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cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<div class="moz-cite-prefix">On 09.01.21 00:13, Berthold Stoeger
wrote:<br>
</div>
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<pre class="moz-quote-pre" wrap="">Hi Christof,
Thank you for the detailed report. A few short comments in-line.
On Freitag, 8. Jänner 2021 23:25:07 CET Christof Arnosti via subsurface wrote:
</pre>
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<pre class="moz-quote-pre" wrap=""> * When I select date(yearly) as base variable and buddies as data, bar
charts have a yellow warning in the drop down. Why's that?
</pre>
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<pre class="moz-quote-pre" wrap="">A bar-chart is not recommended with continuous data. A histogram is preferred.
However, as you note, the warning icon is not a good UI element.</pre>
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<p>I suspect the warning bar is indeed a good UI element. The
difference between continuous and categorical variables will be
defined in the user manual, once I get to writing that text. It is
not good practice to mix the use of these two different types of
information and a solid warning is the least that I would expect.
Personally I would prefer a red cross over each of the icons for
the inappropriate graphs.<br>
</p>
<blockquote type="cite"
cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<pre class="moz-quote-pre" wrap="">
In case of sparse data I have likewise found bar charts to be more convenient
than histograms. On the other hand, I see the argument that they can be
misleading if only a few cups of data are missing.</pre>
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<p>Zero data are useful information. If you did no dives between 30
and 50 meters, but yet did do dives down to 60m, then the blank
areas in the range 30 - 50 meters represent valid data: no dives
were executed for those depths. To ignore zero data is to
misrepresent the information. This is one of the cases where using
a bar graph to represent depth data is statistically wrong,
leading to erroneous conclusions.<br>
</p>
<blockquote type="cite"
cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<pre class="moz-quote-pre" wrap="">
</pre>
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<pre class="moz-quote-pre" wrap=""> * The trend line does not always appear in the scatter graph. For
example, when I select date (no binning) / depth, there is no trend
line, except for when I filter out very shallow depths. For water
temp over date I get a trend line right away. I'm sure that's
correct and there is a statistical reason for this that I'm not
aware of.
</pre>
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<pre class="moz-quote-pre" wrap="">Indeed, there is a statistical test whether there is a linear regression.
Willem knows more.
</pre>
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<p>The red trend line (=linear regression line) is only shown for
scatterplots where there is a statistically significant
relationship between the two variables that are plotted. When
there is no line, there is no relationship. Presenting a trend
line in this case would be misleading and leads to erroneous
conclusions. This will be explained in the user manual.<br>
</p>
<blockquote type="cite"
cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap=""> * When I select Buddies over Date(yearly), and then grouped vertical
bar chart, the bars are oddly spaced. I suspect that for every buddy
there is a bar every year, even if the number is zero. This might
make sense in some cases (for example water temperature), but in the
buddy case it looks weird. Maybe add some "don't show empty bars"
option for the grouped bar charts?
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">I'm not an expert in charts, but I think that this is how grouped bar charts
should be done(?). In the case of sparse data a stacked chart is probably
preferred.
</pre>
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</blockquote>
In this case the discussion above is pertinent.<b><u> Zero data are
real data</u></b><b>.</b> <b>Data of absence does NOT mean
absence of data.</b> If a bar is empty it indicated that the buddy
did not dive that year. The information indicating you did not dive
with buddy X during 2020 is just as valuable as the information that
you dived with her 30 times in 2019. Why make the graph pretty by
eliminating the bars with zero height??<br>
<blockquote type="cite"
cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<pre class="moz-quote-pre" wrap="">
</pre>
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<pre class="moz-quote-pre" wrap=""> * Is there some Export functionality planned? For example simple image
export of the graph?
</pre>
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</blockquote>
</blockquote>
Screen capture software can easily be used to save a graph in almost
any graphical format except as vector graphics.<br>
<blockquote type="cite"
cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<blockquote type="cite"> </blockquote>
<pre class="moz-quote-pre" wrap="">Not yet.
</pre>
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<pre class="moz-quote-pre" wrap=""> * For me the Filter GUI seems a bit unintuitive. When there is no
constraint present, it's not very obvious that constraints can be
added (the button is in an odd place). A change to make it more
obvious could be to add a "Constraints" heading below the fulltext
search, and move the button there? And maybe also display a "No
constraints" text when no constraint is set? I really like the
"Filter sets" functionality!
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">Yes, I also noticed that - especially in the German translation - the filter
is quite inaccessible.</pre>
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</blockquote>
If you click on "Add constraint", a list of all possible constraints
is shown. I Need to look at the user manual to see if this aspect
has been explained clearly. This is possibly my fault.<br>
<blockquote type="cite"
cite="mid:ad70d34a-1348-ba78-1b3c-76eb403bb772@charno.ch">
<blockquote type="cite" cite="mid:6138685.B7R1nPKWHM@laptop">
<pre class="moz-quote-pre" wrap="">
</pre>
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</blockquote>
<p>It is fantastic that you actually looked at the statistics option
and that you spent time to think about how it works or how it
could work. Your comments are extremely valuable. Once the user
manual for this has been written, hopefully many thing will become
more clear, but your interpretation of the information and
defining your needs are very valuable. Thank you for doing that. <br>
</p>
<p>Kind regards,</p>
<p>willem</p>
<p><br>
</p>
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