Automating Repetitive Tasks

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Three week ago I visited the Newton Excel Bach web site where I spotted the Dynamically Defined Dancing Pendulums NewtonExcelBach.

Having noticed that Doug had done a nice animation in Strand7 (a Finite Element Analysis program) Strand7, I thought “I can do that in Excel” and so I did.

This post will not go through the logic of constructing and animating the pendulums in Excel as I have described that over at Excelhero.com and readers who are interested are encouraged to visit there and explore the techniques used.

During the Pendulum project I came across two sub-projects which I felt are worthy of a post here at Chandoo.org as they are a great demonstration of some basic VBA techniques as well as demonstrating the ability of VBA to quickly simplify repetitive tasks.

Sample files are attached for Excel 97-2003 and Excel 2007/10 users to follow through the examples.

 

PENDULUM SIDE PROJECTS

The Pendulum project consists of 16 Pendulums. Each Pendulum requires 4 Named Formulas, meaning that the projects needs 64 Named Formulas for the 16 Pendulum, as well as adding 16 Series to the chart.

Huis_Excel_Dancing_Pendulums

(The above animated GIF is a very poor representation of the smooth scrolling achieved in the Excel animation)

I thought it would be a great idea to see if these jobs could be automated and hopefully save some time during the process.

The result was 2 simple VBA routines which will be described below:

 

NAMED FORMULAS

Each Pendulum in the project was based around 4 Named Formulas

Named Formula for each Pendulum

p1Len =’1′!$B$9                                                   The Length is stored on the worksheet.

p1o =OMax*SIN(SQRT(g/p1Len)*t)      Current angular position of Pendulum 1 at time t

p1x =p1Len*SIN(p1o)*{0;1}                      Current orthogonal X position of Pendulum 1 at time t

p1y =-p1Len*COS(p1o)*{0;1}                   Current orthogonal Y position of Pendulum 1 at time t

 

The only difference between the formulas for Pendulum 1 and Pendulum 2 etc is the replacement of the names of p1 with p2 in the various Named Formulas and of the associated formulas.

On a worksheet Named Formulas a number of formulas were written which display the Named Formulas as required above. Then a small VBA routine was written which loads the Named Formulas.

How

On the Named Formulas worksheet, I have added two columns of formulas for the various Named Formulas required.

For the Pendulum Length Named Formulas

For the Pendulum Angular Position Named Formulas

For the Pendulum X Position Named Formulas

For the Pendulum Y Position Named Formulas

When the formula above are copied down they adjust for the various pendulums numbered 1 to 16 based on the row numbers.

I then setup a VBA routine, Load_Named_Ranges, shown below which loads the Named Formulas.

To Use

Select some or all of the required Named Formulas from the Name Column. That is the code will only load the Selected Named Formulas, allowing the user to load 1 or 2 Named Formulas, for testing purposes, or all the Named Formulas if you choose.

Then Execute the Load_Named_Ranges subroutine either using the Big Red Button or directly within the VBA Editor.

The following will load Named Formulas p3Len to p7Len.

The Load_Named_Ranges subroutine is shown below:

Sub Load_Named_Ranges()

Dim c As Range

For Each c In Selection

ActiveWorkbook.Names.Add Name:=c.Text, RefersTo:=c.Offset(, 1).Text

Next

End Sub

What does the code do?

The code:

1. Defines the start and name of the subroutine,

Sub Load_Named_Ranges()

2. Defines a variable c as a Range object,

Dim c As Range

3. It then loops through each cell in the selection and assigns it to the variable ‘c’;

For Each c In Selection

4. It then adds a new Named Formula,extracting the Name from the Text Value of ‘c’ and extracts the formula from the cell directly to the right of cell ‘c’;

ActiveWorkbook.Names.Add Name:=c.Text, RefersTo:=c.Offset(, 1).Text

The Name and Formula (RefersTo) both use the Text of the cell, which is what is displayed.

5. It then loops through each cell in the selection until it has done them all;

Next

6. Defines the end of the subroutine;

End Sub

Lets Test It

To test the subroutine we will first delete all the Named Formulas beginning with “p”

Goto the Formula Ribbon Bar and select Name Manager

Select all the Named Formulas that begin with “P” and press the delete button

Accept any warnings

Try and Run the Pendulum’s

Nothing happens as there are no formulas

Ensure the Pendulum are turned off, as the code is still running behind the scenes.

Now Goto the Named Formulas Page

Select all the Named Formula Names in Name Column; B3:B66

Click the Load Named Formulas, button

Go back to Page 1 and try and run the Pendulums now.

 

ADD CHART SERIES

The second sub-project was the addition of 16 Chart series to the Chart, 1 for each Pendulum.

Using the logic of the Named Formulas VBA code above, the 16 Chart Series Names, X Values and Y values were developed using formulas on the Add Cht Series worksheet and then loading into a chart using a simple VBA routine.

The Add_Cht_Series subroutine is in the Add Cht Series sheet object in the VBA editor.

How

On the Add Cht Series worksheet, I have added three columns of formulas for the various Named Formulas required.

For the Pendulum Name, X Range and Y Range.

When these formulas are copied down they adjust for the various pendulums numbered 1 to 16.

I have then setup a VBA routine, Add_Chart_Series, shown below which loads the Named Formulas.

To use Select some or all of the required Chart Series from the Pendulum Name column.

Then Execute the Add_Chart_Series subroutine using the big red button.

The Add_Chart_Series subroutine is shown below:

Sub Add_Cht_Series()

Dim sNumb As Integer

Dim c As Range

Worksheets(“1”).ChartObjects(“Chart 5”).Activate

For Each c In Worksheets(“Add Cht Series”).Range(“B19:b20”)

sNumb = ActiveChart.SeriesCollection.Count + 1

ActiveChart.SeriesCollection.NewSeries

ActiveChart.SeriesCollection(sNumb).Name = c.Text

ActiveChart.SeriesCollection(sNumb).XValues = c.Offset(, 1).Text

ActiveChart.SeriesCollection(sNumb).Values = c.Offset(, 2).Text

Next

End Sub

What does the code do?

The code:

1. Defines the start and name of the subroutine,

Sub Add_Cht_Series()

2. Defines a variable sNumb as an integer,  and a variable c as a Range object

Dim sNumb As Integer

Dim c As Range

3. It then activates the Chart containing the pendulum

Worksheets(“1”).ChartObjects(“Chart 5”).Activate

4. It then loops through each cell in the Range defined by the Range, in this case B19:B20 and assigns it to the variable ‘c’;  You can adjust the Range to suit.

For Each c In Worksheets(“Add Cht Series”).Range(“B19:B20”)

5. It then counts how many existing series are in the chart and sets the next Series Number sNumb to that value + 1.

sNumb = ActiveChart.SeriesCollection.Count + 1

6. The next 4 lines add a new series to the chart and setup the new series Name, X Value and Y Values. The Name, X Value and Y Values are retrieved from the Text of the cell c and the adjacent two cells using a Range Offset modifier

ActiveChart.SeriesCollection.NewSeries

ActiveChart.SeriesCollection(sNumb).Name = c.Text

ActiveChart.SeriesCollection(sNumb).XValues = c.Offset(, 1).Text

ActiveChart.SeriesCollection(sNumb).Values = c.Offset(, 2).Text

7. It then loops through each cell in the selection until it has done them all;

Next

8. Define the end of the subroutine;

End Sub

Lets Test It

To test the subroutine we will first delete a few of the Chart Series

Select the Chart

Select two Pendulums noting the series Number of the Bobs eg: 9 & 10

Goto the Add Chart Series Worksheet

Note the Range Corresponding to the 2 missing Pendulum B11:B12

Goto the VBA Editor

Adjust the Line

For Each c In Worksheets(“Add Cht Series”).Range(“B11:B12”)

With your cursor in the Subroutine press F5 once only

Go back to Page 1 and you should now have 2 New Pendulum

Run the Pendulums now.

You will have to manually set the shape of the Bobs to a Circle and size 15 and re-arrange the order of the series to ensure they are in order, but you can practice that manually.

SUMMARY

The post has shown how using some very simple VBA and a bit of lateral thinking to put together some simple tools to simplify 2 common and repetitive tasks.

In the Named Formulas case, the code took less than 2 minutes for me to write and then another 5 minutes to do the formulas for the Named Formulas. I didn’t try but I am sure it would have taken a good 20+ minutes to enter 64 Named Formulas.

Writing this post took much longer than doing the whole Pendulum Project.

Two examples during my working career, where VBA code has been used to save massive amounts of time and money:

In the first case I wrote some code to combine data from several hundred workbooks with varying numbers of sheets up to 30 and differing quantities of data on each sheet, a task that could have taken weeks manually with the included opportunity for errors to be introduced, into a subroutine which took 30 minutes to run and gave a printout of the results including what files, sheets and rows of data were included in the import.

In a second case a Number of Workbooks, a Word template and some VBA code was used to replace a person whose sole job was to manage that data. This job saved the company $50k+ per annum and the task was given to a clerical person who could now do the task in their spare time.

LINKS

Huis Excel Hero Pendulum: http://www.excelhero.com/blog/

Pendulum Physics: http://hyperphysics.phy-astr.gsu.edu/hbase/pend.html

Newton Excel Bach: http://newtonexcelbach.wordpress.com/2011/05/25/dancing-pendulums-2/

 

What could your simplify by using automation within Excel ?

What could you simplify or speedup using Excel automation?

Let us know in the comments below: