I'd like to draw a custom 2nd axis that's tied to data but .

[dunion]

this one woud scale differently. It has to be tied to the existing data so that the zooms and such work.

For example let's say I have 50 points and the first axis labels them from 800-1000 in steps of 4 (horizontal axes with ticks). For example, let's say the default ticks are going to be every 5 points.

I want another axes, tied to the same data, that is also horizontal, that labels the same points differently, for example from 100-250 in steps of 3 and I want a tick every 3 points along this axes. I might have this float a bit above or below where the other horizontal axes is (say, for example, +5% up on the drawing area (above) the other axis.

I don't want the 'first' one to try to 'rescale'; that is the start and end are 'the same', this is just two representations of the 'same data' (for example different units, etc.).

If I custom draw, then I have to handle all the zoom and redraw code manually (which I can do) but I was wondering if there is a default way to do this.

[dunion]

I added a new line with a 'y' value of 0 for each of the points in the first line and an 'x' value associated with the new range I want. Then I made a custom horizontal axis for that line and added it to the chart. Looks really ugly right now but that's all a matter of moving stuff around.

Steema.TeeChart.Axis axis1 = new Steema.TeeChart.Axis(false, false, tChart1.Chart);
tChart1.Axes.Custom.Add(axis1);
line2.CustomHorizAxis = axis1;
axis1.StartPosition = 0;
axis1.EndPosition = 100;
axis1.Automatic = false;

[Sandra]

Hi dunion,

Custom axes don't support zoom. You have to do that manually as told here.

Also, for add extra axes you can see Tutorial4 for NET, on how to add a new axis, and changing some properties of axes.

If you have any problems, please tell exactly we must do, because we can reproduce here your issue.

[dunion]

That didn't do quite what I want. What I want is pretty simple.
Two axes for the same data with different units. Say the data is a bunch of values.
The 'bottom axes' can be 'automatic' and track the values used for the curve data.
The 'top axes' needs to be different non-related units but still there is a one-to-one
correspondence that I know.

100 200 300 400 500 ... etc.
---------+-----+----+-----+----+----------------------
100

80

70

60

50 (some curve here)
------+-----+----+---+---+---+---+------------------
5 10 15 20 30 40 50...


What I've tried if from your last reply and from the sample, didn't quite do what I was looking for. Do you have a sample of this?

Thanks.

[Yeray]

Hi dunion,

If I understand well, you should assign both top and bottom axis to your series and then modify one of the axis labels at OnGetAxisLabel event knowing the relation. For example with a relation 1x100:

Code: Select all

        public Form1()
        {
            InitializeComponent();
            InitializeChart();
        }

        private void InitializeChart()
        {
            chartController1.Chart = tChart1;

            tChart1.Aspect.View3D = false;
            tChart1.Legend.Visible = false;

            Line line1 = new Line(tChart1.Chart);
            line1.FillSampleValues(25);

            line1.HorizAxis = HorizontalAxis.Both;

            tChart1.GetAxisLabel += new GetAxisLabelEventHandler(tChart1_GetAxisLabel);

        }

        void tChart1_GetAxisLabel(object sender, GetAxisLabelEventArgs e)
        {
            if (sender == tChart1.Axes.Top)
            {
                e.LabelText = (Convert.ToDouble(e.LabelText) * 100).ToString();
            }
        }

[dunion]

Is there an other way to do this?
I don't always want to show this second axis: it depends on what button the user used to start drawing on this chart as I use it for a lot of different drawing scenarios, so it shouldn't be a general event handler.

One option is to add and remove the event handler all the time - which could become a threading challenge, or have some locked flag for mode.

Also my code has a couple of tcharts, and the functions I use pass in a pointer to a tchart object and do stuff with one - so I'd rather not hook up an event handler to a specific chart by name if I can avoid it. Otherwise I'd have to have handlers for each of the charts and a bunch of locked mode flags to check for every axis label, and that could effect performance (I'm taking live data for this chart).

[dunion]

I did try that suggested method. I explicitly constructed the handler for my chart and put the suggested code, the only other thing I put was a check to verify (in the tChart2_GetAxisLabel) what 'tab' of a tab set I was on. Then after putting a break point in the debugger on the e.LabelText = ...
inside the
if (sender == tChart2.Axes.Top) {

I never hit this breakpoint and my graph turns into a white screen with a big red 'X' in the middle.

[dunion]

I should also mention that if I just set
refLine.HorizAxis = Steema.TeeChart.Styles.HorizontalAxis.Both;
I never see an axis on top.

refLine is a 'FastLine'.

I think there is one bug fix release since I updated this version. If this is a bug that can be solved by an update, either to the latest patch version or the 2009 version also let me know.

[Narcís]

Hi dunion,

In that case I think the easiest option is passing the labels you want at the top axis to the Add method as shown in the code snippet below and then set the Labels.Style you want for each value.

Code: Select all

			Steema.TeeChart.Styles.FastLine fastLine1 = new Steema.TeeChart.Styles.FastLine(tChart1.Chart);

			Random y = new Random();

			for (int i = 0; i < 10; i++)
			{
				double tmp = y.Next();
				fastLine1.Add(tmp, "point " + i.ToString());
			}

			fastLine1.HorizAxis = Steema.TeeChart.Styles.HorizontalAxis.Both;
			tChart1.Axes.Top.Visible = true;
			tChart1.Axes.Top.Labels.Style = Steema.TeeChart.AxisLabelStyle.Text;
			tChart1.Axes.Bottom.Labels.Style = Steema.TeeChart.AxisLabelStyle.Value;

[dunion]

Thanks.
I tried this but still don't see any top axis. I did some debugging, while stepping through I get four kinds of cases for the events for the top axis. In this case I only had one line on the chart but usually I have at least two different lines, at least one a 'line' and one a 'fastline', on this tChart object instance.

tChart2_GetAxisLabel() {
if (sender == tChart2.Axes.Top) {
...
One has e.LabelText = "";
One has e.LabelText = "0".
Another has a single value that looks like my x-axis values
Another has a comma-separated value-pair that has an integer and maybe my y-axis values.

Should I try to set e.LabelText back to a string[] array like 'point number, text' rather than just a single text value?

[Yeray]

Hi dunion,

Note that the code that Narcís posted above doesn't use OnGetAxisLabels nor any other event. Could you try that code in a simple new application to see if the axes are shown in a similar way than what you expected?

[dunion]

I tried that first and didn't see anything on the top of the chart, that's when I thought he might also be expecting me to do stuff with 'ongetaxis'. No luck there either.

[Narcís]

Hi dunion,

Thanks for the info. Can you please attach a simple example project we can run "as-is" to reproduce the problem here and let us know the exact TeeChart version you are using?

Thanks in advance.

[dunion]

I haven't had time to create a separate test project, and today is pretty straight out, I'll try to over the next couple of days.
I have a fairly simple project in terms of teechart, at least I thought so. I have two tabs each with a tchart, and I add or remove lines from whichever tab is currently 'visible'

So i could add a line to one chart, view the other tab, add a line to it, and go back to the 1st chart and clear or add another line to it.

I have general data (that may be live/continuous on one line and a 'static' set of data on another comparison line).

I have an axis on the bottom that is 'automatic' based on the x-values, i want another 'x-value' axis on top with a different set of numbers that i can compute via a formula and lookup array based on the x-value axis

Teechart version is
3.5.3425.20245

The chart is otherwise fairly 'generic', 2d, and using one of the built-in themes (and the user can change that theme but that doesn't effect the behavior in any way).

I tried the text as suggested and didn't see the top line. I tried creating a new line with a bright color and putting it on top, I can do that, and for a while I was trying to use a new line on top (a new fastline) with it's only axis on top, and values based on teh 2nd set I wanted to use - then make the line itself 'transparent' so I didn't see it.