VBA Project help and overflow error

[p45cal]

..moving swiftly on:
I'm guessing that the cup is cylindrical, like the straw so you need to use similar formulae to calculate the volumes of each.
Regarding your cup volume calculation:
Volc = Pi * 16 * Cuph
If you already know how to calculate the volume of a cylinder then I reckon that the 16 in the formula means the cup has a radius of 4. You have Dimmed a variable Rc, but you've neither set nor used it. You should set its value somewhere, then instead of 16 in the formula do something to Rc in there.

Now your formula for the straw's volume should be similar. Rather than
Vols = Rs * Cuph
you should see Pi in there somewhere, as well as doing a bit more with Rs.

When you've finished, both formula should look very similar, the only difference being two substitutions of lower case c for lower case s.

Your formula for the new water level
Cuph = Volc / (Pi * 16) will work fine, but only if the cup's radius is 4. Again, it might be an idea to use Rc in there, as above.

If all that's put right, you're looking for results where for a straw radius of 0.2 you expect some 1200 dips required.

Your graphs might look like:
Attachment 3598

[GTO]

...then I reckon that the 16 in the formula means the cup has a radius of 4....

Your formula for the new water level
Cuph = Volc / (Pi * 16) will work fine, but only if the cup's radius is 4....

If all that's put right, you're looking for results where for a straw radius of 0.2 you expect some 1200 dips required...

Greetings Pascal,

If I am mis-reading, I'll certainly ask forgiveness/apologize. From my current understanding, I respectfully/humbly disagree.

If the diameter is 16, the radius is 8.

The OP's functions's formula construction appear incorrect to me, as the radius is not being squared.

reference:
[vba]
Function CupVolume()
Volc = Pi * 16 * Cuph

End Function
[/vba]
I guessed at the 16 being the radius and got 19k+ dips for the .2 straw.

Mark

[p45cal]

If the diameter is 16, the radius is 8.

Quite true.. but I didn't think 16 was the diameter, rather I guessed that 16 was supposed to be the square of something.. perhaps 4.

It was only mdmckillop who used the word diameter, Goallie11 always used radius, referring to both cup and straw, and the variable names Rs and Rc (the latter currently unused) imply radii rather than diameters.

But this has already given perhaps too much info, so to Goallie11, see here.

[mdmackillop]

I did use the diameter in the description, and in the context, consider it the correct figure to use as a constant. I've never heard of a cup size being measured by the radius. The calculation would of course be revised to use this new constant. As an exercise, I would leave this to the student to figure out.

[Goallie11]

Sorry it's taken me so long to respond, I was out last night.

But to answer some questions, yeah the radius of the cup is 4, with 16 being the square. That gives the formula of Pi * 16 * Cuph for the volume of the cup.

The cup is cylindrical and so is the straw. And oh man I can't believe I missed the pi in the calculate for the straw volume! It worked so I just never looked at it. That shows you always have to be vigilant.

So I went through and changed everything and also added a new formula as we also have to graph an analytical vs numerical for Rs = 0.5 chart. This has been added at the bottom, and I believe everything works fine now.

GTO you were right, I cleared off the numbers in the workbook and it made it small enough. So it's finally attached now for everyone to see!

[mdmackillop]

Regarding Single and Double and the 0.5 error, refer to this post

[Goallie11]

What 0.5 error are you talking about? I don't want to sound ignorant but it looks to me like it works fine. The little differences in rounding don't affect this assignment too much.

[GTO]

Quite true.. but I didn't think 16 was the diameter, rather I guessed that 16 was supposed to be the square of something.. perhaps 4.

My utter bad, you were obviously spot-on with what the OP was doing. (I suppose the absurdity of a 16 or 32 inch wide cup should have struck me harder... )

Goallie,

Very nice progress

Mark

[mdmackillop]

I copied your code and put it in place of mine and it works but it only goes to Rs = 0.45 for me, where it needs to go until Rs = 0.5

I don't think it should do that as there is still the While Rs <=0.5 loop in there. What would cause it to stop there instead of continuing?

I was meaning this issue, and the reason it occurred.

[Goallie11]

Oh yeah, changing Rs to double solved that issue.

Thanks GTO, I couldn't have done it without the help of this forum, all you guys are great.

[Blade Hunter]

There is no advantage in Interger over Long, so always use Long

I disagree, using a long where only integer is needed is a waste of memory space. Being that the OP is learning I think it is good practice to push them towards being memory efficient.

Just because we have gigs and gigs of ram these days, doesn't mean we should be wasteful, this is why modern PC's need constant reboots and the like because of corners being cut.

[p45cal]

It may not be as straightforward.. storage space/speed/overhead; see
here and here and here and here.

I disagree, using a long where only integer is needed is a waste of memory space. Being that the OP is learning I think it is good practice to push them towards being memory efficient.

Just because we have gigs and gigs of ram these days, doesn't mean we should be wasteful, this is why modern PC's need constant reboots and the like because of corners being cut.

[Blade Hunter]

It may not be as straightforward.. storage space/speed/overhead; see
here and here and here and here.

Hmmmm, I could have sworn I already replied to this.

Thanks for the links, I have learned something .

I stand corrected .

Cheers

Dan