I have an array that has been sorted from low to high which has over 260k values in. I have found out the mean(average) and median of the array just need to find out the mode?
I cannot use any mathematical functions that PHP has, it has to be all done manually.
I would like it so there could be just one value that is the mode but then there can be multiple values that can be the mode. I also need to be able to record the number of times that the value is stored. For example the number 51 appears 6 times so I can print both values.
This is my code so far:
$amountRecords = 0;
$totalValue = 0;
$valueArray = array();
// reads in csv file
$handle = fopen('Task1-DataForMeanMedianMode.csv', 'r');
// to skip the header names/values
fgetcsv($handle);
// creates array containing variables of csv file in ascending order
while(($row = fgetcsv($handle, "\r")) != FALSE)
{
// if amountRecords equals 0
if($amountRecords == 0)
{
// adds value from csv to array
$valueArray[] = $row[1];
} // else amountRecords does not equal 0
else
{
// if the value in array location before is greater than the current value from the csv file
if($valueArray[$amountRecords - 1] > $row[1])
{
// the current array location becomes the one in the location before
$valueArray[] = $valueArray[$amountRecords - 1];
// add the value from the csv to the location before
$valueArray[$amountRecords - 1] = $row[1];
} // if the value in the location before is not greater than the current value in the csv file
else
{
// adds value from csv to array
$valueArray[] = $row[1];
}
}
// calculates the total value of the values in csv file
$totalValue = $totalValue + $row[1];
// calculates the number of values in the csv file
$amountRecords++;
}
// calculate average value of payments
$averageValue = $totalValue / $amountRecords;
// limit integer to 2 decimal place
$average = number_format($averageValue,2,'.','');
// finds middle value
$middle = floor(($amountRecords / 2) - 1);
// calculates the median value
// if array size is even
if($amountRecords % 2 == 0)
{
// calculates median
$median = $valueArray[$middle];
}
else // if array size is odd
{
// calculate low and high values
$low = $valueArray[$middle];
$high = $valueArray[$middle + 1];
// calculates median
$median = (($low + $high) / 2);
}
// works out mode
// creates array count
$count = array();
// for each value in the valueArray
foreach( $valueArray as $value )
{
if( isset( $count[$value] ))
{
$count[$value]++;
}
else
{
$count[$value] = 1;
}
}
$mostCommon = "";
$iter = 0;
foreach( $count as $k => $v )
{
if( $v > $iter )
{
$mostCommon = $k;
$iter = $v;
}
}
$modeArray = array( "mode" => $mostCommon , "count" => $iter );
The mode of a numerical set is the number that occurs the most often. You can do this with PHP using code similar to the following:
$values = array_count_values($valueArray);
$mode = array_search(max($values), $values);
Simple!
$arr = array(4,6,7,1,4,7,4,7,1);
$freq = array();
for($i=0; $i<count($arr); $i++)
{
if(isset($freq[$arr[$i]])==false)
{
$freq[$arr[$i]] = 1;
}
else
{
$freq[$arr[$i]]++;
}
}
$maxs = array_keys($freq, max($freq));
for($i=0; $i<count($maxs); $i++)
{
echo $maxs[$i] . ' ' . $freq[$maxs[$i]];
echo '<br />';
}
来源：https://stackoverflow.com/questions/12036114/how-to-find-the-mode-of-an-array-in-php