How to reshape data for wide to long form by monthly columns name GoogleSheet

Question

In R , data.table library dcast() can transform dataset from wide to long shape ,how can i do this in googlespreadsheet?

From this format :

          | JAN        | FEB        | MAR 
----------+------------+------------+-----------
Product 1 |          1 |          2 |          3
Product 2 |          4 |          5 |          6
Product 3 |          7 |          8 |          9

Convert it to this format:

Date|  Product  | Qty
-----------+-----------+----
JAN | Product 1 |   1
FEB | Product 2 |   4
MAR | Product 3 |   9
JAN | Product 2 |   4
FEB | Product 1 |   2
JAN | Product 3 |   7
MAR | Product 2 |   6
FEB | Product 3 |   8
MAR | Product 1 |   3

Do we have any solution to achieve this ?

Answer 1

How about this sample script?

Sample script:

When you use this script, at first, please put the input values to the cells "A1:D4", and run myFunction().

function myFunction() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var values = sheet.getRange("A1:D4").getValues(); // Retrieve values

  var result = [];
  for (var i = 1; i < values.length; i++) {
    for (var j = 1; j < values[i].length; j++) {
      result.push([values[0][i], values[j][0], values[j][i]]);
    }
  }

  sheet.getRange("A6:C14").setValues(result); // Put result
}

• In this sample script, it supposes the following situation.
  • Input values are put to the cells "A1:D4" of the active sheet.
  • Output values are put to the cells "A6:C14" of the active sheet.

Result:

Other pattern:

When result.push([values[0][i], values[j][0], values[j][i]]); is modified to temp.push([values[0][j], values[i][0], values[i][j]]);, the following result is obtained.

Note:

• In these sample scripts, this script was modified.