I am trying to use two VLookUps in a row in my macro. The macro counts the IDs in column A and C, searches for the ID description in another table (same sheet and ranges from column F to M -> F = IDs, H = ID description) and continues this search until the count is reached and inserts them in column B and D.
Unfortunately, I get a
run time error 1004
when using the second VLookUp. First one works fine and it's exactly the same as in the first one I am just referring to different cells.
Picture reference of what I am trying to achieve:
Does anyone know what causes this problem?
Dim i As Integer
Dim shA As Worksheet
Set shA = Worksheets(Format(Date, "dd.mm.yyyy"))
With shA
For i = 4 To .Range("A4", .Range("A4").End(xlDown)).Rows.Count + 3
.Cells(i, 2) = .Application.WorksheetFunction.VLookup(.Cells(i, 1), .Range("F:M"), 3, False)
Next i
For i = 4 To .Range("C4", .Range("C4").End(xlDown)).Rows.Count + 3
.Cells(i, 4) = .Application.WorksheetFunction.VLookup(.Cells(i, 3), .Range("F:M"), 3, False)
Next i
End With
Try to replace Integer with Long and try again.
In VBA Integer is
from -2^15 to 2^15-1 or
from -32768 to 32767
Thus, if you use it in Excel and it refers numbers which are outside this range, you get an error. In general, you have some other errors as well. Try this and make sure that you have the correct ActiveSheet selected (I have done it for easy, you may change it later):
Public Sub TestMe()
Dim i As Long
Dim shA As Worksheet
Set shA = ActiveSheet
With shA
For i = 4 To .Range("A4", .Range("A4").End(xlDown)).Rows.Count + 3
.Cells(i, 2) = Application.VLookup(.Cells(i, 1), .Range("F:M"), 3, False)
Next i
For i = 4 To .Range("C4", .Range("C4").End(xlDown)).Rows.Count + 3
.Cells(i, 4) = Application.VLookup(.Cells(i, 3), .Range("F:M"), 3, False)
Next i
End With
End Sub
Thus, in general:
Do not use On Error Resume Next, because it is a bit tough.
When you use With Worksheets("someName"), then make sure that every time you put a dot ., the child is a real child of the with-Parent. In your case .Application is not a child of Worksheets()
Do not use Integer, but Long
I am having trouble figuring out how to subtract two ranges from each other, some cells in range H:H have "#N/A" while in range D:D there are no errors. I know in Excel it's a simple "=H2-D2" and drag that down but I'm in the process of recording a Macro and wanted to automate the subtraction as well. So far this is what I have:
Dim quantity1, quantity2, rIntersect, Qdiff, x As Range
Set quantity1 = Range("D:D")
Set quantity2 = Range("H:H")
Set rIntersect = Intersect(quantity1, quantity2)
For Each x In quantity1
If Intersect(rIntersect, x) Is Nothing Then
If Qdiff Is Nothing Then
Set Qdiff = x
Else
Set Qdiff = Application.Union(Qdiff, x)
End If
End If
Next x
Range("J2").Select
Dim lastRowJ As Long
lastRowJ = Range("A" & Rows.Count).End(xlUp).Row
Range("J2").AutoFill Destination:=Range("J2:J" & lastRowJ)
Place this procedure in a standard code module:
Public Sub Subtract()
[j2:j99] = [h2:h99-d2:d99]
End Sub
If you like how that works, I'm happy to embellish it so that it is not hard-coded for 98 rows only. Let me know.
UPDATE
Here is a version that will deal with any number of rows. It keys off of column D. So if there are 567 numbers in column D, then you will get 567 corresponding (subtracted) results in column J.
This assumes that the data start in row 2, and that there are no blank cells until the numbers in column D end.
If you are going to call this from the Macro Dialog then you should keep it Public. If on the other hand you are going to call it from another procedure in the same module, then you can make it Private.
Here is the enhanced solution:
Public Sub Subtract()
Dim k&
Const F = "iferror(h2:h[]-d2:d[],0)"
k = [count(d:d)]
[j2].Resize(k) = Evaluate(Replace(F, "[]", k + 1))
End Sub
Note that the routine now handles the errors and places a ZERO value in column J when the corresponding value in column H is an error. If you would prefer to have something other than a ZERO (like a blank for instance) when there are errors in column H, just let me know and I'll update to whatever you want.
UPDATE 2
Here is how to handle displaying blanks instead of zeroes:
Public Sub Subtract()
Dim k&
Const F = "iferror(if(h2:h[]-d2:d[]=0,"""",h2:h[]-d2:d[]),0)"
k = [count(d:d)]
[k2].Resize(k) = Evaluate(Replace(F, "[]", k + 1))
End Sub
I'm trying to delete rows on one worksheet based on a range in another worksheet. I think the problem here is probably something simple based on my limited VBA experience. Here is the code I've written:
Sub LimitedElements()
imax = ActiveSheet.Cells.SpecialCells(xlCellTypeLastCell).Row
For i = 2 To imax
If Sheets("test").Cells(j, 1).Value = Sheets("Limited Elements").Range("A1:A10") Then
Rows(i).EntireRow.Delete
End If
Next i
End Sub
I get a message saying "Application-defined or object-defined error".
Can anyone tell me what I'm doing wrong? Or if this is just a dumb way to do this and I should be doing it differently?
Please see if below works for you:
Sub LimitedElements()
Dim imax As Integer
Dim a As Variant
Dim b As Range
Dim c As Object
Dim d As Integer
imax = ActiveSheet.Cells.SpecialCells(xlCellTypeLastCell).Row
For i = 2 To imax
a = Sheets("test").Cells(i, 1).Value
Set b = Sheets("Limited Elements").Range("A1:A10")
Set c = b.Find(What:=a, LookIn:=xlValues)
If Not c Is Nothing Then
Sheets("test").Rows(i).EntireRow.Delete
i = i - 1
imax = imax - 1
End If
Next i
End Sub
Noted that it is not fine tuned and is intended to give you an understanding on how to approach the solution.
I added code to decrement i. I think I understand that the code can't tell which worksheet I'm specifying for deleting the row but I'm not sure what to do about it. I tried changing "Rows(i).EntireRow.Delete" to "Sheets("test").Rows(i).EntireRow.Delete" but I'm not sure if that's the right thing to do or not.
Some extra details to make things clearer:
Sheet "test" has about 1000 rows with unique numbers in column A. Sheet "Limited Elements" has about 100 rows with unique numbers column A. I want it it delete the rows in "test" that have values in column A that match the column A values in "Limited Elements".
Sub LimitedElements()
imax = ActiveSheet.Cells.SpecialCells(xlCellTypeLastCell).Row
For i = 2 To imax
If Sheets("test").Cells(i, 1).Value = Sheets("Limited Elements").Range("A1:A10") Then
Sheets("test").Rows(i).EntireRow.Delete
i = i - 1
imax = imax - 1
End If
Next i
End Sub
I think the original problem was that I had Cells(j,1) instead of cells(i,1). Now I've fixed that but it gives me a type mismatch error which I think is due to comparing a single cell to a range.
At this point I think I'm just lost. I can't figure out how to change it so it works and does what I want it to do.
I'm trying to write a function which returns the value of a specific cell located on the same column as the one I give in argument, (lig= row number, col=column number), but everytime I run it, I get an error '1004", here's my code:
Function week(lig As Integer, col As Integer) As Integer
Dim i As Integer
i = 0
Do Until Cells(lig - i, 1) = "Row labels"
i = i + 1
Loop
week = Cells(lig - i, col)
End Function
The line in which the error appears is :
Do Until Cells(lig - i, 1) = "Row labels"
I know that I test the values of cells containing integers before getting to this one, I suspeect a type error, but I can't fix it.
Could anyone please help ?
The error isn't a type error. The problem is that you are trying to access a cell that doesn't exist. Your loop evidently fails to reach a cell that holds the value "Row labels" and eventually tries to access Cells(0,1) -- which triggers error 1004. As to why this is happening -- you haven't provided enough details to say.
I suspect that the value in the cell is actually "Row Labels" or "ROW LABELS" or Row labels " or something else that doesn't actually match exactly. Try this:
Do Until Trim(Ucase(Cells(lig - i, 1))) = "ROW LABELS"
Or if you simply want to stop at row one use this:
Do Until lig - i = 1
i=0 will cause an error as the cells(0,1) does not exist in the sheet. You may also want an exit clause for if your logic is never found as you will get an error when you hit the end of the sheet. if you pass this lig =1 you will also get an error (as lig - i (1-1) would result in 0)so you may also want to handle that scenario
Function week(lig As Integer, col As Integer) As Integer
Dim i As Integer
i = 1'Changed to 1
Do Until Cells(lig - i, 1) = "Row labels"
i = i + 1
if i > 1000000 then exit do 'Exit clause
Loop
if i < 1000000 then
week = Cells(lig - i, col)
else
week = 0'Handle 0's in calling code
end if
End Function
You might like to consider re-writing as follows, which I think is clearer.
Function week(lig As Integer, col As Integer) As Integer
Dim i As Integer
' Thsi function will return 0 if no row with the text is found
week = 0
For i = lig To 1 Step -1
If Cells(i, 1) = "Row labels" Then
week = Cells(i, col)
Exit For
End If
Next i
End Function
' EVEN BETTER USE THIS (or similar)!
Function week(MyCell As Range) As Integer
Dim i As Integer
week = 0
For i = MyCell.Row To 1 Step -1
If MyCell.Parent.Cells(i, 1) = "Row labels" Then
week = MyCell.Parent.Cells(i, MyCell.Column)
Exit For
End If
' Note
' MyCell.Parent. returns the sheet containing the cell
' Just using Cells(i, 1) (wihtout preceeding with "MyCell.Parent." will pick up
' cells on the currently active sheet, which may not be the sheet with the cell!
'
Next i
End Function
I have a two dimensional table with countries and years in Excel. eg.
1961 1962 1963 1964
USA a x g y
France u e h a
Germany o x n p
I'd like to "flatten" it, such that I have Country in the first col, Year in the second col, and then value in the third col. eg.
Country Year Value
USA 1961 a
USA 1962 x
USA 1963 g
USA 1964 y
France 1961 u
...
The example I present here is only a 3x4 matrix, but the real dataset i have is significantly larger (roughly 50x40 or so).
Any suggestions how I can do this using Excel?
You can use the excel pivot table feature to reverse a pivot table (which is essentially what you have here):
Good instructions here:
http://spreadsheetpage.com/index.php/tip/creating_a_database_table_from_a_summary_table/
Which links to the following VBA code (put it in a module) if you don't want to follow the instructions by hand:
Sub ReversePivotTable()
' Before running this, make sure you have a summary table with column headers.
' The output table will have three columns.
Dim SummaryTable As Range, OutputRange As Range
Dim OutRow As Long
Dim r As Long, c As Long
On Error Resume Next
Set SummaryTable = ActiveCell.CurrentRegion
If SummaryTable.Count = 1 Or SummaryTable.Rows.Count < 3 Then
MsgBox "Select a cell within the summary table.", vbCritical
Exit Sub
End If
SummaryTable.Select
Set OutputRange = Application.InputBox(prompt:="Select a cell for the 3-column output", Type:=8)
' Convert the range
OutRow = 2
Application.ScreenUpdating = False
OutputRange.Range("A1:C3") = Array("Column1", "Column2", "Column3")
For r = 2 To SummaryTable.Rows.Count
For c = 2 To SummaryTable.Columns.Count
OutputRange.Cells(OutRow, 1) = SummaryTable.Cells(r, 1)
OutputRange.Cells(OutRow, 2) = SummaryTable.Cells(1, c)
OutputRange.Cells(OutRow, 3) = SummaryTable.Cells(r, c)
OutputRange.Cells(OutRow, 3).NumberFormat = SummaryTable.Cells(r, c).NumberFormat
OutRow = OutRow + 1
Next c
Next r
End Sub
-Adam
In Excel 2013 need to follow next steps:
select data and convert to table (Insert -> Table)
call Query Editor for table (Power Query -> From Table)
select columns that contain years
in context menu select 'Unpivot Columns'-command.
Support Office: Unpivot columns (Power Query)
In Excel 2016, Power Query is called Get & Transform and it is found in the Data tab.
#Adam Davis's answer is perfect, but just in case you're as clueless as I am about Excel VBA, here's what I did to get the code working in Excel 2007:
Open the workbook with the Matrix that needs to be flattened to a table and navigate to that worksheet
Press Alt-F11 to open the VBA code editor.
On the left pane, in the Project box, you'll see a tree structure representing the excel objects and any code (called modules) that already exist. Right click anywhere in the box and select "Insert->Module" to create a blank module file.
Copy and paste #Adman Davis's code from above as is into the blank page the opens and save it.
Close the VBA editor window and return to the spreadsheet.
Click on any cell in the matrix to indicate the matrix you'll be working with.
Now you need to run the macro. Where this option is will vary based on your version of Excel. As I'm using 2007, I can tell you that it keeps its macros in the "View" ribbon as the farthest right control. Click it and you'll see a laundry list of macros, just double click on the one called "ReversePivotTable" to run it.
It will then show a popup asking you to tell it where to create the flattened table. Just point it to any empty space an your spreadsheet and click "ok"
You're done! The first column will be the rows, the second column will be the columns, the third column will be the data.
Flattening a data matrix (aka Table) can be accomplished with one array formula¹ and two standard formulas.
The array formula¹ and two standard formulas in G3:I3 are is,
=IFERROR(INDEX(A$2:A$4, MATCH(0, IF(COUNTIF(G$2:G2, A$2:A$4&"")<COUNT($1:$1), 0, 1), 0)), "")
=IF(LEN(G3), INDEX($B$1:INDEX($1:$1, MATCH(1E+99,$1:$1 )), , COUNTIF(G$3:G3, G3)), "")
=INDEX(A:J,MATCH(G3,A:A,0),MATCH(H3,$1:$1,0))
Fill down as necessary.
While array formulas can negatively impact performance due to their cyclic calculation, your described working environment of 40 rows × 50 columns should not overly impact performance with a calculation lag.
¹ Array formulas need to be finalized with Ctrl+Shift+Enter↵. Once entered into the first cell correctly, they can be filled or copied down or right just like any other formula. Try and reduce full-column references to ranges more closely representing the extents of your actual data. Array formulas chew up calculation cycles logarithmically so it is good practise to narrow the referenced ranges to a minimum. See Guidelines and examples of array formulas for more information.
For anyone who wants to use the PivotTable to do this and is following the below guide:
http://spreadsheetpage.com/index.php/tip/creating_a_database_table_from_a_summary_table/
If you want to do it in Excel 2007 or 2010 then you first need to enable the PivotTable Wizard.
To find the option you need to go to "Excel Options" via the Main Excel Window icon, and see the options selected in the "customize" section, then select "Commands Not in the Ribbon" from the "Choose Commands from:" dropdown and "PivotTable and PivotChart Wizard" needs to be added to the right.. see the image below.
Once that is done there should be a small pivottable wizard icon in the quickbar menu at the top of the Excel window, you can then follow the same process as shown in the link above.
I developed another macro because I needed to refresh the output table quite often (input table was filled by other) and I wanted to have more info in my output table (more copied column and some formulas)
Sub TableConvert()
Dim tbl As ListObject
Dim t
Rows As Long
Dim tCols As Long
Dim userCalculateSetting As XlCalculation
Dim wrksht_in As Worksheet
Dim wrksht_out As Worksheet
'##block calculate and screen refresh
Application.ScreenUpdating = False
userCalculateSetting = Application.Calculation
Application.Calculation = xlCalculationManual
'## get the input and output worksheet
Set wrksht_in = ActiveWorkbook.Worksheets("ressource_entry")'## input
Set wrksht_out = ActiveWorkbook.Worksheets("data")'## output.
'## get the table object from the worksheet
Set tbl = wrksht_in.ListObjects("Table14") '## input
Set tb2 = wrksht_out.ListObjects("Table2") '## output.
'## delete output table data
If Not tb2.DataBodyRange Is Nothing Then
tb2.DataBodyRange.Delete
End If
'## count the row and col of input table
With tbl.DataBodyRange
tRows = .Rows.Count
tCols = .Columns.Count
End With
'## check every case of the input table (only the data part)
For j = 2 To tRows '## parse all row from row 2 (header are not checked)
For i = 5 To tCols '## parse all column from col 5 (first col will be copied in each record)
If IsEmpty(tbl.Range.Cells(j, i).Value) = False Then
'## if there is time enetered create a new row in table2 by using the first colmn of the selected cell row and cell header plus some formula
Set oNewRow = tb2.ListRows.Add(AlwaysInsert:=True)
oNewRow.Range.Cells(1, 1).Value = tbl.Range.Cells(j, 1).Value
oNewRow.Range.Cells(1, 2).Value = tbl.Range.Cells(j, 2).Value
oNewRow.Range.Cells(1, 3).Value = tbl.Range.Cells(j, 3).Value
oNewRow.Range.Cells(1, 4).Value = tbl.Range.Cells(1, i).Value
oNewRow.Range.Cells(1, 5).Value = tbl.Range.Cells(j, i).Value
oNewRow.Range.Cells(1, 6).Formula = "=WEEKNUM([#Date])"
oNewRow.Range.Cells(1, 7).Formula = "=YEAR([#Date])"
oNewRow.Range.Cells(1, 8).Formula = "=MONTH([#Date])"
End If
Next i
Next j
ThisWorkbook.RefreshAll
'##unblock calculate and screen refresh
Application.ScreenUpdating = True
Application.Calculate
Application.Calculation = userCalculateSetting
End Sub
VBA solution may not be acceptable under some situations (e.g. cannot embed macro due to security reasons, etc.). For these situations, and otherwise too in general, I prefer using formulae over macro.
I am trying to describe my solution below.
input data as shown in question (B2:F5)
column_header (C2:F2)
row_header (B3:B5)
data_matrix (C3:F5)
no_of_data_rows (I2) = COUNTA(row_header) + COUNTBLANK(row_header)
no_of_data_columns (I3) = COUNTA(column_header) + COUNTBLANK(column_header)
no_output_rows (I4) = no_of_data_rows*no_of_data_columns
seed area is K2:M2, which is blank but referenced, hence not to be deleted
K3 (drag through say K100, see comments description) = ROW()-ROW($K$2) <= no_output_rows
L3 (drag through say L100, see comments description) = IF(K3,IF(COUNTIF($L$2:L2,L2)
M3 (drag through say M100, see comments description) = IF(K3,IF(M2 < no_of_data_columns,M2+1,1),"-")
N3 (drag through say N100, see comments description) = INDEX(row_header,L3)
O3 (drag through say O100, see comments description) = INDEX(column_header,M3)
P3 (drag through say P100, see comments description) = INDEX(data_matrix,L3,M3)
Comment in K3: Optional: Check if expected no. of output rows has been achieved. Not required, if one only prepares this table limited to no. of output rows.
Comment in L3: Goal: Each RowIndex (1 .. no_of_data_rows) must repeat no_of_data_columns times. This will provide index lookup for row_header values. In this example, each RowIndex (1 .. 3) must repeat 4 times. Algorithm: Check how many times RowIndex has occurred yet. If it less than no_of_data_columns times, continue using that RowIndex, else increment the RowIndex. Optional: Check if expected no. of output rows has been achieved.
Comment in M3: Goal: Each ColumnIndex (1 .. no_of_data_columns) must repeat in a cycle. This will provide index lookup for column_header values. In this example, each ColumnIndex (1 .. 4) must repeat in a cycle. Algorithm: If ColumnIndex exceeds no_of_data_columns, restart the cycle at 1, else increment the ColumnIndex. Optional: Check if expected no. of output rows has been achieved.
Comment in R4: Optional: Use column K for error handling, as shown in column L and column M. Check if looked up value IsBlank to avoid incorrect "0" in the output because of blank input in data_matrix.
updated ReversePivotTable function so i can specify number of header columns and rows
Sub ReversePivotTable()
' Before running this, make sure you have a summary table with column headers.
' The output table will have three columns.
Dim SummaryTable As Range, OutputRange As Range
Dim OutRow As Long
Dim r As Long, c As Long
Dim lngHeaderColumns As Long, lngHeaderRows As Long, lngHeaderLoop As Long
On Error Resume Next
Set SummaryTable = ActiveCell.CurrentRegion
If SummaryTable.Count = 1 Or SummaryTable.Rows.Count < 3 Then
MsgBox "Select a cell within the summary table.", vbCritical
Exit Sub
End If
SummaryTable.Select
Set OutputRange = Application.InputBox(prompt:="Select a cell for the 3-column output", Type:=8)
lngHeaderColumns = Application.InputBox(prompt:="Header Columns")
lngHeaderRows = Application.InputBox(prompt:="Header Rows")
' Convert the range
OutRow = 2
Application.ScreenUpdating = False
'OutputRange.Range("A1:D3") = Array("Column1", "Column2", "Column3", "Column4")
For r = lngHeaderRows + 1 To SummaryTable.Rows.Count
For c = lngHeaderColumns + 1 To SummaryTable.Columns.Count
' loop through all header columns and add to output
For lngHeaderLoop = 1 To lngHeaderColumns
OutputRange.Cells(OutRow, lngHeaderLoop) = SummaryTable.Cells(r, lngHeaderLoop)
Next lngHeaderLoop
' loop through all header rows and add to output
For lngHeaderLoop = 1 To lngHeaderRows
OutputRange.Cells(OutRow, lngHeaderColumns + lngHeaderLoop) = SummaryTable.Cells(lngHeaderLoop, c)
Next lngHeaderLoop
OutputRange.Cells(OutRow, lngHeaderColumns + lngHeaderRows + 1) = SummaryTable.Cells(r, c)
OutputRange.Cells(OutRow, lngHeaderColumns + lngHeaderRows + 1).NumberFormat = SummaryTable.Cells(r, c).NumberFormat
OutRow = OutRow + 1
Next c
Next r
End Sub
Code with the claim for some universality
The book should have two sheets:
Sour = Source data
Dest = the "extended" table will drop here
Option Explicit
Private ws_Sour As Worksheet, ws_Dest As Worksheet
Private arr_2d_Sour() As Variant, arr_2d_Dest() As Variant
' https://stackoverflow.com/questions/52594461/find-next-available-value-in-excel-cell-based-on-criteria
Public Sub PullOut(Optional ByVal msg As Variant)
ws_Dest_Acr _
arr_2d_ws( _
arr_2d_Dest_Fill( _
arr_2d_Sour_Load( _
arr_2d_Dest_Create( _
CountA_rng( _
rng_2d_For_CountA( _
Init))))))
End Sub
Private Function ws_Dest_Acr(Optional ByVal msg As Variant) As Variant
ws_Dest.Activate
End Function
Public Function arr_2d_ws(Optional ByVal msg As Variant) As Variant
If IsArray(arr_2d_Dest) Then _
ws_Dest.Cells(1, 1).Resize(UBound(arr_2d_Dest), UBound(arr_2d_Dest, 2)) = arr_2d_Dest
End Function
Private Function arr_2d_Dest_Fill(Optional ByVal msg As Variant) As Variant
Dim y_Sour As Long, y_Dest As Long, x As Long
y_Dest = 1
For y_Sour = LBound(arr_2d_Sour) To UBound(arr_2d_Sour)
' without the first column
For x = LBound(arr_2d_Sour, 2) + 1 To UBound(arr_2d_Sour, 2)
If arr_2d_Sour(y_Sour, x) <> Empty Then
arr_2d_Dest(y_Dest, 1) = arr_2d_Sour(y_Sour, 1) 'iD
arr_2d_Dest(y_Dest, 2) = arr_2d_Sour(y_Sour, x) 'DTLx
y_Dest = y_Dest + 1
End If
Next
Next
End Function
Private Function arr_2d_Sour_Load(Optional ByVal msg As Variant) As Variant
arr_2d_Sour = ReDuce_rng(ws_Sour.UsedRange, 1, 0).Offset(1, 0).Value
End Function
Private Function arr_2d_Dest_Create(ByVal iRows As Long)
Dim arr_2d() As Variant
ReDim arr_2d(1 To iRows, 1 To 2)
arr_2d_Dest = arr_2d
arr_2d_Dest_Create = arr_2d
End Function
Public Function CountA_rng(ByVal rng As Range) As Double
CountA_rng = Application.WorksheetFunction.CountA(rng)
End Function
Private Function rng_2d_For_CountA(Optional ByVal msg As Variant) As Range
' without the first line and without the left column
Set rng_2d_For_CountA = _
ReDuce_rng(ws_Sour.UsedRange, 1, 1).Offset(1, 1)
End Function
Public Function ReDuce_rng(rng As Range, ByVal iRow As Long, ByVal iCol As Long) _
As Range
With rng
Set ReDuce_rng = .Resize(.Rows.Count - iRow, .Columns.Count - iCol)
End With
End Function
Private Function Init()
With ThisWorkbook
Set ws_Sour = .Worksheets("Sour")
Set ws_Dest = .Worksheets("Dest")
End With
End Function
'https://youtu.be/oTp4aSWPKO0