Add string value to object list at specific points

Question

I have this class for storing data read from an XML file:

public class cPoint
{
    public string point;
    public string time;
    public double xPoint;
    public double yPoint;
    public string csv;
}

I then have another class to scour the XML file and store data in List<cPoint> sorted = new List<cPoint>(); which is global:

...
if (measurementType == "Body")
{
    cPoint Point = new cPoint();
    Point.time = endTime;
    Point.point = location;
    Point.xPoint = Convert.ToDouble(xOffset);
    Point.yPoint = Convert.ToDouble(yOffset);
    sorted.Sort((x, y) => x.point.CompareTo(y.point));                                                                
    csvString = endTime + "," + location + "," + xOffset + "," + yOffset;
    Point.csv = csvString;
    sorted.Add(Point);                 
}

and finally I use this code in my main to sort through the distinct names in sorted and calculate the standard deviation of the associated xPoint and yPoint:

List<string> PointNames = sorted.Select(x => x.point).Distinct().ToList();
foreach (var name in PointNames)
{

    // Get all Values Where the name is equal to the name in List; Select all xPoint Values
    double[] x_array = sorted.Where(n => n.point == name).Select(x => x.xPoint).ToArray();
    string StdDevX = Convert.ToString(Statistics.StandardDeviation(x_array));

    // Get all Values Where the name is equal to the name in List; Select all yPoint Values
    double[] y_array = sorted.Where(n => n.point == name).Select(x => x.yPoint).ToArray();
    string StdDevY = Convert.ToString(Statistics.StandardDeviation(y_array));

    //Something along these lines:
    //sorted.csv += StdDevX "," + StdDevY; 
}

List<string> CSV = sorted.Select(x => x.csv).ToList();
WriteToFile(Title);
WriteToFile(CSV);

What I would like to do is add a string of StdDevX + "," + StdDevY to each sorted.csv with a distinct name. As you can see at the bottom of my code, I'm writing sorted.csv to a an excel file (as a comma separated value). Here is my expected output to illustrate what I need.

Any help would be great guys

slawekwin · Accepted Answer · 2016-09-01 06:42:27Z

2

Try this:

sorted.Last(n => n.point == name).csv += StdDevX "," + StdDevY;

edited Sep 1, 2016 at 6:42

slawekwin

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answered Aug 31, 2016 at 8:00

owczarek

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2 Comments

ChrisD91 Over a year ago

Hmm, I'm getting the error cPoint does not contain a definition for "ForEach"? Perhaps I'm doing something stupid..

owczarek Over a year ago

Right, my bad. Should be: sorted.Last(n => n.point == name).csv += StdDevX "," + StdDevY;

DeveloperExceptionError · Accepted Answer · 2016-08-31 08:42:38Z

1

Another way of handling this:

// Equal to your distinct, but returns the point objects instead.
List<cPoint> lstPoints = sorted
    .GroupBy(x => x.point)
    .Select(g => g.First())
    .ToList();

// Loop through all points with a distinct .point property
foreach (cPoint point in lstPoints)
{
    // Get all Values Where the name is equal to the point.name in List; Select all xPoint Values
    double[] x_array = sorted.Where(n => n.point == point.name).Select(x => x.xPoint).ToArray();
    string StdDevX = Convert.ToString(Statistics.StandardDeviation(x_array));

    // Get all Values Where the name is equal to the point.name in List; Select all yPoint Values
    double[] y_array = sorted.Where(n => n.point == point.name).Select(x => x.yPoint).ToArray();
    string StdDevY = Convert.ToString(Statistics.StandardDeviation(y_array));

    // Edit the existing item of the list
    point.csv += "," + StdDevX + "," + StdDevY;
}

List<string> CSV = sorted.Select(x => x.csv).ToList();
WriteToFile(Title);
WriteToFile(CSV);

edited Aug 31, 2016 at 8:42

answered Aug 31, 2016 at 8:06

DeveloperExceptionError

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4 Comments

ChrisD91 Over a year ago

I tried that initially but it gave me a few errors only assignment, call, inc, dec and expressions can be a statement and string does not contain a definition for "csv". Unless I was applying the statement incorrectly

DeveloperExceptionError Over a year ago

@ChristopherDyer I see, you are using a string list. Missed that on my first read. Updated my answer.

ChrisD91 Over a year ago

Ah, I see what I did wrong now. Your solution is probably the most elegant but the accepted answer is a quick solution for the code provided. It's a shame I can't accept both.

DeveloperExceptionError Over a year ago

@ChristopherDyer I even thought about deleting it after I had seen the existing answer and your commend. Good thing I did update it. Glad I could help you.

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