Dummy Data – How to use the Random Functions
Using collected or known data is the best when developing Excel models, but from time to time this may not be available when you are developing your model.
This post will look at some options for setting up Dummy Data using Excels Random functions.
Variability
Real data displays a range of variability, but this variability is generally within ranges or distributions of ranges of results.
All fields type can contain variability
ie: Country, State Names and Zip/Postal Codes, Maybe large lists but are fixed
Peoples Names, Maybe a large lists but are fixed by local rules
Ages, generally less than 80, never less than 0
Dates: Rarely before 1990 or 1900 in rare cases
Lists: are fixed
Numbers: generally random or conforming to a fixed distribution or known trend
Numbers: may include integers, decimals, negatives, extremely large numbers or all combinations
In generating random lists you will need to choose if you want random data, random data within constraints or random with a distribution. The choice is really yours and should in part be based on what the data is being used for and how accurately it needs to reflect reality.
Techniques
The techniques described below are all shown with a worked example in the attached Examples File or the Excel 2003 Example
Each example is annotated below like (Example 4.). ie: Refer to Example 4 in the above example files.
Dates
Setting up Random Dates is a simple process using the Date function.
=Randbetween(StartDate,EndDate)
Dates in a Range of Years
=Randbetween(Date(2000,1,1),Date(2011,12,31))
Will give a list of Random dates between 1 Jan 2000 and 31 Dec 2011 (Example 1.)
(Thanx Mike W)
Dates in a Month
=Date(2010, 6, Randbetween(1,30)
Will give a list of Random dates between 1 June 2010 and 30 June 2010 (Example 2.)
Don’t worry that the above formula (Example 1) can actually produce a 31 Feb 2005, the Date function will happily convert that to 3 March 2005 (Example 3.)
Dates within a Date Distribution
=DATE(2011,7,NORMINV(RAND(), 0,60))
Will give a list of Random dates between approximately 1 Jan 2010 and 31 Dec 2010, with a mean of July 1 and standard deviation of 2 Months (60days) (Example 4.)
Where NORMINV(RAND(), 0,60) will return values between -180 and +180, 99.7% of the time
Text Fields
Dependant on how many items in the list you require there are 3 techniques available
Choose
For small lists of less than 6 to 10 items you can use a simple Choose function (Example 5.)
=Choose(Randbetween(1,6),”Item 1″, “Item 2”, “Item 3”, “Item 4”, “Item 5”, “Item 6”)
VLookup
Using VLookup (Example 6.)
=Vlookup(Randbetween(1,List Length), List, 2)
Index
Using Index (Example 7.)
=Index(List, Randbetween(1, Counta(List) ))
Numbers
Small Random List of Numbers
Random from a small list of numbers (Example 8.)
=Choose(Randbetween(1,6), Numb 1, Numb 2, Numb 3, Numb 4, Numb 5, Numb 6 )
Note that the numbers:
- Don’t have to be in any order,
- Can be integers, negatives or contain decimals
- Can be repeated
eg: =Choose(Randbetween(1,6), 18, 21, -19, 36.4, 18, 24)
Random Integers
Return Integers between Start and Finish (Example 9.)
=Randbetween(Start, Finish)
=Randbetween(50, 100)
Will return an Integer between 50 and 100
Random Numbers
=Rand()
Will return a random number between 0 and 1
=Round(Rand()*100, 2)
Will Return Numbers between 0 and 100 with 2 Decimal places (Example 10.)
Random Numbers Based on a Distribution
=Norminv(Rand(), Mean, SD)
Will return a random number between 0 and 1 based on a distribution of Average = Mean and Standard Deviation = SD
=Norminv(Rand(), 50, 17)
Will return a random number between 0 and 100 based on a distribution of Average = 50 and Standard Deviation = 17, (Example 11.)
Random Numbers Fitting a Trend
If your distribution has to match a trend add a Random component to the Trends equation (Example 12.)
Y=mX+c
= rand() * X + rand()*5
= rand() * A2 + rand()*5
True/False
Choose
Use Choose and Randbetween (Example 13.)
=Choose(Randbetween(1,2), True, False)
If
Use If and Rand (Example 14.)
=If(Rand()<0.5, True, False)
Combination Text and Numbers
The above techniques can be combined to make lists of Alpha Numeric Data
Say your business has a fleet of vehicles (TR=Truck, VN=Van, CAR=Car)
=Choose(Randbetween(1,3),”TR”,”VN”,”CAR”) & Text(Randbetween(1,15),”0#”)
Will randomly choose 1 of “TR”,”VN”,”CAR” and add a random number between 1 and 15 to it format with a leading 0, eg: TR05, (Example 15.)
Other Sources of Data
Random Data
There are a number of web sites where Random Data is available.
http://www.fakenamegenerator.com/order.php
http://www.generatedata.com/#generator
http://www.melissadata.com/lookups/
Open Source Data
There are a number of web sites where Open Source Data is available.
http://www.readwriteweb.com/archives/where_to_find_open_data_on_the.php
Function Used:
Rand: Returns a random number between 0 and 1.
Randbetween: Returns a random Integer between lower and upper limits. Pre Excel 2007 Randbetween was only available through installation of the Analysis Toolpak (Thanx Luke).
Norminv: Returns the inverse of the normal cumulative distribution. That is it returns the X value from a Normal Distribution that has a know Mean and Standard Deviation where the a known cumulative percentage is supplied.
Choose: Choose an item from a list of up to 254 items.
Vlookup: Lookup the matching value from a list and return a data item from another column from the same location.
Index: Retrieve an items from a defined location within a range.
Text: Displays a number as Text with a defined format.
Other Uses of Random Functions
Of course the techniques shown here don’t have to be used for setting up Dummy Data.
One area where Random numbers is used is in Monte Carlo Simulation. This has been discussed at Chandoo.org at Data Tables and Monte-Carlo Simulations in Excel a Comprehensive Guide
Techniques
The techniques described above are all shown with a worked example in the attached Examples File or the Examples File 2003 ver
Limitations in Pre Excel 2007 versions
The Excel function, Randbetween, was only introduced in Excel 2007. As such the exaples above will only work in 2007/10.
However a simple alternative is available
Randbetween(Low, High) = Low + Int(Rand()*(High-Low))+1
Randbetween(90, 100) = 90 + Int(Rand()*10)+1
Examples using this approach are shown in the 2003 Version of the Examples files above.
How have you made Dummy Data or used the Random Functions?
How have you made Dummy Data or How have you used it ?
How have you used Random Numbers in your workbooks ?
Let us know in the comments below:
38 Responses to “Time to showoff your VBA skills – Help me fix ActiveSheet.Pictures.Insert snafu”
I tried your code with 2003, it works.
But, I know Addpicture does not take URLs anymore with 2007 onwards, perhaps its the same with picture.insert as well.
http://support.microsoft.com/kb/928983/en-us
The above link gives the solution as "picture fill in a shape such as a rectangle".
Tried to recreate this, but it worked fine for me. I just took the image of the error you showed in the post. Is there more info that can narrow this down a bit?
Don't know if this helps?
http://www.theserverside.com/discussions/thread.tss?thread_id=47101
Hi
Not sure if this is what you're after, but I just tried this
Sub Macro1()
ActiveSheet.Pictures.Insert("http://www.google.co.uk/intl/en_uk/images/logo.gif").Select
End Sub
Tied a button to it on the sheet and it seems to work; hope this helps a little
Ian
@All.. the issue is in Excel 2007. In 2003 ActiveSheet.Pictures.Insert seems to work fine. Unfortunately, I have design this in Excel 2007.. that is why I posted it here..
v2
Sub Macro1()
Set n = ActiveSheet.Pictures.Insert("http://www.google.co.uk/intl/en_uk/images/logo.gif")
With Range("c12")
t = .Top
l = .Left
End With
With n
.Top = t
.Left = l
End With
End Sub
Ian
That didn't come out very well. This positions at c12, so can change easily:
Sub Macro1()
Set n = ActiveSheet.Pictures.Insert("http://www.google.co.uk/intl/en_uk/images/logo.gif")
With Range("c12")
t = .Top
l = .Left
End With
With n
.Top = t
.Left = l
End With
End Sub
Works OK in 2007
Ian
The above codes work fines to my EXCEL 2007. Thanks.
Chandoo:
Try 'ActiveSheet.Pictures.Insert'
With ActiveSheet.Pictures.Insert("C:\Example.png")
.Left = ActiveSheet.Range("A1").Left
.Top = ActiveSheet.Range("A1").Top
End With
activesheet.pictures.insert "C:\Documents and Settings\Jon Peltier\Desktop\2007 stuff\insert_charts_2007.png"
Works for me in 2003 SP3 and in 2007 SP2.
Check the URL, and make sure you have internet connectivity.
What also works, and is newer (pictures.insert was supposedly deprecated in '97):
activesheet.shapes.addpicture "C:\Documents and Settings\Jon Peltier\Desktop\2007 stuff\insert_charts_2007.png", false, true, 200,200,100,100
Unfortunately you must specify dimensions (the last four arguments) and you don't necessarily know them. But the picture size is still related back to the original picture size, so you could use scaleheight and scalewidth to fix this.
Chandoo: I just re-read your post.
The code I posted works for me. However, I'm using a local picture. If you try to add a picture from the web, this won't work.
I remember solving this problem before by adding a rectangle shape first, then using the Shapes.AddPicture method to get a picture from the web.
I'll find that code and post it here.
Some more updates... The code "ActiveSheet.Pictures.Insert (path)" works fine in Excel 2007 at home. Strange it failed miserably on my work laptop. Do you think this has got something to do with SP2 of MS Office 2007 or something like that?
@Ian, Jon: Thanks for the code snippets. I guess I will use my home installation of excel to do this.
Chandoo:
Try this on your work laptop:
Sub test()
ActiveSheet.Shapes.AddShape msoShapeRectangle, 50, 50, 100, 200
ActiveSheet.Shapes(1).Fill.UserPicture _
"http://www.datapigtechnologies.com/images/dpwithPig6.png"
End Sub
FYI:
http://support.microsoft.com/kb/928983/en-us
I didn't mean to post code with a local file, because both approaches worked with an internet image as well. This is in Excel 2007 SP2.
activesheet.pictures.insert "http://peltiertech.com/images/2009-07/col_area_noblanks.png"
Jon: Looks like I have SP1 on my client machine! I wasn't paying attention.
Just checked my home computer where I have SP2, and you're right...looks like they fixed it.
I didn't even bother testing in SP1, though I could if anyone cares enough.
I'm afraid I don't have a solution, but I find it remarkable that after attaining a certain status in the Excel world, Chandoo does not need to post on an Excel discussion forum to get help for an Excel problem. Instead, he posts on his blog and all the gurus come rushing to his help.
Isn't Web 2.0 great?
Teylyn - I saw Chandoo's tweet first, and followed the link back to his blog.
@Mike.. thank you. I have seen the fill rectangle solution before posting the query here. For that matter, I have also tried the solution of embedding a browser control on a spreadsheet. both of these seemed a bit extreme. That is why I have asked it here.
But I guess I will end up using it if I had to build this in work laptop.
@Teylyn: I have thought of posting this in a forum. (Unfortunately I have not been to any excel group in the last 5 years. Last time I was active was when I built a jave based excel sheet construction solution using POI.HSSF classes of Apache... ) After searching for a few hours, I found several forum posts where others had same problem and the solution recommended (using .left and .top parameters) is not working for me. Incidentally most of these solutions are from a certain Jon Peltier 😛
I thought may be the problem is interesting for fellow blog readers. So I posted it here.
Hi,
Adapting the code in the question,
[code]
Sub InsPicture()
pPath = "http://chandoo.org/images/pointy-haired-dilbert-excel-charts-tips.png"
With ActiveSheet.Pictures.Insert(pPath)
.Left = Range("a1").Left
.Top = Range("a1").Top
End With
End Sub
[/code]
Seems to work fine
Looks like it was a problem in 2007 up to SP1, which was corrected in SP2.
@Jon.. seems like the case. I just checked the version at work laptop. it is 12.0.6331.5000 (SP1).
Thank you so much every one. I really appreciate your time and suggestions in solving this.
Glad to help. I couldn't understand why something so straightforward wasn't working.
Hi All
Is there a way of inserting a motion clip eg animated gif or swf or flv?
Thks
You can insert animated GIFs by inserting them in a browser control through VBA. For other types of movies, I can guess you can insert them as clip art.
I WANT THE INSERT PICTURE BY USING COADING
so currently i was struggling same as you, chandoo, with the insert picture method in excel 2007/10 from an url and came along your thread here.
so i re-designed the code on the addshape method as mike was suggesting it and all of the sudden it works just fine.
thanks alot to you guys, you were a great help
a big salut from switzerland
Hi guys,
I need help copying and pasting an image with the path in a cell.
I leave the code.
And thank you very much!
Sub Copiarimg()
Dim pic As Picture
With ActiveSheet
Set pic = .Pictures.Insert(Range("f2").Value)
With .Range("e9:g22")
pic.Top = .Top
pic.Left = .Left
pic.Width = .Width
pic.Height = .Height
End With
End Sub
I've played around with the approaches in these comments, and the code below is what I've come up with. The ImagePath can be a local file or a URL. As Jon mentioned above, the trick is to set an arbitrary value for the width and height, then call the ScaleWidth and ScaleHeight methods afterward to reset the picture to its original size. Once the LockAspectRatio property is set, you can change the picture width and the height will automatically scale (or vice-versa).
Sub AddPictureToRange(TopLeftCellAddress As String, ImagePath As String)
Dim pic As Shape
Dim l As Single, t As Single
Dim temp As Single
l = Me.Range(TopLeftCellAddress).Left
t = Me.Range(TopLeftCellAddress).Top
temp = 10# ' arbitrary value
Set pic = Me.Shapes.AddPicture(ImagePath, msoFalse, msoTrue, l, t, temp, temp)
pic.ScaleHeight 1#, msoTrue
pic.ScaleWidth 1#, msoTrue
pic.LockAspectRatio = msoTrue
End Sub
I need some help with inserting pictures. I have an excel file with a column of item numbers next to this row I want to insert a picture of this item. The pictures are coded with the item number so I tried to insert it with one of the codes above:
Sub InsPicture()
pPath = "http://img.bricklink.com/P/80/55236.gif"
With ActiveSheet.Pictures.Insert(pPath)
End With
End Sub
That worked but I need to do that for every row separtly.
So I tried in the code
pPath = "http://img.bricklink.com/P/80/"&Text(a1;"#")&".gif"
But that gives errors.
Anybody ideas?
Hi Nicholas, I used your solution in a related problem in Excel 2003 and it worked flawlessly..thank you!
Hi Mike Alexander,
Your solution with some changes was helpful in my problem in XL 2007, thanks.
Hi,
thanks all. In addition, I had a problem with multiple pictures inserting (every new picture replaced the prior one). I've changed it a bit, may be helpful..
Sub test()
ActiveSheet.Shapes.AddShape msoShapeRectangle, 50 , 50, 100, 200
ActiveSheet.Shapes(1).Fill.UserPicture _
"http://www.datapigtechnologies.com/images/dpwithPig6.png"
ActiveSheet.Shapes(1).Copy
ActiveSheet.Paste
End Sub
Try this instead:
Sub test()
ActiveSheet.Shapes.AddShape msoShapeRectangle, 50 , 50, 100, 200
ActiveSheet.Shapes(ActiveSheet.Shapes.Count).Fill.UserPicture _
"http://www.datapigtechnologies.com/images/dpwithPig6.png"
End Sub
Thanks to everyone, this thread has been very helpful. However, image inserting still doesn't work quite as expect for me.
While I can get a picture inserted into an Excel 2010 worksheet using either:
1) ActiveSheet.Shapes(ActiveSheet.Shapes.Count).Fill.UserPicture...
2) ActiveSheet.Pictures.Insert(pPath), and
3) Shapes.AddPicture...
unfortunately the images all insert with a display size determined not by the actual pixel dimensions of the image but by the dpi resolution.
So for example, if I insert two copies of the exact same 600x600 pixel image, one with a 300dpi resolution and the other with 72dpi, they display at vastly different sizes on screen.
While this might be intended behaviour for Excel in order to maintain a WSYWIG printing layout, I actually need a way to insert the image based on the the actual pixel dimesnsions and ignoring the dpi resolution.
Any help appreciated.
Thanks
Kez
Not doing an intentional bump, but realised I posted in rely to one of the repsonses here instead of to the main thread, so reposting.
=====
Thanks to everyone, this thread has been very helpful. However, image inserting still doesn’t work quite as expected for me.
While I can get a picture inserted into an Excel 2010 worksheet using any of the below methods:
1) ActiveSheet.Shapes(ActiveSheet.Shapes.Count).Fill.UserPicture....
2) ActiveSheet.Pictures.Insert(pPath), and
3) Shapes.AddPicture....
unfortunately the images all insert with a display size determined not by the actual pixel dimensions of the image but by the dpi resolution.
So for example, if I insert two copies of the exact same 600×600 pixel image, one with a 300dpi resolution and the other with 72dpi, they display at vastly different sizes in Excel on screen.
While this might be intended behaviour for Excel in order to maintain a WYSIWYG printing layout, I actually need a way to insert the images based on the the actual pixel dimesnsions and ignoring the dpi resolution.
Any help appreciated.
Thanks
Kez
Well, answered my own question 🙂
For those who might be interested, you can use this function:
Public Function GetPicDims(strFilePath As String, strFileName As String) As String
GetPicDims = CreateObject("Shell.Application").Namespace((strFilePath)). _
ParseName(strFileName).ExtendedProperty("Dimensions")
End Function
to get the dimensions of the image you want to insert. Then you can parse the return string and use the width and height values to add a rectangle shape of the appropraite size, like:
ActiveSheet.Shapes.AddShape msoShapeRectangle 50, 50, iWidth, iHeight
which you then fill with the picture:
ActiveSheet.Shapes(ActiveSheet.Shapes.Count).Fill.UserPicture "c:\temp\test.jpg"
This way the picture gets inserted using the pixel dimensions and the (print) resolution gets ignored.
If desired, the GetPicDims function can be made more generic to get other ExtendedProperties.
Regards
Kez