My project is kind of a simulation. It computes the formulas in a set of worksheets repeatedly with differing input data. These worksheets are created for each run from scratch by the VBA macro based on templates, assembling blocs of cells with formulas like LEGO bricks. The workhorse of the simulation is the “worksheet.calculate” method. It does not work anymore since a while, and I could not find the reason. The code lines below are those, where execution of the macro gets caught in an “eternal” loop. Execution of the code line “ws_C_S.Calculate” takes forever. The task manager shows Excel using 50% to 90% of CPU in this phase and the computer starts to make remarkable noise after a few minutes (may be due to heavy disk operations). I am running Office 365 under Windows 10 64-bit and set the Option explicit option in every module. The saved workbook appears to be fine. It behaves okay when opened stand-alone by hand.
Suggestions how to fix this would be highly appreaciated.
Here are the code lines, where execution gets caught:
' create a fresh CalculBook with 1 worksheet and save it as xlsb file
Set wb_C = Workbooks.Add(xlWBATWorksheet)
Set ws_C_S = wb_C.Worksheets(1)
ws_C_S.Name = ws_S_Name
wb_C.SaveAs Filename:=CalculBookFullName, FileFormat:=xlExcel12
MsgBox "going to calculate the SystemSheet in the CalculBook"
' Here I had originally a number of Copy > PasteFormulas operations
' I removed them piece by piece because the final calculation failed
‘ I hoped to identify some faulty formulas this way
' But the error continues to happen even without any formulas in the worksheet!
ws_C_S.Activate ‘ it tried it with and without activating the worksheet, leading to the same result
ws_C_S.Calculate
MsgBox "SystemSheet calculated"
I've tried every suggestion on this site to make my macro faster.
Halt calculations
Disable the screen updating
Disable status bar updating
Telling the Excel to ignore events
and so much more. Even in loops, I've tried many methods of making my macro smooth.
And I saw an article that I can use colon to make a multiple lines of codes into single line.
From:
Dim x as Integer
x = 1
If x = 0 Then
Exit Sub
End If
To:
Dim x as Integer: x = 1: If x = 0 Then Exit Sub
Does making some codes in the same line makes the macro faster?
No, writing the code on the same line does not make the code run faster.
Code can be slow because of inefficient coding techniques, like looping through all cells in a column, reading each cell, calculating it, and writing the result back to another cell in each step of the loop.
Writing that code in one line is possible, but it won't make the code run faster.
What WILL make the code run faster is reading the data range into an array, then looping over the array, writing the output of any calculation into another array and then finally writing the result array back to the spreadsheet as one write operation.
This is simply a different line break and does not affect execution time.
You already noted a couple of tricks you applied:
Application.ScreenUpdating = False
Application.DisplayAlerts = False
Application.Calculation = xlCalculationManual
Application.EnableEvents = False
Since you haven't posted full code and "Please optimize my code" is not a question, there's the following general tips to speed up Execution:
When referencing the same Object multiple times in a row, use With and End With instead. This is faster than specifying the full path to the object each time, since it prevents certain IO operations to access the right block in memory.
Use as little references to Worksheet / Range objects as possible, in general. A lot of times it's faster to use an Array than a Range. See Chip Pearson's article on this.
Looping is slow. Using native functions is faster. Make use of Autofilter instead of checking each cell, for example.
Do not use Copy and Paste, instead use the Destination parameter of the Copy method
Declare your objects as accurately as possible: Use Dim ws As Worksheet instead of Dim ws or Dim ws As Object.
Never use .Select and .Activate - See this Question
No, such changes does not boost Your code.
It also depends what Your macro do, but my case was that I needed to use sth similar to vlookup in my code, so at the first version I used ForEach loop and if statment - when I was to match 10 000 records with about 3k values it took about 15 minutes. So I decided to use dictionary (reference does not break acro on other machines) and it really boost my code. Now 20 k records with 6k values takes about 2 minutes.
Most of the cells in my worksheet receives RTD data once per second and a lot of calculations are done when the data is refreshed. It's becoming really slow. If I set Application.ScreenUpdating to false, does it mean even if the most recent data is not refreshed on the screen, but the functions will still be calculated using the latest values?
For example, I have cell C1:C300, which is updated once per second. Another column D1:D300 uses the values from C1:C300 to compute some formula. Now if I set the Application.ScreenUpdating to false but Calculation Mode to automatic, will I speed things up without causing any problems? I mean, I can't tell from the screen whether calculations in D1:D300 are calculated using the new data in C or not?
Thanks!!
Application.ScreenUpdating=false does not affect Automatic calculation so thats OK. But Application.screenUpdating automagically gets switched back on when your VBA exits back to Excel. So it might be better to control both Calculation and Screenupdating from VBA
I have a rather large workbook that takes a really long time to calculate. It used to be quite a challenge to get it to calculate all the way, since Excel is so eager to silently abort calculation if you so much as look at it.
To help alleviate the problem, I created some VBA code to initiate the the calculation, which is initiated by a form, and the result is that it is not quite as easy to interrupt the calculation process, but it is still possible. (I can easily do this by clicking the close X on the form, but I imagine there are other ways)
Rather than taking more steps to try and make it harder to interrupt calculation, I'd like to have the code detect whether calculation is complete, so it can notify the user rather than just blindly forging on into the rest of the steps in my code. So far, I can't find any way to do that.
I've seen references to Application.CalculationState, but the value is xlDone after I interrupt calculation, even if I interrupt the calculation after a few seconds (it normally takes around an hour).
I can't think of a way to do this by checking the value of cells, since I don't know which one is calculated last. I see that there is a way to mark cells as "dirty" but I haven't been able to find a way to check the dirtiness of a cell. And I don't know if that's even the right path to take, since I'd likely have to check every cell in every sheet.
The act of interrupting calculation does not raise an error, so my ON ERROR doesn't get triggered.
Is there anything I'm missing? Any ideas?
Any ideas?
I think the trick you need to implement (if you're application runs in Excel 2007 or later) is to handle this with the Application.AfterCalculate event, which is raised after both calculation is complete and there are no outstanding queries.
If you've never worked with events in VBA before, there is a good overview from cpearson.com.
The (MSDN) solution by Charles Williams above worked for me where I had 1000's of VLOOKUP's that neeeded to recalculate as the code was changing the lookup value because of an iteration loop. Results were skewed as calculations were not running to 100% completion.
At the beginning of my subroutine the code executes
Application.Calculation = xlManual
This eliminated unnecessary calculations by Excel until I was ready.
Now at the critical point the code executes
Application.Calculation = xlAutomatic
ThisWorkbook.ForceFullCalculation = True
Application.Calculate
Having forced Excel to perform a full calculation, the code could then saved the result and move onto the next iteration ... but before doing so
ThisWorkbook.ForceFullCalculation = False
Application.Calculation = xlManual
Remembering at the very end
Application.Calculation = xlAutomatic
I've never actually used it but I think this might work to prevent calculation from being interrupted.
Application.CalculationInterruptKey = xlNoKey
I think I'm hearing that you need a way to monitor whether each step within the calculations being performed was executed.
Assuming that you're not interested in re-engineering the workbook to use methods that are easier to track than spreadsheet calculations (such as volatile calculations within VBA or Pivot Tables), this may work for you:
Within VB, you can utilize .EnableCalculation and .Calculate to set an entire worksheet as "Dirty" (needing calculation) and then recalculate. The key difference between this and your current process is that we will perform these actions one worksheet at a time in manual mode. By initiating the calculations one worksheet at a time from within VBA, you will be able to perform additional intermediate actions that can be used to track how far you got in the calculation process.
Please note that this approach assumes a fairly linear workbook structure such that your workbook will produce the correct results if we first recalculate Sheet1, then Sheet2, Sheet3, and so on, in whatever order you wish. If your formula dependencies are more "spaghetti" than linear, this probably won't work for you. It also assumes you are working in Excel 2000 or later.
For example, you could write a VBA routine that accomplishes the following steps.
You will need to know your dependencies in order to know which calculations must come before others, and start with the worksheet in a "clean" state where no calculations are currently pending.
Step 1: Set the active sheet to the first worksheet where recalculation is needed
Step 2: Set the calculation mode to manual as follows:
Application.Calculation = xlCalculationManual
Step 3: "Dirty" the entire active sheet as follows:
With ActiveSheet
.EnableCalculation = False
.EnableCalculation = True
Step 4: Initiate a recalculation for this worksheet only (not the entire workbook) using:
.Calculate
End With
Note that if the calculation mode were set to automatic, Step 3 would initiate a re-calculation across the entire workbook. By using manual mode and With, we are constraining that calculation to the current sheet.
Now you have dirtied and re-calculated the first sheet (hurray!). Now, by embedding Steps 3 and 4 above into a For/Each or For/Next loop, you can repeat the process for each worksheet in your workbook. Again, make sure you know the order in which your worksheets need to be calculated (if an order is needed).
Now for the big finish - by creating a counter variable within your loop, you can track how far you got in the calculations by updating your counter variable value each time you complete a worksheet calculation. For example, after you recalculate a worksheet, you can set the counter value to current value + 1 and store the results either in a global variable (so that it will persist even after your VBA routine ends), or in a cell within your worksheet. That way, you can check this value later to see how many worksheets were updated before the calculations finished or were interrupted.
If you have relatively few worksheets in your workbooks, the same approach could be applied to one range at a time rather than a sheet.
I won't go into detail about how to construct a "counter", loops, or global variables here, but if needed, this information can be easily found using your favorite search engine. I would also highly recommend re-enabling automatic calculations once you are done as it is easy to forget that it's been set to manual mode.
I hope this works for you - for more information on calculation modes and recalculation, this is a helpful link:
http://msdn.microsoft.com/en-us/library/bb687891.aspx
Perhaps the following would work:
Do Until Application.CalculationState = xlDone
DoEvents
Loop
Can't say I've tested it, nor that I know how robust the functionality of Application.CalculationState really is to determine whether 'complete' calculation occurred, as opposed to something interrupting the process and flagging the calculation state as done.
Private sub SomeCodeThatGeneratesFormulas
Application.Calculation = xlCalculation.xlCalculationManual
'...Some formulas are copied here'
Application.OnTime DateTime.DateAdd ("s",.01,DateTime.Now), "Module1.CalculateFullRebuildAndSubsequentSteps" 'By using Application.OnTime, this method will be called in a way that locks the end-user out of providing inputs into Excel until the calculation itself is complete.
end sub
public sub CalculateFullRebuildAndSubsequentSteps
Application.CalculateFullRebuild
'...Do next steps, i.e. paste as values'
end sub
On the status bar, right hand side, it will say Calculating (N processors) X% (where N is the number of processors on your computer and X% is how much it has completed) when recalculating. If you don't see text there, it's not recalculating.
I'm using Office 2010, but it should be there in all versions. It's just kinda subtle so it's easy to miss.
Arrays in Excel can be a bit stupid. That is that in order to accomplish some tasks people avoid to use intermediate columns/rows to store (temporary) data, so arrays have to recalculate staff from the beginning every time, thus getting really slow. My Suggestion would be:
fix arrays to avoid multiple searches. Use hidden cells or even hidden sheets
Avoid using A:A and rather use A1:A1000 specially in excel 2007 or later
use formulas to equal zero or error (ex: NA()) while previous items aren't calculated, so you can clearly see if an operation is done at all.
some VBA could be used to inject formulas in place one step at a time, perform calculations, then proceed to next step, but this could mean lots of work...
Does the size of excel workbook effect the running of a VBA code? I have written a VBA code into a excel workbook whose size is 200 MB.The excel workbook has the browse button and these browse button picks another Excel file and performs operations and write backs some of the needed contents to the 200 MB size file. But these operation is too slow taking 8 to 13 min. These excel workbook contains charts, graphs and more modules and 16 sheets and pivot tables lots of stuff.(will these effect to run the vba code?)
But the same code I have written to another new excel workbook which is of size 200KB with the same browse button and all that stuff and here it took 4 seconds to finish. I wonder whats going wrong. Using for loops is harmful for a big file but I cannot perform my operation using without a loop in my code.If for loop is harmful then it should even effect 200KB size but no danger with that! what I have to do now?
Make sure you have used Application.ScreenUpdating=False and Application.Calculation=xlManual before the code that writes to the workbook. (Then reset them at the end).
Also there is a big overhead on each read and write to a Range, so its usually much faster to read a large block of data into a variant.
Dim vArr as Variant
vArr=Worksheets("Sheet1").Range("A1:Z9999").Value2
'Manipulate the resulting array.
For j = LBound(vArr) To UBound(vArr)
For k = LBound(vArr,2) To UBound(vArr,2)
vArr(j,k)=vArr(j,k)*2
Next k
Next j
'And then write it back to its destination.
Worksheets("Sheet2").Range("A1:Z9999")=vArr
Even the mere action of reading and/or writing the file takes a significant amount of time in such a large file, many intermediate operations may be affected as well.