TChart - DateTime on XAxis - setting question(s)
lazarus / 55-TAChart

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vx-rexx · 2011-12-01 21:37

Hello,

1. I have a bar-chart with Source: DateTimeIntervalChartSource and
Style: smsLabel.
Steps dtsDay, dtsMonth and dtsYear set True.
I have the problem that if I get very few Data-Point's (maybe 3; I
have only one Data-Point at a Day ) no Marks displayed.
If I set dtsHour True then Marks with hour are displayed, but I need
only Day and Month, perhaps Year (if it is changed).
My chart is default Height/Width 687/805. If 6 Data-Points on chart
Marks on XAxis are displayed (if size of window/chart is default) .
The Size of program-window is changeable. Now, if I change the size of
window (and so also the size of chart) sometime no Marks at Bottom.
Where can I set that always Marks at XAxis are displayed?

2. Line-chart, also with Source: DateTimeIntervalChartSource and
Style: smsLabel.
Steps dtsDay, dtsMonth, dtsYear, dtsHour, dtsMin and dtsSecond set
True.
I need 2 Lines on Bottom-Axis:
  First line 'hh:mm:ss'
  second line 'dd.mm.'
example:
22:15:20
 01.12.

How can I get this?

I hope you can help me.

Windows: Lazarus 0.9.31 SVN 33083, FPC 2.5.1
Linux: Lazarus 0.9.31 Source: 27.11.2011, FPC 2.4.4

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Ask · 2011-12-02 08:48

QuoteI have the problem that if I get very few Data-Point's (maybe 3;
I have only one Data-Point at a Day ) no Marks displayed.
You have several options:
1) You can adjust DateTimeIntervalChartSource.Params (probably
MinLength and MaxLength), see http://wiki.lazarus.freepascal.org/TACha
rt_documentation#Axis_intervals

2) You can enable all Steps -- this will ensure that *some* interval
will be displayed at
most zoom levels, although perhaps not in the units you prefer.

3) If you do NOT need to zoom your chart, you can use a simple
ListChartSource
with pre-determined marks.

I can offer more specific advice if you would upload a sample code.
I have seen your post on the German forum, but I am not registered
there
and thus unable to download attachments.

QuoteI need 2 Lines on Bottom-Axis
Set DateTimeFormat property to include end-of-line sequence.
TAChart should automatically break labels containing end-of-line into
multiple lines
(see "labels" demo for an example).

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vx-rexx · 2011-12-02 20:27

Thank's Ask.

I have tryed it with
Code: [Select]DateTimeIntervalChartSource1.DateTimeFormat:='hh:mm:ss'+
#13+'DD.MM.';but
Code: [Select]DateTimeIntervalChartSource1.DateTimeFormat:='hh:mm:ss'+
#13#10+'DD.MM.';work.
(MessageDlg('String_1'+#13+'String_2') work's fine so. I thought I
only need #13.  )

The Attachment is a little example that demonstrate my problem.
Have you more then 2 Data-Point's created (Add-Button), Marks are
displayed.
Now, for example, you have 3 Data-Point's created, please change the
size (width) of window. At some point there is no Mark.
My first Monitor has 1680x1050 and second Monitor 1280x1024
Resolution. I can (and use this from time to time) change size of
window over the full width (2704). In  this example I need 7 Data-
Point's or more and Marks are displayed.

(System for this example: Windows 7, Lazarus 0.9.31 SVN 33083, FPC
2.5.1)