Logarithmic scaling

[mc-electronic]

Hi all,

I run TeeChart Pro V 8.06 on Delphi 7. I have an application, that requires logarithmic scaling on the Y-Axis. As long as I use scalings like Minimum = 0 and Maximum = 100 it works. However, I need scaling in very small numbers, e.g. Minimum := 0.000001; Maxiumum := 0.001; I get no Y-Axis labels at all. The Series is drawing all right, but there are no labels.

What am I missing?

Thank you! Michael

[mc-electronic]

Hello all,

I am a bit further, I get some scaling now. However, as soon as I move the chart with the right mouse button, the scaling and the graphic are gone. I have prepared a sample project with some manual data. What am I missing?

Thank you, Michael

[Narcís]

Hi Michael,

What about setting bottom axis Increment? For example:

Code: Select all

  Chart1.Axes.Left.Increment:=0.0001;

If scrolling logarithmic series out of axis range you may not see any label. Unzooming the chart will display labels again.

[mc-electronic]

Hello Narcis,

I tried the increments you suggested (on bottom axis and on Left axis - you suggested both). However, my main problem now is the scolling (and zooming). Have a look at my sample and try to move (scroll) the chart with the right mouse-button - the graph is not simply moving, but gets deformed or vanishes. You can scroll very carefully a littlebit, if you click as close as possible to the bottom axis into the chart.
A linear chart moves nice around, but the logarithmic chart behaves 'unexpected'.

Best regards, Michael

[Narcís]

Hi Michael,

Yes, I'm afraid this is just because of logarithmic axis scaling. Scroll and zoom use axes scales for their calculations instead of screen pixels.