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POSearch algorithm for the smallest index in a sequence of vectors matching predefined conditions
 

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  1. POSearch algorithm for the smallest index in a sequence of vectors matching predefined conditions
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    <p>Let us presume we have <strong>k</strong> sequences of fixed length <strong>p</strong>. Each sequence has double values in range <strong>0</strong> to <strong>1.0</strong>. For simplicity let us also assume that the sequences are just arrays; in the real implementation, they will be list.</p> <p>Now, the algorithm needs to find the smallest index the value of which represents a "major upset" in a given sequence. This upset can be a value of <strong>1.0</strong> or a value that goes over a certain threshold (e.g. <strong>0.2</strong>). If, for example, moving from <strong>j-1</strong> to <strong>j</strong> the value increases over the threshold, then the index we seek would be <strong>j-1</strong>.</p> <p>The upset of 1.0 takes precedence over the threshold value; for instance, if we find an index matching the threshold, we should still check the sequence for containing <strong>1.0</strong>.</p> <p>Finally, the algorithm should produce the smallest index that resulted in the upset. I have quickly put together some code to test the concept and show you the sort of thing I am after. What I am looking for is a possibly more efficient implementation as this algorithm is going to be executed pretty extensively.</p> <pre><code>List&lt;double[]&gt; nearCaptures = new ArrayList&lt;double[]&gt;(); double threshold = 0.2; double majorUpset = 1.0; int[] indexes = new int[nearCaptures.size()]; for (int i = 0; i &lt; nearCaptures.size(); i++) { int index = 0; double[] tempArray = nearCaptures.get(i); Arrays.sort(tempArray); int tempIndex = Arrays.binarySearch(tempArray, majorUpset); if (tempIndex &gt; 0) { for (int j = 1; j &lt; nearCaptures.get(0).length; j++) { if (nearCaptures.get(i)[j] == majorUpset) { index = j-1; break; } } } else { for (int j = 1; j &lt; nearCaptures.get(0).length; j++) { if (nearCaptures.get(i)[j] &gt;= nearCaptures.get(i)[j-1] + threshold) { index = j-1; break; } } } indexes[i] = index; } Arrays.sort(indexes); System.out.println(indexes[0]); </code></pre>
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    1. USSvante
    1. USPiotr Murach
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    1. COI think that you actually might mean that an upset is constituted by an increase of a certain magnitude, not an increase over a threshold. I dared not change this, though, as it changes the meaning of what you wrote.
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      1. POSearch algorithm for the smallest index in a sequence of vectors matching predefined conditions
      1. USSvante
    2. COThere is a deeper meaning behind this threshold value which expresses a substantial increase in value, actually fitness value for a given chromosome. I am not sure whether this would be a magnitude of some value but rather constant indicating that very undesirable thing has happened.
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      1. POSearch algorithm for the smallest index in a sequence of vectors matching predefined conditions
      1. USPiotr Murach
 

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