[Lazarus] TAchart multiple reticules and vertical series alignment

[Alexander Klenin]

On Thu, Jun 3, 2010 at 18:02, Rick <rick at sloservers.com> wrote:

> The mailing list seems to be running really slow lately, almost as if
> it's only processing mail in nightly batches.

Are you sure it is not a problem on your side?
I do not seem to notice a large delays for mails in other threads.

> I really needed a stairstep series, and I found it much easier to
> implement in the line series rather than the area series.

Of course, if you only need lines, then TLineSeries is the way to go.

> (The bar graph series also does not respect linear offset transformation,
> by the way.)

Now that is an outright bug -- fixed in r25885

> I'll paste a unified diff so you can see what I did to the
> line series.  It's really quite basic and not particularly elegant, but it
> works great.  I didn't add reverse stairs since I don't need them, but
> it's only another three lines of code.

Thanks for the patch.
One problem with your code is that it does not take into account
other properties -- for example, it will not work for 3D-look series.
Also, TLineSeries already has a LineType property,
which can be used to encode stepped in addition to existing values.
Finally, there are two kinds of steps possible -- "X, then Y" and "Y, then X".
Stepped series were on my TODO list anyway, so I implemented them in r25889.
Also, I added a new linedemo to simplify testing of various property
combinations.
Please test.

> I'm having a little bit of trouble with my axis labels.  TAChart seems to
> only want to display even numbers on the horizontal axis, for example.
> Even when I use a custom source and set it to X values, it only shows
> the even numbers.  What am I missing?

I am not sure, seems to work for me.
Can you post a project demonstrating the problem?

> Another thing I noticed is that performance is pretty bad with 32 line
> series.  I'm not sure what the bottleneck is yet.  I'm guessing that it's
> floating-point math and thinking about trying a custom integer-based
> series.  Any thoughts on that?

How many points per serie do you have?

-- 
Alexander S. Klenin