On 17/12/2024 00:51, Regina Henschel wrote:
Devansh Varshney schrieb am 14.12.2024 um 13:49:
Thanks, Regina, for such detailed information. This helped me to
approach the
import/export for the Histogram Chart.
I have added changes to the ODF Export for the Histogram Chart.
Have to add support for the Import and addition in the RNG file.
https://gerrit.libreoffice.org/c/core/+/177364
Would anyone from the community be able to help me by reviewing the PR?
You have added the 'bin' related information to the <chart:series>
element. A <chart:plot-area> element can have several <chart:series>
sub-elements. I guess, that you do not want to allow several series in
the same histogram. Excel does no allow it. Restricting it in the schema
is difficult. (Or do you have an idea, Michael?) I suggest to restrict
it in the specification text.
likely possible, but it sounds like it would make the schema a lot more
complicated for very little gain.
You export the labels for the x-axis as loext:BinRange. I would not
export them at all for these reasons:
(A) Excel does not export that information.
(B) The chart has a reference to the area of the data source in the
table. The content of this area might come from an external source, e.g.
a database engine. When the file is loaded, this data might be refreshed
and changes. Thus the bin labels and their frequency values might not
fit to the information that are put into the file when saving.
You write the 'bin' related information as attributes of the
<chart:series> element. You should consider to use one child element
instead, that contains all needed information. That way you can use a
dedicated context when loading the file. The schema would get one new
child-element for the <chart:series> element and a new section for this
new element itself. Michael, what do you think?
i'm afraid i don't know enough about charts to have an opinion on that.
Different variations (types) are possible for the histogram chart. You
need to specify in the text how the bins are calculated. Especially how
'automatic' works and how overflow and underflow bins influence the bin
intervals.
You use two attributes for a underflow bin, one whether such underflow
exists and one with its value. I think that can be combined. In
implementation and schema it would be optional. The specification text
then needs to contain, what is used, when this attribute is missing.
Same for overflow. Excel has data type ST_DoubleOrAutomatic.
is it so that an absence of the value attribute could mean that the
feature is disabled? that could work...
The 'binCount' and 'binWidth' information are coupled to the chart
variants FrequencyType=2 'Number of bins (BinCount)' and FrequencyType=1
'Bin Width'. You write them in all cases. Especially for variant
FrequencyType=3 'By Category' the binWidth attribute is meaningless. On
the other hand for the variant FrequencyType=1 it is mandatory. Michael,
do you have a nice idea for the schema?
something along these lines?
<choice>
<group>
<attribute name="FrequencyType">
<value>1</value>
</attribute>
<attribute name="BindWith">...</attribute>
</group>
<group>
<attribute name="FrequencyType">
<value>2</value>
</attribute>
<attribute name="BinCount">...</attribute>
</group>
...
</choice>
could add some "<optional>" around the attributes if necessary...
In implementation they might both be optional with an assert, if they
are missing in their corresponding FrequencyType. For UNO it might be
sufficient to make them optional and mention the dependencies in the text.
Kind regards,
Regina
