``````            A               B
-----------------------------
1 | Number of responses | Value
2 |         1               1
3 |         3               2
4 |         0               3
``````

Based on this data, I'd like to calculate the median response. The median in this case is obviously 2, since the responses are (1, 2, 2, 2). But how to do this calculation in Google Spreadsheets, preferably in an elegant way?

The best I've come up with is to write a custom function (Tools -> Script Editor):

``````/**
* Returns an array with the specified number of instances with the given
* instanceValue.
*/
function multipleInstances(numberOfInstances, instanceValue) {
if (numberOfInstances == 0) {
return;
}

var instances = [];

for(var i = 0; i < numberOfInstances; i++) {
instances.push(instanceValue);
}

return instances;
}
``````

Then I've invoked the function to calculate the median:

``````=MEDIAN(multipleInstances(A2, B2), multipleInstances(A3, B3), multipleInstances(A4, B4))
``````

This works, but is a bit cumbersome. Is there a more elegant way of saying "give me N instances of the value in this cell"?

The following little script will calculate the median at the same time.

## Code

``````function myMedian(instances, values) {
var ins = [], half;
for(var i = 0, iLen = instances.length; i < iLen; i++) {
for(var k = 0, kLen = instances[i]; k < kLen; k++) {
ins.push(Number(values[i]));
}
}

// reference: https://gist.github.com/caseyjustus/1166258
half = Math.floor(ins.sort( function(a,b) {return a - b;} ).length / 2);

return ins.length % 2 ? ins[half] : (ins[half - 1] + ins[half]) / 2;
}
``````

## Screenshot ## Example

See example file I prepared: Median calculation