VB 2008
.NET FRAMEWORK 3.5
MSCHART - FASTLINE CHART TYPE
Is it possible to have an MS Chart control contain 20,000 data points, but only show the last 100?
I know that I can select the last 100 from my datatable and use it as a datasource.
Chart1.DataSource = cMs2.dsData.Tables("readings").Select(wFilter, wSort).Take(100)
That's not what I want.
I know that I can populate an array or collection with the last 100 data points and use it as a data source.
Chart1.Series("readings").Points.DataBindXY(colCtr, colReadings)
That's not what I want.
I need to do 1 of 2 things:
Manually add data points and be able to show only the last 100 or last 1000 of them that just came in. This must be done without re-populating the chart. Just show a portion of the complete set of data points.
wSample = wSample + 1
Chart1.Series("readings").Points.AddXY(wSample, wReading)
Chart1.Series("readings").SHOWONLYTHELAST100DATAPOINTSWITHOUTCLEARING
Initialize a chart with a certain number of the total readings with a databind, then manually add new data points one at a time while removing the oldest data point. For example, initialize the chart with 100 data points, then add a new data point, remove the first data point, getting us back to 100. (I'm successfully doing this one, except the chart doesn't behave like I expect. The chart grows, remaining blank/empty where the 'removed' data points were. I do chart.update but it doesn't refresh it.) Note that I am allowed to take more time to initialize the chart (clear/populate), I don't have that time to do it as each new data point comes in.
wSample = wSample + 1
Chart1.Series("readings").Points.AddXY(wSample, wReading)
If Chart1.Series("readings").Points.Count > 100 Then
Chart1.Series("readings").Points.RemoveAt(0)
Chart1.Update()
End If
NOTE: Doing a process that causes me to have to clear and rebind the data to handle the addition of a single data point causes me problems because it takes too long. I'm just looking for the quickest, most efficient way to handle this. Thank you for taking the time to read this...!
You can manually set the Minimum and Maximum values of each axis by modifying the .Minimum and .Maximum values of the axes like
Chart1.ChartAreas(0).AxisX.Minimum = 100 'Example value
Chart1.ChartAreas(0).AxisX.Minimum = 200 'Example value
As discussed in the comments to your question you can either use your method #2 (add datapoint and delete datapoint index 0 and then select the new minimum and maximum X-Value from the series with LinQ:
Chart1.ChartAreas(0).AxisX.Minimum = (From p As DataVisualization.Charting.DataPoint In Chart1.Series(0).Points Select p.XValue).Min
Chart1.ChartAreas(0).AxisX.Maximum = (From p As DataVisualization.Charting.DataPoint In Chart1.Series(0).Points Select p.XValue).Max
or you can, as you have now done, just set the minimum value to a X-value some points before the last point.
Related
I have an automated pareto chart working well in Excel.
I want to change it to check if points in the cumulative percentage series have a value of less than 80% and colour the same number point in the count series if this is the case.
Tried this; doesn't throw any errors but also doesn't work.
I think it should be iterating through a list of values, checking if they are <80 then updating the point at the corresponding i in the count series.
Set percVals = paretoChart.Chart.SeriesCollection(percentSeries).Values
For Each i in percVals
If percVals(i) = <80 Then
With paretoChart.Chart.SeriesCollection(countSeries).Points(i)
.Format.Fill.ForeColor.RGB = RGB(0,0,225)
.Format.Line.ForeColor.RGB = RGB(0,0,225)
End With
End If
Next i
The "paretoChart" variable is set earlier in the code and is working fine throughout.
I've tried without the 'with' statement. No difference.
There is a similar question comparing the two values across series, but I don't think I can adapt that to work here. Any ideas appreciated!
I have a chart with multiple line series (let's say 10). Each line series is comprised of about 2,000 points. Does anyone know why it takes MINUTES for the chart to render? Is this simply how poorly this control behaves?
I've found that removing the points increases performance 10-fold. However; I want to see the data points. See below how I have removed the data points...
Style pointStyle = new Style(typeof(LineDataPoint));
pointStyle.TargetType = typeof(System.Windows.Controls.DataVisualization.Charting.DataPoint);
pointStyle.Setters.Add(new Setter(TemplateProperty, null));
pointStyle.Setters.Add(new Setter(LineDataPoint.BackgroundProperty, model.LineColor));
series.DataPointStyle = pointStyle;
The line where I set the TemplateProperty to null is what made the chart perform so quickly.
Any alternatives which still display the data points?
See image for what I have going on
So the red column will at some point, which is different every day, change from 20 to 50. The start cell up top uses that lookup formula to find when this is. So for this example it is 10/11/16 14:37. I want to graph the green and blue columns, starting at that cell time and ending at the end time (which is just a max() of the times to get the end time).
I've looked into offset and name manager but I am really confused on those. Either using VBA or something else to change the graph (on a different sheet) to start at whatever that start time is would be awesome.
You can try the following:
In the column AL set, in each cell, the value to be defined by the following formula
AL1 = IF(AI1<50,0,1)
AL2 and following = IF(AL1=1,1,IF(AI2<50,0,1))
Then define each AM to be AL*AK, and plot AM.
Using Excel, lets say I have a validation list made of 5 values like this one :
Patate
Tomate
Courgette
Concombre
Patate
In a cell containing a drop down list made of these 5 value, I select the fifth value : "Patate".
I want to get in VBA that this cell contains the 5th value of my validation list. Something like :
x = Cell.Validation.GetIDValueSelected
x = 5
I can't use Vertical search because I might have 2 or even more time the same value in my list (too long to explain why).
This list is also dynamics (depending of another sheets) so it doesn't always contains 5 values.
I hope I made it clear for everyone to understand my needs but I will be glad to add more information if needed.
Thank you for your time.
Sadly, once you have used DV to fill a cell with junk, there is no way to tell which piece of junk you picked:
You would have to pad each piece of junk with a different number of blanks.
I'm trying to find the Min/Max value of a textbox that has 1 variable and display it to the user, so the variable changes everytime the button is clicked. How would I find the maximum value of something that is constantly changing? The trick is that I can NOT use if statements or case statements. I'm totally at a loss here.
Ok, the things that limit you.
One variable
no if/case statements
The lesson seems to revolve around using Math.Max().
Math.Max(), as we can see on MSDN returns
the larger of two 32-bit signed integers.
The one variable we are going to use needs to exist outside of the button's click event. So, just make it a class variable.
This variable will essentially store the largest value. Math.Max() returns the largest of two values... see what I am getting at here? You can pass the current largest variable as a parameter to Math.Max() without any issues.
Example:
Dim max As Integer
max = Math.Max(1, 100)
'max would be 100
max = Math.Max(max, 10)
'max would be 100
max = Math.Max(max, 1000)
'max would be 1000