Hello Monks,
I have been given a large array of numbers, but there are missing values which have a value of NULL. I am to write a program which takes the NULL values and copies the closest value in the array. If a missing value is equidistant between two values, then it will take the average of the two arrays. To illustrate (let underscores represent NULL values:
4 _ _ _ 5
The first NULL would take the value 4, the third NULL takes the value 5, and the middle NULL takes the value 4.5
The code I have written is below, but it doesn't appear to change anything. Any ideas to get me moving? Thanks monks
$left = 1; #measures the distance to the left to the first non-NULL v
+alue
$right = 1; #measures the distance to the right to the first non-NULL
+value
$q = 0; #used to iterate through the exposures for the first time
$p = 0; #used to find a non-NULL value to the left, first iteration
$k = 0; #used to find a non-NULL value to the right, first iteration
$m = 0; #used to iterate through the exposures for the second time
$n = 0; #used to find a non-NULL value to the left, second iteration
$l = 0; #used to find a non-NULL value to the right, second iteration
$o = 0; #used to assign values using an average, third iteration
foreach $exp (@exposures) {
if ($exp eq "NULL") {
while ($exposures[$q - $p] eq "NULL") {
++$left;
++$p;
}
while($exposures[$q + $k] eq "NULL") {
++$right;
++$k;
}
}
if ($left < $right) {
$data{$q} = "L";
}
if ($left > $right) {
$data{$q} = "R";
}
$left = 1;
$right = 1;
$p = 0;
$k = 0;
++$q;
}
$end = $#exposures;
$number_of_exposures = $end + 1;
while ($m <= $number_of_exposures) {
if ($data{$m} eq "L") {
while ($exposures[$m - $n] eq "NULL") {
++$n;
}
$exposures[$m] = $exposures[4];
}
if ($data{$m} eq "R") {
while ($exposures[$m + $l] eq "NULL"){
++$l;
}
$exposures[$m] = $exposures[4];
}
$n = 0;
$l = 0;
++$m;
}
foreach $exp (@exposures) {
if ($exp eq "NULL") {
$exp = ($exposures[$o - 1] + $exposures[$o + 1])/2;
}
++$o;
}
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