Timing a Calculation (97 SR-2)

**chipshot** · 2003-10-15 13:13

In a previous thread I started about the benefits of declaring your VBA variables, one of the stated benefits is faster execution time. While I believe this to be true, I would like to run a little test to see how much speed can be gained by proper declaration of variables.

I have been working with a spreadsheet where I have a user-defined function that is entered in thousands of cells. As needed, I hit ctrl-alt-f9 to force a total recalc and the whole thing takes about 15 minutes. I know how to time the execution of a Sub by capturing the value of NOW at the beginning and end of the Sub, but is there a way to time a ctrl-alt-f9?

**HansV** · 2003-10-15 13:24

I'm not entirely sure about this, others will correct me if I'm wrong. I think that Application.CalculateFull is the VBA equivalent of Ctrl+Alt+F9. So you could create a procedure that stores the time, executes the above instruction and then checks the time again.

Note: I use the Timer function to measure execution time. It returns a value of type Single that represents the number of seconds since midnight.

Dim sngTime As Single
sngTime = Timer
Application.CalculateFull
sngTime = Timer - sngTime
MsgBox "Execution took " & Format(sngTime, "0.00") & " seconds"

**chipshot** · 2003-10-15 13:52

Hans,
My VBA doesn't seem to recognize calculatefull. I've previously looked for a VBA equivalent to ctrl-alt-f9, but I've never found one.

The TIMER function is cleaner than using NOW. However, it seems TIMER won't work if the execution of your code is executing at midnight. <img src=/S/doze.gif border=0 alt=doze width=15 height=15>

**HansV** · 2003-10-15 13:57

I'm using Excel 2002. CalculateFullRebuild is listed as a new method in the online help, but CalculateFull isn't. Perhaps it was introduced in XL 2000?

You could take midnight into account when using Timer: if the second time is less than the first one, add 86400 (= number of seconds in one day) to the result. But I must admit that I never bother.

**JohnBF** · 2003-10-15 16:55

CalculateFull was introduced in XL 2000.

**HansV** · 2003-10-15 18:19

Thanks for the confirmation, John.

**chipshot** · 2003-10-15 18:42

So, is there any solution for me and my XL97?

**sdckapr** · 2003-10-15 18:47

This should work in VB

<pre>SendKeys "%^{f9}", True</pre>

Steve

**JohnBF** · 2003-10-15 18:51

In Xl 97 just:

Application.Calculate

**sdckapr** · 2003-10-15 20:11

I think this is just an F9 calc, not a full-blow ctrl-alt-f9

Steve

**JohnBF** · 2003-10-15 21:29

Right, I don't recall that Ctrl-Alt-F9 did anything different from F9 in XL97, but maybe I remember incorrectly. I'll check the old machine with 97 at home.

**sdckapr** · 2003-10-16 01:19

F9 does a simple calc and if excel doesn't believe anything has changed it won't update.
Ctrl-Alt-F9 forces a recalc on all.

It becomes essential with some user-defined functions that are based on hidden rows, cell colors, etc (things excel does not believe will trigger different values) to make sure they are updated.

Steve

**chipshot** · 2003-10-16 01:23

I've never tried to figure what types of user-defined functions require ctrl-alt-f9, but whenever I use a UDF, I don't trust my results unless I do a ctrl-alt-f9.

BTW, the Sendkeys function seems to do the trick. Thanks for solving a longstanding gripe.

**sdckapr** · 2003-10-16 01:40

This site has some good general information on calculations in excel.

Steve

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