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POFirst element in tree becoming null? Guava TreebasedTable
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  1. POFirst element in tree becoming null? Guava TreebasedTable
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    copied!<p>So I am having a problem with a Guava TreeBasedTable (if you're unfamiliar, it's a tree that accesses its elements based on a pair of keys) which over the past week has been a bear to figure out. I'll do my best to explain, removing superfluous code:</p> <pre><code>TreeBasedTable&lt;RowValue, Data, Result&gt; results = TreeBasedTable.create(); for (Data d : data.getData()) { for (Operation o: data.getOperations()) { Result r = o.calculate(...); results.put(r.rowValue, d, r); } } </code></pre> <p>Basically, I iterate over some data that I have, do some calculations, and stick the results in the table. What's strange though, is when I try to access the elements. If I simply iterate over them as follows:</p> <pre><code>for(Result r : results.values()){ System.out.println(r); } </code></pre> <p>everything works normally. However, if I instead try to access them as follows:</p> <pre><code>for(RowValue row : results.rowKeySet()){ for(Data d : results.columnKeySet()){ System.out.println(results.get(row, d)); } } </code></pre> <p>The first element is null somehow. If however the tree is of size 1, it works fine. Could it be there is something about Trees going on here that I am not understanding? Sorry for the long question, I hope it was clear.</p> <p>::EDIT:: The first value passed into the tree is always non-null. When the tree reaches size 3 however, it turns from non-null, to null. Sorry if it wasn't exactly clear what my problem was. As requested, here is the actual code with the actual keys:</p> <p>public void createResults(Options options, MeasuredData data, ArrayList methods) {</p> <pre><code>private TreeBasedTable&lt;MethodDescriptor, Compound, Result&gt; results = TreeBasedTable.create(); for (Compound c : data.getCompounds()) { for (Method method : methods) { ArrayList&lt;Result&gt; calcResults = method.calculate(c, options); for (Result r : calcResults) { results.put(r.getMethod(), c, r); } } } </code></pre> <p>So I run a number of computations on a number of compounds, each of which can produce multiple results. Is there any way I can clarify this?</p>
 

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