### Running Totals in Excel

Excel does not have a running total feature or function built in.  All the examples I found on the web to do running totals included VBA code. Not that I have anything against VBA but I thought there should be a way to do running totals with built in worksheet functions.

Enter our one of our favorite functions: OFFSET().  But first, what is a running total?

A running total is when you have a list of Values and you want to total of the current Value with the Previous values.  Wikipedia states that a running total is "summation of a sequence of numbers which is updated each time a new number is added to the sequence, simply by adding the value of the new number to the running total."

The key to getting the SUM() correct is getting the Range correct.  For a given Range of Values, start with the First number and SUM() until you get to the current row.  You can do this by using the OFFSET() function and taking advantage of Excel's table features to get the column range.

[vb] OFFSET ( cell reference, rows, columns, [ height ], [ width ] ) [/vb]

In the above case the Running Total column's formula becomes:

[vb] =SUM( OFFSET( [Values], 0, 0, ROW() - ROW([Values]) + 1, 1 ) ) [/vb]

[Values] is the Column we want the running total for.

rows = 0 and columns = 0 because we want to start at the very first cell of [Values]

[width] = 1 because we want only the [Values] column

[height] = ROW() - ROW([Values]) + 1, this is the magic line.

To get the height we have to figure out our current Row number, subtract off the starting Row of [Values] then add 1.  ROW([Values]) gives us the starting row of the column and ROW() gives us the current row.  For example, if the Table starts on row 3 (headers are on row 3) then the column [Values] starts on row 4.  The height of the very first cell in [Values] is:

[vb] ROW() - ROW([Values]) + 1 = 4 - 4 + 1 = 1 [/vb]

The height of the 3rd cell in the [Values] column is:

[vb]ROW() - ROW([Values]) + 1 = 6 - 4 + 1 = 3 [/vb]

Offset Function in Excel

Running Total

### Json for jqGrid from ASP.Net MVC

jqGrid takes a specific format for its json (taken from jqGrid documentation): [js]{ total: "xxx",page: "yyy", records: "zzz", rows : [ {id:"1", cell:["cell11", "cell12", "cell13"]}, {id:"2", cell:["cell21", "cell22", "cell23"]}, ... ]}[/js] The tags mean the following: total - Total number of Pages. page - Current page Index. records - Total number of records in the rows group. rows - An array with the data plus an identifier. id - The unique row identifier, needs to be an int from what I have found. cell - An array of the data for the grid. The ASP.Net MVC framework has the JsonResult response type which we can use to populate the jqGrid. As an example I created a Person model and a method to return some data: [csharp] public class Person { public int ID { get; set; } public string Name { get; set; } public DateTime Birthday { get; set; } } public I

### Remote Controlled RoboTank

This is my version of the ever popular to build RoboTank. It uses an Arduino Mega 2560 with the AdaFruit motor shield and an XBee S1 to communicate to the DFRobot Gamepad. The sketch for the RoboTank makes use of the AFMotor.h to drive the motors and includes a serial parser to read and process the commands coming from the Gamepad. Robotank-Sketch.zip DFRobot Wireless Joystick

### Changing Typed DataSet Connection String

I was working on a WinForm app that connected to a MS Access database. Yeah, Access sucks but I didn't have a choice in the matter. The app itself is used to import a bunch of CSV files into the Access database. It is more of a utility program and it has going through several variations, from being a simple hand driven command line tool to being GUI driven. The command line version was all hand controlled. I had to go in and update configuration files to point to the CSV files and the MDB database. That got old fast so I decided to make a GUI version that would allow me to pick the MDB file and each of the CSV files to import. Picking and using the CSV files was easy, it was changing the connection string for the MDB that proved to be the hardest. I am using strongly typed datasets in VS2005. If you have ever worked with them you find out soon that the connection string gets saved with the project in the app.config file, even if it is a seperate DAL dll project. My guess is