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POArea of the nearest boxes
 

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    <p>This question is similar to my previously asked <a href="https://stackoverflow.com/questions/17328004/count-the-number-of-adjacent-boxes">this question</a> . But instead of returning only the number of nearest boxes, I would like to find the area of corresponding boxes.</p> <p><strong>Details:</strong> Suppose I have a set of coordinates of boxes like this-</p> <pre><code>#Rect x1 y1 x2 y2 area 1 0.0000 0.0000 0.8147 0.1355 0.1104 2 0.8147 0.0000 1.0000 0.1355 0.0251 3 0.8147 0.1355 0.9058 0.8350 0.0637 4 0.0000 0.1355 0.1270 0.9689 0.1058 5 0.9058 0.1355 0.9134 0.2210 0.0006 6 0.9058 0.8350 1.0000 1.0000 0.0155 7 0.8147 0.8350 0.9058 1.0000 0.0150 8 0.1270 0.1355 0.6324 0.3082 0.0873 9 0.1270 0.9689 0.8147 1.0000 0.0214 10 0.0000 0.9689 0.1270 1.0000 0.0040 11 0.9134 0.1355 1.0000 0.2210 0.0074 12 0.9134 0.2210 1.0000 0.8350 0.0532 13 0.9058 0.2210 0.9134 0.8350 0.0047 14 0.6324 0.1355 0.8147 0.3082 0.0315 15 0.6324 0.3082 0.8147 0.9689 0.1205 16 0.1270 0.3082 0.6324 0.9689 0.3339 </code></pre> <p>Suppose these coordinates split an unit square into sub-rectangles like this picture- <img src="https://i.stack.imgur.com/gLQ5E.jpg" alt="enter image description here"></p> <p>Now this code returns the value of the number of nearest boxes, but it fails to returns the area of that boxes. Here is my code-</p> <pre><code>#include &lt;iostream&gt; #include &lt;cstdlib&gt; #include &lt;vector&gt; #include &lt;stdio.h&gt; using namespace std; class Rect { public: double x1, x2, y1, y2, area; Rect(double X1, double Y1, double X2, double Y2, double Area) { if (X1 &lt; X2) { x1 = X1; x2 = X2; } else { x2 = X1; x1 = X2; } if (Y1 &lt; Y2) { y1 = Y1; y2 = Y2; } else { y2 = Y1; y1 = Y2; } Area =area; } bool NearestBox(Rect rect) { //for x-axis if (x1 == rect.x2 || x2 == rect.x1) { if (y1 &gt;= rect.y1 &amp;&amp; y1 &lt; rect.y2) { return true; } if (y2 &gt; rect.y1 &amp;&amp; y2 &lt;= rect.y2) { return true; } } // for y-axis if (y1 == rect.y2 || y2 == rect.y1) { if (x1 &gt;= rect.x1 &amp;&amp; x1 &lt; rect.x2) { return true; } if (x2 &gt; rect.x1 &amp;&amp; x2 &lt;= rect.x2) { return true; } } return false; } }; int main() { vector&lt;Rect&gt; rects; //Rect( x1 , y1 , x2 , y2 , area) rects.push_back(Rect(0.0000,0.0000, 0.8147,0.1355, 0.1104)); rects.push_back(Rect(0.8147,0.0000, 1.0000,0.1355, 0.0251)); rects.push_back(Rect(0.8147,0.1355, 0.9058,0.8350, 0.0637)); rects.push_back(Rect(0.0000,0.1355, 0.1270,0.9689, 0.1058 )); rects.push_back(Rect(0.9058,0.1355, 0.9134,0.2210, 0.0006)); rects.push_back(Rect(0.9058,0.8350, 1.0000,1.0000, 0.0155)); rects.push_back(Rect(0.8147,0.8350, 0.9058,1.0000, 0.0150)); rects.push_back(Rect(0.1270,0.1355, 0.6324,0.3082, 0.0873)); rects.push_back(Rect(0.1270,0.9689, 0.8147,1.0000, 0.0214)); rects.push_back(Rect(0.0000,0.9689, 0.1270,1.0000, 0.0040)); rects.push_back(Rect(0.9134,0.1355, 1.0000,0.2210, 0.0074)); rects.push_back(Rect(0.9134,0.2210, 1.0000,0.8350, 0.0532)); rects.push_back(Rect(0.9058,0.2210, 0.9134,0.8350, 0.0047)); rects.push_back(Rect(0.6324,0.1355, 0.8147,0.3082, 0.0315)); rects.push_back(Rect(0.6324,0.3082, 0.8147,0.9689, 0.1205)); rects.push_back(Rect(0.1270,0.3082, 0.6324,0.9689, 0.3339)); int b=13; int nearBox_count = 0; //double area=0; double TotalArea=0; for (int x = 0; x &lt; rects.size(); ++x) { if (rects[b].NearestBox(rects[x])) { if (x==b) { continue; //this is our box , so do not count it. } nearBox_count++; printf("box[%d] is nearest to box[%d] and has area %f \n", (b+1), (x+1), rects[x].area); TotalArea +=rects[x].area; } } printf("Total number of nearest box for box[%d] = %d, and the sum of area is= %f \n", (b+1), nearBox_count, TotalArea ); return 0; } </code></pre> <p>It prints the results-</p> <pre><code>box[14] is nearest to box[1] and has area 0.000000 box[14] is nearest to box[3] and has area 0.000000 box[14] is nearest to box[8] and has area 0.000000 box[14] is nearest to box[15] and has area 0.000000 Total number of nearest box for box[14] = 4, and the sum of area is= 0.000000 </code></pre> <p>So by comparing the results with the picture above, you can see that it returns the value of the nearest boxes but fails to return the value of their corresponding areas.</p> <p>Can anyone help me to fix that?</p>
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    1. COThe reason the areas aren't displaying is because you don't assign them. The only assignment I see is `double area=0;`.
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    2. COYou create a double variable called `area`, you initialize it to zero, you never, ever use it again until a line comes in which you print it out. What do you expect to see?
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      1. USDaniel Daranas
    3. CO@Geobits: Thanks for the reply! How can I fetch the values of area from *Rect* ??
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