Chart with 20,000 Data Points

Hi!

First post for me -- but I've been using Quattro since the late 1980's. 

I am trying to create a chart with nearly 20,000 points on the x-axis.
(More specifically, I am charting a 12 month moving mean of high
temperatures for a single weather station for Aug 1948 through Dec 2001.)

1. I am getting *frequent* gpf's. I've crashed about 20 times. I do
something; crash; I try it again another way; no crash; save; loop.

2. I *cannot* get the x-axis to look halfway decent.
   2a. "Skip Labels" maxes out at 99 labels skipped. I need to skip
365.
   2b. So I use automatic skip. This gives no label on the right edge.
   2c. Grids do not line up with the auto-skipped labels.
   2d. Grids do to make it to the right edge of the graph.


Any help appreciated -- even the information that Q12 becomes unstable when
you use 20,000 data points (duh!).


Jim Hargan

Jim Hargan wrote:
> I am trying to create a chart with nearly 20,000 points on the x-axis.
> (More specifically, I am charting a 12 month moving mean of high
> temperatures for a single weather station for Aug 1948 through Dec 2001.)

Even if you would experience NO problems of any kind, I would create a separate

time series of monthly averages and plot that instead, because the visual 
significance of daily fluctuations is utterly drowned out by monthly trends when

dealing with time spans of several decades (in this case half a century).  Even

though it may be an impressive feat by the software to plot 20,000 data points,

I don't think our eyes and brains are able take meaningful advantage of such 
overwhelming informational content.

> 2. I *cannot* get the x-axis to look halfway decent.
>    2a. "Skip Labels" maxes out at 99 labels skipped. I need to
skip 365.
>    2b. So I use automatic skip. This gives no label on the right edge.
>    2c. Grids do not line up with the auto-skipped labels.
>    2d. Grids do to make it to the right edge of the graph.

You have far better control over the x-axis if you use a scatter plot type chart

(instead of a line chart), both in terms of controlling primary and secondary 
intervals and in terms of formatting the axis labels.

Over such a time span it's better to skip 365.25 days, otherwise you'll incur a

gradually accumulating drift, which among other things would cause you problems

with your annual labels:  the beginning of each year would be out of sync by 
almost half a month after 50 years.

(I can only give generic advice here, since I don't have v12 -- charting is one

of the reasons why I've stayed with v8.)

Cheers,
Uli

Uli:
> (I can only give generic advice here, since I don't have v12 -- charting is
one 
> of the reasons why I've stayed with v8.

I think that this applies a) to the chart type that Uli suggests and b) to QP12.

The issue has now been improved - I do not remember at which stage the
improvement 
was applied.

This is from a post in the Corel groups, 18 Jan 2005:

QPW v10 and above use a new charting engine, which treats dates 
differently than previous versions for numeric axes (like the Y axis, or 
both the X and Y axes in XY charts).  You've got to go through some new 
steps for now, for these numeric axes.  It's clumsy, but we're hoping 
Corel puts thumb-screws to the people who produced the engine to change 
this back to the old way.

1.  Your numeric axis series values MUST conform to
     a new format.  The cell cannot just contain numeric
     data using the date's Julian Time/Date #.  If you
     want dates or times to appear correctly on your
     axis you must first set the axis values for the
     date and/or time as a single number in the
     following format : YYYYMMDDhhmmss.
     For example :

          20011231235959 = December 31st, 2001 at 11:59:59 pm.

     This is not a suggestion, this is MANDATORY.  STUPID,
     but mandatory, nonetheless.

2.  RightClick the axis, and choose "? Axis Properties",
     where "?" is the axis in question (X or Y).

3.  Choose the "Scale" tab, and turn off "Automatic"

4.  Set your "Max Value" to the NUMERIC value of your most
     recent date/time (which is the highest number).

5.  Set your "Min Value to the NUMERIC value of your oldest
     date/time (which is the lowest number).

6.  Choose the "Numeric Format" tab, and set "Category" to
     "Date, then "Format" to your desired format.

7.  If you press <Help> at this point, click <How To>, and
     then <Display> in the next dialog, you will be
     presented with help on how to set the Numeric format.
     You absolutely *must* conform to the two notes there,
     which are reproduced below :

Notes
==========
· In order to format dates and times to properly display in a chart, you 
must first concatenate the date and time as a single number as follows: 
YYYYMMDDhhmmss. For example, 20011231235959 = December 31st, 2001 at 
11:59:59 pm.

· Maximum, minimum, and increment values must be set precisely in the 
axis properties dialog box to allow dates to properly appear on the axis 
of your chart. For example, to create a y-axis scale that ranges from 
the start to the end of the year 2001, incremented by month, you would 
use 20011201000000 as the Max value, 20010101000000 as the Min value, 
and 100000000 as the Increment value.

-- 
=====================
Michael Scott [C_Tech Volunteer - Quattro Pro]

-- 
Good wishes!
Roy Lewis
C_Tech volunteer
(UK)

Hi,

I posted a thank you earlier, but it seems to have not been posted. Perhaps
I commented on the elaborate procedures needed to achieve a stable and
accurate X-axis made up of dates. One would never wish to imply that the
procedure you outlined is anything other than self-evident, and wholly
compatible with standard industry practice.


Jim Hargan

On Mon, 04 Feb 2008 12:34:07 GMT, lemoto wrote:

> Uli:
>> (I can only give generic advice here, since I don't have v12 --
charting is one 
>> of the reasons why I've stayed with v8.
> 
> I think that this applies a) to the chart type that Uli suggests and b) to
QP12. 
> The issue has now been improved - I do not remember at which stage the
improvement 
> was applied.
> 
> This is from a post in the Corel groups, 18 Jan 2005:
> 
> QPW v10 and above use a new charting engine, which treats dates 
> differently than previous versions for numeric axes (like the Y axis, or 
> both the X and Y axes in XY charts).  You've got to go through some new 
> steps for now, for these numeric axes.  It's clumsy, but we're hoping 
> Corel puts thumb-screws to the people who produced the engine to change 
> this back to the old way.
> 
> 1.  Your numeric axis series values MUST conform to
>      a new format.  The cell cannot just contain numeric
>      data using the date's Julian Time/Date #.  If you
>      want dates or times to appear correctly on your
>      axis you must first set the axis values for the
>      date and/or time as a single number in the
>      following format : YYYYMMDDhhmmss.
>      For example :
> 
>           20011231235959 = December 31st, 2001 at 11:59:59 pm.
> 
>      This is not a suggestion, this is MANDATORY.  STUPID,
>      but mandatory, nonetheless.
> 
> 2.  RightClick the axis, and choose "? Axis Properties",
>      where "?" is the axis in question (X or Y).
> 
> 3.  Choose the "Scale" tab, and turn off "Automatic"
> 
> 4.  Set your "Max Value" to the NUMERIC value of your most
>      recent date/time (which is the highest number).
> 
> 5.  Set your "Min Value to the NUMERIC value of your oldest
>      date/time (which is the lowest number).
> 
> 6.  Choose the "Numeric Format" tab, and set "Category"
to
>      "Date, then "Format" to your desired format.
> 
> 7.  If you press <Help> at this point, click <How To>, and
>      then <Display> in the next dialog, you will be
>      presented with help on how to set the Numeric format.
>      You absolutely *must* conform to the two notes there,
>      which are reproduced below :
> 
> Notes
> ==========
> · In order to format dates and times to properly display in a chart, you 
> must first concatenate the date and time as a single number as follows: 
> YYYYMMDDhhmmss. For example, 20011231235959 = December 31st, 2001 at 
> 11:59:59 pm.
> 
> · Maximum, minimum, and increment values must be set precisely in the 
> axis properties dialog box to allow dates to properly appear on the axis 
> of your chart. For example, to create a y-axis scale that ranges from 
> the start to the end of the year 2001, incremented by month, you would 
> use 20011201000000 as the Max value, 20010101000000 as the Min value, 
> and 100000000 as the Increment value.
> 
> -- 
> =====================
> Michael Scott [C_Tech Volunteer - Quattro Pro]

Jim:
> I posted a thank you earlier, but it seems to have not been posted.

It happens.-(}
Glad you have things working now, as seems to be the case.

> Perhaps
> I commented on the elaborate procedures needed to achieve a stable and
> accurate X-axis made up of dates.

You would not be the first.-)}
As I noted, I believe that smoother operation is possible in later versions.
-- 
Good wishes!
Roy Lewis
C_Tech volunteer
(UK)