Problems with plotting scattergraph

[maramckmc]

I am plotting with a scattergraph. I am reading data from a database plotting it with PlotXYAppend. However, on my graph, I also need to insert limit lines, which are also read from a database. The channel data (y-axis) is versed my time (x-axis) which continues to change. I need my limit lines to be seperate from channel plot and to remain on the graph as the time changes on the x-axis. I am very new to C# and using Measurement Studio.  I have code...

private void _Timer_Tick(object sender, EventArgs e)
        {
            double xValue = (double)NationalInstruments.DataConverter.Convert(DateTime.Now.TimeOfDay, typeof(double));
            double yValue = 0.0;
            //double lastXValue = 0.0;
            //double lastYValue = 0.0;

            //Plot1 
            if (_plot1 != null)
            {
                     foreach (Item item  in _plot1.Items)
                    {
                        yValue = _getter.GetChannel(ch.ID).CurrentValue();

                                               foreach (Table table  in _plot1.Tables)
                        {
                            _getter.GetTable(table.ID);
                            foreach (TableData ltd in lookup.TableData)
                            {

                                  //PLOTTING LIMIT LINES
                                double ltdXValue = ltd.X;
                                double ltdYValue = ltd.Y;
                                scatterPlot1.LineColor = Color.Red;
                                scatterPlot1.PointColor = Color.Pink;
                                scatterPlot1.PointStyle = PointStyle.SolidTriangleRight;
                                scatterPlot1.PlotXY(ltdXValue, ltdYValue);
                            }
                        }

                        //Plotting DATA
                        this.scatterPlot1.PointStyle = PointStyle.SolidDiamond;
                        this.scatterPlot1.PointColor = Color.Lime;
                        this.scatterPlot1.LineColor = Color.Yellow;
                        scatterPlot1.PlotXYAppend(xValue, yValue);
                    }
             

Also, for my time I am getting a number like 535330 (double xValue = (double)NationalInstruments.DataConverter.Convert(DateTime.Now.TimeOfDay, typeof(double))). How do I get the current timestamp? Thanks in Advance!

[nickb]

Hello,

One way to accomplish this would be to create a new plot object, and add it to the ScatterGraph's collection of plots.  Also, to get your X Axis to display the time instead of those large double values, you need to create a format string for the X Axis labels.  I have simplified your code a little bit, and these changes can be seen below:

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            // Assign a format string to the axis label
            scatterGraph1.XAxes[0].MajorDivisions.LabelFormat = new FormatString(FormatStringMode.DateTime, "hh:mm:ss");
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            Double limitVal = 6.5;
            Random rand = new Random();

            // Create new plot
            ScatterPlot limitPlot = new ScatterPlot();
           
            // Add new plot to Graph collection
            scatterGraph1.Plots.Add(limitPlot);

            //PLOTTING LIMIT LINES
            limitPlot.LineColor = Color.Red;
            limitPlot.PointColor = Color.Pink;
            limitPlot.PointStyle = PointStyle.SolidTriangleRight;
            limitPlot.PlotXY(DataConverter.Convert<Double>(DateTime.Now.TimeOfDay), limitVal);


            //Plotting DATA
            this.scatterPlot1.PointStyle = PointStyle.SolidDiamond;
            this.scatterPlot1.PointColor = Color.Lime;
            this.scatterPlot1.LineColor = Color.Yellow;
            scatterPlot1.PlotXYAppend(DataConverter.Convert<Double>(DateTime.Now.TimeOfDay), rand.NextDouble()*10);
        }
    }

 Let me know if I've misunderstood what you were asking for, or if I can help you with anything else!

NickB

National Instruments 

[maramckmc]

Thanks NickB,

I'm just in and will test the code, immediately. I'll let you know how it goes! THANKS!

[maramckmc]

Nick,

I think your suggestion will work, however, I'm still working on it.

Another thing, I have the correct time stamp when the plot is Channel vs. Time, but when I need it to be Channel vs. Channel, my x-axis is still a time stamp, when I need a range of numbers. Please help.

[maramckmc]

I have not a clue as to edit a recent post...Sorry...

Another question, how do I get my scattergraph to format automatically. For instance, what if my limit lines are at a point of 1 and 50,000 on the y-axis, and my other points are only at 86. And my database has it where it sets the range for the x and y-axes. For the points that are out of my range, how do I get to see the full graph with all the points plotted.