img src="images/resample2.png" alt="Resample" border="0"> | |
| 63 | |
| 64 |