VBA code to select columns based on user defined variables in cells - vba

Question

I am trying to write a code for my macro in excel with VBA but I keep getting stuck on the user defined variable part. I currently have a spreadsheet with four sets of measured data that correspond to a single date.
What I am trying to achieve is:
-Have one cell for a start date, and another cell for an end date that is specified by the user; I want to macro to read these two cells and use these two dates, read the data between them, and create a line graph corresponding to these dates with the 4 data series I have.
The end goal is to be able to create a chart between whichever two dates the user wishes to.
I have figured out the macro to plot the line graph if I specify the entire column (i.e. I have put B3:F170 as the data range) however I am not sure how integrate a user defined range in the code.
Any help would be greatly appreciated. Many thanks in advance.
Edit: Here's what I have so far, sorry if its quite messy I am just starting out!
Dim chtChart As Chart
Set chtChart = Charts.Add
With chtChart
.Name = "Chart Name"
.ChartType = xlLine
.SetSourceData Source:=Sheets("Sheet1").Range("B3:F170"),_
PlotBy:=xlColumns
End With
Dim FromDateCell As String
Dim ToDateCell As String
Dim DateRange As Range
FromDateCell = Range("I13").Value
ToDateCell = Range("I14").Value
DateRange = Range(FromDateCell, ToDateCell)
Range(DateRange).Select

Answer 1

you could first set the wanted data range and then assign it as your new chart Source, like follows:
Option Explicit
Sub main()
Dim chtChart As Chart
Dim FromDateCell As Range, ToDateCell As Range, DataRange As Range
With Sheets("Sheet1") '<--| reference your relavant sheet
Set FromDateCell = .Range("B3:B170").Find(.Range("I13").Value, LookIn:=xlValues, lookat:=xlWhole) '<--| get "initial date" cell in range B3:B170
Set ToDateCell = .Range("B3:B170").Find(.Range("I14").Value, LookIn:=xlValues, lookat:=xlWhole) '<--| get "final date" cell in range B3:B170
Set DataRange = Range(FromDateCell, ToDateCell).Resize(, 5) '<--| set the "data" range as the one ranging form "initial date" to "final date" cells extended to enclose four columns to the right
End With
Set chtChart = Charts.Add
With chtChart
.Name = "Chart Name"
.ChartType = xlLine
.SetSourceData Source:=DataRange, PlotBy:=xlColumns
End With
End Sub
the same code could be rewritten (i.e. refactored) to use a specific function to get the wanted range and have your main code more readable and the whole code more maintainable
like follows:
Sub main()
Dim chtChart As Chart
Set chtChart = Charts.Add
With chtChart
.Name = "Chart Name"
.ChartType = xlLine
.SetSourceData Source:=GetDataRange, PlotBy:=xlColumns '<--| here you use GetDataRange() function to return the wanted range
End With
End Sub
Function GetDataRange() As Range
Dim FromDateCell As Range, ToDateCell As Range
With Sheets("Sheet 1")
Set FromDateCell = .Range("B3:B170").Find(.Range("I13").Value, LookIn:=xlValues, lookat:=xlWhole)
Set ToDateCell = .Range("B3:B170").Find(.Range("I14").Value, LookIn:=xlValues, lookat:=xlWhole)
Set GetDataRange = .Range(FromDateCell, ToDateCell).Resize(, 5)
End With
End Function

Answer 2

I think you can achieve this quite simply by using named ranges. Define a named range with the formula
=OFFSET(A8:E200,0,<column>)
Enter that as the data series as input range for the graph as
=<sheet1>! <name>
Replace all values between < and > to whatever is applicable to you. See full reference at https://support.microsoft.com/en-us/kb/183446
You can also use the offset formula in combination with index/match to find the starting/end point in order to get a subset of your data.