I was working with a group of learners on a Science write up and we thought it would be a good idea to take an image of the practical set up and plonk into into Excel.  This would aid our write up, or for some, replace a long winded explanation.

Excel doesn’t have a naive “insert image from webcam” button, so we had to build one.

Download Insert WebCam into Excel Workbook

Inserting a webcam image into Excel

(The quality of the image captured is 640×480 at the camera resolution – this looks pixelated due to the compression to animated GIF)

An extensive search on Google discovered that this is not a unique question, but the solutions are few and far between.  Eventually I happened upon the use of AVICAP32.DLL (only in 32 bit Windows – I’m on Windows 8 and it works fine.  This should work in all Windows XP+ I believe).

The code:

Option Explicit
 
Const WM_CAP As Long = &H400
Const WM_CAP_DRIVER_CONNECT As Long = WM_CAP + 10
Const WM_CAP_DRIVER_DISCONNECT As Long = WM_CAP + 11
Const WM_CAP_EDIT_COPY As Long = WM_CAP + 30
Const WS_CHILD As Long = &H40000000
Const WS_VISIBLE As Long = &H10000000
 
Declare Function SendMessage Lib "User32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
 
 
Declare Function DestroyWindow Lib "User32" (ByVal hndw As Long) As Boolean
 
Declare Function capCreateCaptureWindowA Lib "avicap32.dll" (ByVal lpszWindowName As String, ByVal dwStyle As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Integer, ByVal hWndParent As Long, ByVal nID As Long) As Long
 
 
Declare Function capGetDriverDescriptionA Lib "avicap32.dll" (ByVal wDriver As Integer, ByVal lpszName As String, ByVal cbName As Long, ByVal lpszVer As String, ByVal cbVer As Long) As Boolean
 
Declare Function GetDesktopWindow Lib "User32" () As Long
 
Sub WebCamClip()
 
Dim strName As String
Dim strVer As String
Dim hwnd As Long
Dim iDevice As Long
 
    iDevice = 0
    strName = Space(100)
    strVer = Space(100)
 
    If capGetDriverDescriptionA(iDevice, strName, 50, strVer, 50) Then
 
        hwnd = capCreateCaptureWindowA(iDevice, WS_CHILD, 0, 0, 640, 480, GetDesktopWindow(), 0)
 
 
        If hwnd Then
 
            SendMessage hwnd, WM_CAP_DRIVER_CONNECT, iDevice, 0
            SendMessage hwnd, WM_CAP_EDIT_COPY, 0, 0
            SendMessage hwnd, WM_CAP_DRIVER_DISCONNECT, iDevice, 0
 
            DestroyWindow hwnd
        End If
    End If
ActiveSheet.Range("d3").Select
 
 
ActiveSheet.Paste
Selection.ShapeRange.ScaleWidth 0.5, msoFalse, msoScaleFromTopLeft
Selection.ShapeRange.ScaleHeight 0.5, msoFalse, msoScaleFromTopLeft
 
End Sub

Insert all this code into a new module and create a button on your worksheet linked to Macro WebCamClip.

Click the button and after the Camera has come to life – your image appears inside Excel.

Why is this useful?

Imagine making a series of buttons linked to image boxes, where a user assembles some practical experiment – Click! Evidence.  Takes some results, Click! Evidence.  

 Download Insert WebCam into Excel Workbook

Previously I blogged about using GoogleMaps Api to create a user defined function in Excel to calculate the distance between two postcodes. You can read about that here.

Recently I’ve been working with a colleague to organise a series of HwbMeets (TeachMeet style gatherings coordinated by the Welsh Government).  One thing we needed was to ensure that we got the message out there to the non Twitter teachers who would find such an event useful.

OK, we write to and email each school in Wales letting them know about the events, but nothing beats a phone call. So we got thinking that the best way forward would be to call those closest schools to each meeting and say “Hey, you know what, this is happening 3 miles up the road next week”.

And thats what the G_Distance user defined function is ideal for.  Given the postcode of a venue, I now have a spreadsheet that calculates the distance (on the roads, not as the crow flies) from each school in Wales to that venue.

Now we can target those schools closest to the venues and get a feel for how far teachers are willing to travel.

If you want to grab a copy of my code to calculate the distance between postcodes in Excel – download it here here.

Splendiferous.

Dice rolling is used in school to generate random data, simulate radioactive decay or “to generate data to graph”.

During a visit to a Special School recently we discussed how, during a maths lesson the learners had 1, 2 or 3 dice and were  rolling them, adding up the scores each time and plotting a graph of the results.  The idea to be that with 1 dice, there is no “most common score”, but with 2 dice the most common is 7 and with 3 its 10 and 11.  The students were expected to roll the dice hundreds of times, add up the face values, enter the scores into a tally chart and then draw a histogram of the results.

As you can imagine it was dice wars, with the little cubes being used as missiles round the class.

So, a different way was needed and splendiferous Excel to the rescue.

Consider the face of a dice:

Download the Dice Worksheet

Thinking about the dice face logically we can build up some rules about when each “spot” is active.  So as a class discussion we considered the rules:

• The indicated spot is active when the value of the dice is greater than 1
• The next spot in the same row is never active
• The spot in the top right corner is active when the value of the dice is 4, 5, or 6.  Or when the value is greater than 3
• The lefthand middle row spot is active when the value on the dice = 6
• The center spot is active when the value on the dice =1, 3 or 5.  Or when the value is Odd
• The right hand middle row is active when the value on the dice = 6
• The spot in the bottom left corner is active when the value of the dice is 4, 5, or 6.  Or when the value is greater than 3
• The bottom middle spot is never active
• The right hand bottom corner is active when the value on the dice = 2,3,4,5 or 6.  Or when the value is greater than 1

Creating these rules took 30 minutes of class discussion and was a great example of cooperative learning as it took awhile for everyone to be happy with the wording of the rules AND people kept suggesting new ways of saying the same thing.  However, no dice got thrown.

Converting to Excel

In Excel speak – the DOT is represented by Wingdings font, character 159.  Which is entered into Excel as CHAR(159). Excel can generate random numbers – specifically between 1 and 6 for our dice with the RANDBETWEEN(1,6) formula.

Our statements above can be turned into a series of IF statements dependant on the value of the dice.

Assuming the value of the dice is stored in A1 as A1=RANDBETWEEN(1,6)  the above statements reduce to:

• IF(A1>1,CHAR(159),”") — If A1 is greater than 1, use CHAR(159) or else “” (nothing)
• Leave blank
• IF(A1>3,CHAR(159),”") — If A1 is greater than 3, use CHAR(159) or else “” (nothing)
• IF(A1=6,CHAR(159),”") — If A1 is equals 6, use CHAR(159) or else “” (nothing)
• IF(ISODD(A1),CHAR(159),”") — IF A1 is ODD use CHAR(159) or else “” (nothing)
• IF(A1=6,CHAR(159),”") — If A1 is equals 6, use CHAR(159) or else “” (nothing)
• IF(A1>3,CHAR(159),”") — If A1 is greater than 3, use CHAR(159) or else “” (nothing)
• Leave blank
• IF(A1>1,CHAR(159),”") — If A1 is greater than 1, use CHAR(159) or else “” (nothing)

This took about 15 minutes for the class to work through, but again, no dice thrown.

As the spreadsheet has a RANDBETWEEN statement in it, pressing F9 causes a recalculation and the numbers change.

Extensions

To make 2, 3 or more dice – we just copy the code across for one dice, making sure to set up a new RANDBETWEEN for each dice (so they are different) .

Adding a small bit of VBA to a button, with a little loop makes the dice look like they are rolling.

To view my VBS code (in Excel), press ALT-F11 or access via the Developer Tab

Conclusions

1. Real dice hurt when thrown
2. Focus on computational thinking instead of endlessly rolling dice
3. Learners are capable of some sophisticated thinking if you give them chance.
4. Excel is splendiferous.

Download the Dice Worksheet

So, in the spirit of shameless marketing and eye candy, we are going to create this chart:

This chart has the following “features”:

• The bars are filled with an image related to the content of the chart
• There are no axes – instead the category data (2004, 2005 etc is added inside the bars as a label) and the y-axis being replaced with a data label inside each bar.

Whilst not terribly complex, the chart does need some prior planning.

Create data in Excel:

• It’s important that you don’t label the Year column – leave it blank,
• The “Difference” column is the difference from 100 for each of the data points.  So 100-44 = 56 etc.  
• The Dummy value is a repeat of the actual data (more on that later).

Create a “stacked bar chart”:

Highlight everything in the table above and Insert a stacked bar chart (NOT a 100% stacked).  Use all the defaults.  You will end up with:

Remove the LEGEND and CHART TITLE

Insert Image into Chart Plot Area:

Not all images work – and some just make everything confusing.  Choose carefully.

Format Series

• Select the 2 A*- C Series and reduce the Gap Width to 0% (this will push all the bars together
• Select the 2 A*- C Series and set the series fill to “No Fill” (this will let the image show through)
• Select the Difference Series and set the series fill to “Solid” and 50% Grey
• Select the Dummy Series and change the Series Options to plot on a “Secondary Axis”
• Select the Dummy Series and set the series fill to “No Fill”
• Select the Primary Axis and set the Maximum to 100.  Delete the axis
• Select the Secondary Axis and set the Maximum to 100. Delete the axis
• Select the Category Axis (the dates) and delete it

You should have something that looks like this:

Tidying up:

• Select the Dummy Series and add Data Labels.  Set the Data Label Position to “Inside Edge” (This will put the data label inside the bars at the TOP of the bar
• Select the 2 A*- C Series and add Data Labels.  Set the Label Options to Label Contains Category Name and Positon to Inside Base (This will put the category name at the bottom of the bar)
• Add a Solid 3pt border to the 2 A* – C Series
• Remove the “Major Gridlines” on the Y-Axis
• Add a Solid 2pt border to the Plot Area of the Chart
• Adjust the size and coloration of the fonts for the data labels as needed
• Add chart Title (if needed)

You will end up with:

Questions:

1. Is this more meaningful than a “plain” chart – err No.
   
2. Does it get your message across better – well that depends on what your purpose is
3. Does it look good – that’s for you to decide.
4. Will it look good in a prospectus – again, as above.

A LEN() lets me monitor the length of the Tweet so that I don’t go over 140 characters in total.

Where I run into a workflow issue is with the URL itself.  I don’t want to use the full URL as it will take precious characters from my 140 – so I use a URL shortening service such as Goo.gl. But that means I need to copy, paste into Goo.gl and copy paste back into Excel.  There must be an easier way.

Google lets us access the Goo.gl service via its API.  Log into your Google account and visit: https://code.google.com/apis/console  – towards the bottom, you can choose to enable the URL Shortener API.  With 1,000,000 requests per day, I am sure I’ll never over do it.

Once enabled you need to get your API Key.  This is unique to you, so don’t share it.

In Excel, VBA – Insert a new Module

Now cut and paste this code, to make a new function GetGooglURL

Const API_KEY As String = "YOUR API KEY HERE"
Const BASEURL As String = "https://www.googleapis.com/urlshortener/v1/url"
 
Function GetGooglURL(url As String) As String
 
  Dim xml As Object  ' MSXML2.XMLHTTP60
  Set xml = CreateObject("MSXML2.XMLHTTP.6.0") 
 
  If xml Is Nothing Then Exit Function
 
  With xml
    .Open "POST", BASEURL & "?key=" & API_KEY, False
    .setRequestHeader "Content-Type", "application/json"
    .Send Replace("{""longUrl"": ""http://www.google.com/""}", "http://www.google.com/", url)
  End With
 
  If InStr(xml.responseText, "error") = 0 Then  ' no error occurred
    ' parse out short URL from JSON response
    GetGooglURL = Trim$(Split(xml.responseText, """")(7))
  End If
 
End Function

Using this is simplicity itself.  In cell B2 is the long URL you want to shorten.

C2=GetGooglURL(B2) – sends the long URL to Google for shortening and displays in A2 the short version.

Splendiferous Excel and Web Api to the rescue again.

Excel 2013 can consume that data using the built in WEBSERVICE and FILTERXML  functions.

WEBSERVICE reaches out to “big data” land and pulls into Excel an XML data feed.

FILTERXML extracts specific pieces of information from that feed.

For example:

http://www.theyworkforyou.com provides details on MPs and a searchable database of who does what.  Using their API you can extract that information yourself.

Register for an API Key here (An API key is a unique reference that lets you access the data.  This is free, and it allows the site owner to track who is consuming what from their site.  It also allows them to rescind your key, should you abuse the service).

Once you have your OWN API key, form a URL as follows, and replace with your own API Key:

http://www.theyworkforyou.com/api/getMP?key=APIKEYGOESHERE&output=xml&postcode=np109jn

This returns informantion on the MP for NP109JN:

This is the XML outout – it looks daunting, but its not:

<twfy> is the top level holder inside which all the data is contatined:

<member_id>40424</member_id>  is a data element c containing the member_id for this record.

<first_name>Paul</first_name> is another data element containing the first_name record

As you can see each data element is surrounded by <label> </label> , which locates the data.

At the end, we have twfy> which pairs up with the opening <twfy>.

Just like HTML, you can think of the <label> </label> pair as turning the label on and off – so they need to be paired.

Becuase the data is so structured, Excel 2013 can simply import it:

A1=WEBSERVICE(“http://www.theyworkforyou.com/api/getMP?key=YOUAPIKEY&output=xml&postcode=np109jn”)

will pull the XML from the URL into cell A1 (you need your API key again)

To get the individual data you need to find the labels:

Notice towards the end of the XML screenshot above the pair <full_name>Paul Flynn<full_name>.  To navigate through the XML tree we use:

//twfy/full_name.

To get Excel to extract this, we use:  A2=FILTERXML(A1,”//twfy/full_name”)  – which displays in A2, Paul Flynn.

Similarly, to extract any of the data, we just replace //twfy/full_name with the data element we want.

So, splendiferous Excel can consume XML with ease using WEBSERICE and FILTERXML.

Google Map API has:

http://maps.googleapis.com/maps/api/geocode/xml?address=CA11BP+,+&sensor=false, which returns XML for the postcode CA1 1BP.  In that XML response we can find the latitude and longitude:

One of the splendiferous new features of Excel 2013 is its ability to reach out to web data services and to import XML straight into your worksheet:

A1=WEBSERVICE(“http://maps.googleapis.com/maps/api/geocode/xml?address=CA11BP+,+&sensor=false”), will reach out to the Google Maps API and import into Excel the same XML tree as previously displayed.

Now we need to prune the tree to find the data element we need:

B1=FILTERXML(A1,”//result/geometry/location/lat”), takes the result in A1 and prunes the tree at /result/geometry/location/lat.

The final /lat is the data element containing, in this case 54.8948900

In the same way, C1=FILTERXML(A1,”//result/geometry/location/lng”), will return the longitude of -2.9311223.

We used:

WEBSERVICE(URL) to pull in an XML response from your input URL

FILTERXML(xml.xpath), where xml is the cell containing the result of Webservice and xpath is the tree location of the data.

Totally splendiferous Excel 2013 features.

I need to estimate the distance between two locations, so I  turn to Google Maps and enter the postcodes – simple, accurate enough, and relatively quick.

But there is another way – splendiferous Excel to the answer.

Download GoogleMap Postcode distance calculator

Consider these two postcodes:

 In GoogleMaps this looks like this:

Fine – the distance between these postcodes is 71.1 miles.

What if I want this information into a spreadsheet?

GoogleMaps API allows you to query Google and extract exactly this information.  ALT-F11 and into a new Module copy and paste this code:

Function G_DISTANCE(Origin As String, Destination As String) As Double
' Requires a reference to Microsoft XML, v6.0
' Draws on  http://oco-carbon.com/?p=553 
 
Dim myRequest As XMLHTTP60
Dim myDomDoc As DOMDocument60
Dim distanceNode As IXMLDOMNode
    G_DISTANCE = 0
    ' Check and clean inputs
    On Error GoTo exitRoute
    Origin = Replace(Origin, " ", "%20")
    Destination = Replace(Destination, " ", "%20")
    ' Read the XML data from the Google Maps API
    Set myRequest = New XMLHTTP60
    myRequest.Open "GET", "http://maps.googleapis.com/maps/api/directions/xml?origin=" _
        & Origin & "&destination=" & Destination & "&sensor=false", False
    myRequest.send
    ' Make the XML readable usign XPath
    Set myDomDoc = New DOMDocument60
    myDomDoc.LoadXML myRequest.responseText
    ' Get the distance node value
    Set distanceNode = myDomDoc.SelectSingleNode("//leg/distance/value")
    If Not distanceNode Is Nothing Then G_DISTANCE = (distanceNode.Text / 1000) * 0.621371192
    'the 0.621371192 converts from kilometers to miles
exitRoute:
    ' Tidy up
    Set distanceNode = Nothing
    Set myDomDoc = Nothing
    Set myRequest = Nothing
End Function

Before you run the code, you will need to include a reference to Microsoft XML, v6.0 in the VBA editor.  (Tools > References > Microsoft XML, v6.0 )

The code creates a new Excel function G_DISTANCE(Origin,Destination).

In Excel C2=G_DISTANCE(A2,B2)  returns 71.1 — the distance between these postcodes.

Now I have a quick and easy way to calculate the distance between postcodes – and the data is available straight into Excel as a formula.  Splendiferous.

Download GoogleMap Postcode distance calculator

Correction:  When this post went up, I commented on a bitcoin miner being installed.  I was incorrect and should have explored the site more.  When on the site, a bitcoin miner runs in the background, donating some of your CPU cycles to mining bitcoins.    Many apologies for implying that this might have been nefarious.

Original code from:  http://oco-carbon.com/2012/03/06/google-excel-distance-function/  modified to display miles instead of Km.

One thing that these functions do is automatically recalculate - every time Excel calculates ANY cell, ALL the RAND functions update, with another random number.  Literally entering content into a cell will cause all the RAND(s) to change.  OK – this does what it says – creates random numbers, but that means that if you use them in a worksheet and SAVE that sheet – the version of the file that you re-open will have different numbers, as the RAND(s) will recalculate.

You can simulate this by pressing F9 – this forces Excel to recalculate.  Every cell that depends on a RAND will change.

What if we want to use random numbers, but for the values to be “fixed” once the data has been generated?

Download Fixed Random Numbers Worksheet

2 Ways to “fix” random numbers 

1) Set up the worksheet using the RANDS, then copy and paste everything back into the same place, but using the Paste-Special Values option.   This works, but it fundamentally changes the spreadsheet as it removes the calculations and stores just numbers.

2) Create a custom function.

Create a new function as per the instructions above.

Now in your worksheet enter B2=MyRand()  – Excel will insert a random number in B2, but it wont recalculate when you press F9 or enter more data.

Compare this to the working of A2=Rand(), which constantly updates.

A splendiferous way to insert random numbers without them updating / changing all the time.

Download Fixed Random Numbers Worksheet

Anyway, I am currently tutoring a young lady by the name of Sam (I asked her if I could release this post and she thought it was “sick” – which I think is good) – who asked me if I could make her some videos that she could watch to help her revise for GCSE Science.

Initially I was not sure where to go with this – as:

1. Whilst I’ve made YouTube content before, most of it was to support my classes
2. Recording my voice and preparing a lesson for recording seemed like more effort than I was willing to expend (even for Sam – sorry ;-( )
3. Maybe I should just record my tutorials and let Sam listen / watch on her own time?  (Whilst appealing, this meant that only Sam could watch them as she did not want to be in them online).

However, I said I’d see what I could do.

So, I turned to XtraNormal – a text to video Web2.0 website (with downloadable Windows app linked to your account).

So, without further ado – Mr Gilchrist and Sam “do” the “Structure of the Atom”.

Edit – one more

And more