WinForms Chart: Set Minimum Y-Axis Display Range
I have a Winforms chart in which I have temperature readings popping up and showing every second. I like the way the chart works automatically, handling the display of values, but I want to change one simple thing.
I want to increase the minimum displayable range of the y-axis, so it displays a range of 20. At the moment, it only displays around 5. I've tried a few things:
//(when new data arrives...)
//Does not work, I think because by default, Size is always NaN?
if (chart1.ChartAreas[0].AxisY.ScaleView.Size < 20)
{
chart1.ChartAreas[0].AxisY.ScaleView.Size = 20;
}
None of these functions work:
chart1.ChartAreas[0].AxisY.ScaleView.SmallScrollMinSize = 20;
chart1.ChartAreas[0].AxisY.ScaleView.SmallScrollSize = 20;
chart1.ChartAreas[0].AxisY.ScaleView.MinSize = 20;
chart1.ChartAreas[0].AxisY.Minimum //doesn't seem to have any effect
chart1.ChartAreas[0].AxisY.Maximum //doesn't seem to have any effect
I'm sure I missed something simple. I hope I don't care.
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The "Minimum Display Range" is not built into the MSChart control.
But you can easily fake it:
Add a dummy Series
that only contains two to make sure the display range is not below their y range ..:
int rangeMin = -10;
int rangeMax = 20;
sDummy = chart.Series.Add("dummy");
sDummy.Color = Color.Transparent;
sDummy.IsVisibleInLegend = false;
sDummy.ChartType = SeriesChartType.Point;
sDummy.Points.AddXY(0, rangeMin + 1);
sDummy.Points.AddXY(0, rangeMax - 1);
Place the y-axis as you wish:
Axis ay = chart.ChartAreas[0].AxisY;
ay.MajorGrid.Interval = 5;
And add one or more data Series
:
sData = chart.Series.Add("data");
sData.LegendText = "Temperature";
sData.ChartType = SeriesChartType.Line;
Now, when you add data points with a larger range , the y-axis will grow in its display range to accommodate them. And if you delete , then the larger dots will shrink back, but not below the range required for the dummy series ..:
Note that since it Chart
automatically adds some weak points , I decrease the range on both sides by 1
; with others Intervals
, etc. need other numbers.
Code to remove large values, btw:
var toRemove = sData.Points.Cast<DataPoint>()
.Where(x => x.YValues[0] >= rangeMax).ToList();
foreach (var dp in toRemove) sData.Points.Remove(dp);
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