title: Use of INDEX MATCH to find absolute closest value
body: <p>I've long sought a method for using <code>INDEX MATCH</code> in Excel to return the absolute closest number in an array without reorganizing my data (since <code>MATCH</code> requires <code>lookup_array</code> to be in descending order to find the closest value greater than <code>lookup_value</code>, but ascending order to find the closest value less than <code>lookup_value</code>).</p>
  <p>I found the answer in <a href="https://stackoverflow.com/questions/23757793/use-index-match-to-find-greater-than-equal-to-value">this post</a>. XOR LX's solution:</p>
  <pre><code>=INDEX(B4:B10,MATCH(TRUE,INDEX(ABS(A4:A10-B1)=MIN(INDEX(ABS(A4:A10-B1),,)),,),0))
  </code></pre>
  <p>worked perfectly for me, but I don't know why. I can rationalize most of it but I can't figure out this part</p>
  <p><code>INDEX(ABS(A4:A10-B1)=MIN(INDEX(ABS(A4:A10-B1),,))</code></p>
  <p>Can anyone please explain this part?</p>