Automate a Solver solution

[Janet]

I need to calculate a value to minimize a formula - I can do this with
Solver. The problem: I have 400 rows for which I have to use the Solver
calculation - and I need to update it occasionally.
I'm trying to figure out how to do this automatically instead of solving
each line manually. I suppose I could write a macro, but I don't know how to
make the macro repeat itself until the last row and then stop. Any ideas?
Thanks.

 

[L. Howard Kittle]

Maybe something like this will get you started, where the value you want to
insert in the cells is in F1 and the 400 cells are D1400


Sub ForHunRow()
Dim i As Integer
Dim j As Range, c As Range

i = Range("F1").Value
Set j = Range("D1400")

For Each c In j
c.Value = i
Next

End Sub

HTH
Regards,
Howard

 

[Janet]

Well, I assumed I could write a macro for a Solver transaction, but I keep
getting for "SolverOK" in the macro: Compile Error; Sub or Function not
defined. That probably means that a macro will not run the Solver for me,
right?

 

[Tom Hutchins]

Before you can use Solver functions in VBA, you must establish a reference to
the Solver add-in. In the Visual Basic Editor, with a module active, click
References on the Tools menu, and then select the Solver.xlam check box under
Available References. If Solver.xlam does not appear under Available
References, click Browse and open Solver.xlam in the \office12\library\Solver
subfolder. If you have already installed the Solver add-in in Excel, you will
probably see it listed under Available References.

To install Solver in Excel 2007:
If the Solver button does not appear on the Data tab on the Ribbon, click
the Microsoft Office Button, Excel Options, Add-Ins category, and then click
the Go button. Then select the Solver Add-In check box, and click OK to
install it. Click Yes to confirm that you want to install the Solver add-in.

For Excel 2003, I think you need SOLVER.XLA. Sorry, but I only have XL2007
available at the moment. The steps should be similar.

Hope this helps,

Hutch

 

[Janet]

Thanks!!! That did the trick, but now I don't know how to integrate the
macro I just wrote into the program that Howard gave me so it will repeat
itself for the relevant rows:

Sub ForHunRow()
Dim i As Integer
Dim j As Range, c As Range

i = Range("F1").Value
Set j = Range("D1400")

For Each c In j
c.Value = i
Next

End Sub

 

[Tom Hutchins]

The For...Next loop he gave you will process every cell in the range D1400
(in his example), one at a time. The cell being processed at any given point
is referenced by the range variable "c". Inside the loop (between the For
Each statement and the Next statement), you will update a value in a SolverOK
command (presumably, based on the value in the cell referenced by the range
variable "c".) Then you will call SolverSolve to actually run Solver. If you
need to store the result somewhere, do it, then let the loop continue to the
next cell.

Your Solver commands might look something like this:
SolverOk SetCell:="$E$1", MaxMinVal:=0, _
ValueOf:=c.Value, ByChange:="$D$1:$D$400"
SolverSolve

In my example above you are changing the ValueOf argument. Depending what
you want to do you might change a different argument. Look at what you are
changing when you run Solver manually for this process, andyou will see which
argument you need to change programatically.

Hope this helps,

Hutch

 

[Dana DeLouis]

Thanks!!! That did the trick, but now I don't know how to integrate the
macro I just wrote into the program that Howard gave me so it will repeat
itself for the relevant rows:

Sub ForHunRow()
Dim i As Integer
Dim j As Range, c As Range

i = Range("F1").Value
Set j = Range("D1400")

For Each c In j
c.Value = i
Next

End Sub

Hi. Here is a general outline.
Here, I have a function in D1, and the changing cells are in A1:C1.
The loop goes from Row 1 to 10. Hopefully, you can adjust it to your
situation. Not quite what I use, but it should give you some ideas.
In a loop, I find it best to just Reset everything.


Sub Demo()
'//Dana DeLouis
Dim R As Long
Dim Target
Dim ChgCells

SolverOptions AssumeLinear:=True
SolverOptions AssumeNonNeg:=True

For R = 1 To 10 'Row 1 to 10
SolverReset
Target = Cells(R, 4).Address
ChgCells = Cells(R, 1).Resize(1, 3).Address

SolverOk SetCell:=Target, MaxMinVal:=2, ByChange:=ChgCells
SolverAdd CellRef:=ChgCells, Relation:=3, FormulaText:="1"
SolverAdd CellRef:=ChgCells, Relation:=1, FormulaText:="10"
SolverSolve True
Next R
End Sub

= = = = = = =
HTH :>)
Dana DeLouis

 

[Janet]

Thanks!!!!!!!!!!!!!!!!!
--
Janet

The For...Next loop he gave you will process every cell in the range D1400
(in his example), one at a time. The cell being processed at any given point
is referenced by the range variable "c". Inside the loop (between the For
Each statement and the Next statement), you will update a value in a SolverOK
command (presumably, based on the value in the cell referenced by the range
variable "c".) Then you will call SolverSolve to actually run Solver. If you
need to store the result somewhere, do it, then let the loop continue to the
next cell.

Your Solver commands might look something like this:
SolverOk SetCell:="$E$1", MaxMinVal:=0, _
ValueOf:=c.Value, ByChange:="$D$1:$D$400"
SolverSolve

In my example above you are changing the ValueOf argument. Depending what
you want to do you might change a different argument. Look at what you are
changing when you run Solver manually for this process, andyou will see which
argument you need to change programatically.

Hope this helps,

Hutch

 

[Janet]

Thanks!!!!! Very helpful.
--
Janet

Hi. Here is a general outline.
Here, I have a function in D1, and the changing cells are in A1:C1.
The loop goes from Row 1 to 10. Hopefully, you can adjust it to your
situation. Not quite what I use, but it should give you some ideas.
In a loop, I find it best to just Reset everything.


Sub Demo()
'//Dana DeLouis
Dim R As Long
Dim Target
Dim ChgCells

SolverOptions AssumeLinear:=True
SolverOptions AssumeNonNeg:=True

For R = 1 To 10 'Row 1 to 10
SolverReset
Target = Cells(R, 4).Address
ChgCells = Cells(R, 1).Resize(1, 3).Address

SolverOk SetCell:=Target, MaxMinVal:=2, ByChange:=ChgCells
SolverAdd CellRef:=ChgCells, Relation:=3, FormulaText:="1"
SolverAdd CellRef:=ChgCells, Relation:=1, FormulaText:="10"
SolverSolve True
Next R
End Sub

= = = = = = =
HTH :>)
Dana DeLouis
.

 

[Mat]

Hi,
I need to do something very similar to this but,

I need my target cells to be N40:N70
target value is 0
By changing cells are D4070

I may need to extend the target and by changing cells to N100 and D100 (respectively)...is this easy to do?
Thanks,
Mat

 

[Pete]

Hi,
I need to do something very similar to this but,

I need my target cells to be N40:N70
target value is 0
By changing cells are D4070

I may need to extend the target and by changing cells to N100 and D100 (respectively)...is this easy to do?
Thanks,
Mat

snip<

Mat:
This might work for you. Good luck.
http://www.vbaexpress.com/kb/getarticle.php?kb_id=433

Pete

 

[Andy Pappas]

Hello
I am trying to solve a trial and error equation with the solver.
I have seen the code above and tried to solve my problem.
I have reached to the following code:


Sub Height()

Dim R As Long
Dim Target
Dim ChgCells

For R = 1 To 10 'Row 1 to 10
SolverReset
SolverOptions Precision:=0.00001
Target = Cells(R, 6).Address
ChgCells = Cells(R, 1).Address

SolverOk SetCell:=Target, MaxMinVal:="3", ValueOf:="0", ByChange:=ChgCells

SolverSolve True
Next R
End Sub


I have put trial and error equations to cells F1:F10 and i want to set the equation to zero by giving values to the cells A1:A10.
I made it work but :

1. When i change the chgcells reference from cells(R,1) to cells(R,2) so that the values to be placed to the second column it returns the value 0 from B1:B10 (i can;t change the column it opnly works for A column.
2.I can't set the restrictions for e.x.
-1< (each A value) < 1
3. For negative values it doesn't work

 

[Andy Pappas]

Sub IPSOS()
'//Dana DeLouis
Dim R As Long
Dim Target
Dim ChgCells

For R = 1 To 10 'Row 1 to 10
SolverReset
SolverOptions Precision:=0.00001
Target = Cells(R, 6).Address
ChgCells = Cells(R, 1).Address

SolverOk SetCell:=Target, MaxMinVal:="3", ValueOf:="0", ByChange:=ChgCells

SolverSolve True
Next R
End Sub