[Solved] Creating Plot Symbols

[rochjey]

This seems to be a longstanding topic, but my searches did not lead to any new solutions and hence this post.

Users of Calc have noted that the plot symbols offered are very few and that very standard symbols like unfilled circles, squares, etc. are not available. There posts go back to 2009! Looking around, I found that one can generate a SVG file and then select the file in the "Data Serice/Line" tab.

I created an unfilled circle using Draw, saved the file and then selected it for the "Icon". The circles do appear, but are badly offset from where they out to lie. The general shape of the "curve" looks fine, but the centres of the circles are not where they ought to be -- there is a shift along, both, x and y axes.

As a complete newbie to SVG, I can be doing things in a completely wrong way. Would be grateful if I can get some help on how the make owns own simple symbols for Calc -- very basic ones like unfilled circles and polygons.

[Zizi64]

Can you upload some sample files here?
What do you mean as "plot sysmbols"? Dou you want to create user defined icons for the toolbar?

[Lupp]

"Plot Symbols" seems not to be a well defined term in AOO (or for any successor of OO.o). The only reasonable context it should be associated with, imo, is the formatting of lines in "charts", and there is a "plot"-related help entry in AOO.
You obviously already know:
If you go "Format Data Series>Line>Icon" for one of the lines in a X-Y-Diagram (or a so-called Line chart) you get lots of options among them "Gallery/Bullets" and "From file...".
What more do you need?

I personally never use the options "Gallery" or "From file". Therefore the question: Doi you also get the bad positioning with bullets from the gallery?

BTW: Use a limited choice. The offered standard symbols mostly suffice. A chart should communicate information in a visualizing form. It's not for impressing spectators or for selling to netflix.

...but are badly offset from where they ought to lie.

I don't get such an effect with the gallery bullets or with my smallest jpeg graphics I tested with. What graphical format did you use? Did you already check the working bullets and graphics with an appropriate editor of the format for special properties?

And: Attach the additional bullet (or whatever) you added as a file.

[rochjey]

By plot "symbols" (as scientists and engineers use the term) I mean what you call an "icon". Yes, I see how one can choose an"icon" from the 'Select/Symbol' submenu (ah! "Symbol" ... where did that word come from!) of DataSeries/Line dialogue box, as you have surmised. I also am aware of other plot symbol choices that can be obtained from the 'Select' submenus of 'From File' and 'Gallery'.

What I am looking for are simple "icons" (?, or should one call them symbols?) like filled and unfilled circles, squares, triangles and diamonds. Some of these of available in Calc (filled diamonds, triangles, etc. where a fill colour can be chosen on the 'Line' property side, not on the 'Icon' side), but the simplest ones that one can find in other plotting/graphing software like circles are not available. That is what I tried to create.

I drew the circle (black line, no fill) in Draw and exported the file as a SVG file as I see that 'Gallery' files are SVG files. I then tried to use this circle by using the 'From File'. The circles corresponding to the the data points on the plot, but they were offset. I did open up the SVG file to see what it was like. This is what it is:

-----------------

<?xml version="1.0" encoding="UTF-8"?>

<svg version="1.2" baseProfile="tiny" width="215.9mm" height="279.4mm" viewBox="0 0 21590 27940" preserveAspectRatio="xMidYMid" fill-rule="evenodd" stroke-width="28.222" stroke-linejoin="round" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve">
<g visibility="visible" id="MasterSlide_1_Default">
<desc>Master slide
</desc>
<rect fill="none" stroke="none" x="0" y="0" width="21590" height="27940"/>
</g>
<g visibility="visible" id="Slide_1_page1">
<g>
<path fill="rgb(207,231,245)" stroke="none" d="M 9063,6587 C 9747,6587 10270,7109 10270,7793 10270,8477 9747,9000 9063,9000 8379,9000 7857,8477 7857,7793 7857,7109 8379,6587 9063,6587 Z"/>
<path fill="none" stroke="rgb(0,0,0)" id="Drawing_1_0" stroke-width="102" stroke-linejoin="round" d="M 9063,6587 C 9747,6587 10270,7109 10270,7793 10270,8477 9747,9000 9063,9000 8379,9000 7857,8477 7857,7793 7857,7109 8379,6587 9063,6587 Z"/>
<rect fill="none" stroke="none" x="7858" y="6588" width="2414" height="2414"/>
</g>
</g>
</svg>

-------------------------------

The Gallery symbols are too flashy and garish for what I need. Using filled and unfilled symbols of the same shape is very good for comparing the data of two 'settings' of same underlying variable -- say, hot and cold. At work I used PV Wave and MATLAB for nearly three decades and, if in a hurry, I would even use Excel. All of them offered the simple symbols whose properties (line, line colour, fill colour, etc.) can be chosen. In particular, I would like to stay away from colour -- hence the need for more shapes with black lines and optional black fill.

Just wondering I can come up with my own "Symbols".

And, if I wanted to "sell" trivia, I can do that with Excel. I am trying to get some plots for a physics presentation and, eventually, a paper.

Some ancient stuff that addresses what I am trying to get at:

viewtopic.php?t=9439

(Note: "(Those 3D balls in "Gallery" are too fancy for scientific charts). Also it is not possible to use an empty symbol (with white or transparent interior)) -- from 2008!!!
Following the link to "Issue 3582" in acknak's post leads to

https://bz.apache.org/ooo/show_bug.cgi?id=3582

which, again, talks about the difficulties for technical/engineering/scientific plotting.

Appears to be a long standing issue, but I am willing to do a bit of coding to get custom symbols if they are not available in OO Calc.

Otherwise, I guess it is gnuplot (suggested in the page quoted above) as I cannot afford either PVWave or MATLAB for the home

[rochjey]

Forgot to answer one important question.

Yes, I did try using several choices in the Gallery. They work as advertised -- no offset. Obviously, the SVG file I generated is not right (for the purposes).

Out of the many bullet choices available in Gallery, Target-Blue is so close! It has filled and unfilled circles in the same symbol!! If I could only separate them .....

[rochjey]

Re: the "offset" symbols -- is this the cause?

I may have a clue here. By varying the size of the circles in plot via Format Data Series/Line/Icon I find I can
move the line around! In fact making the size (width and height) small, I can get the points very close to where
they ought to be!! And when I double click on one the circles, I see a the green rectangle anchor points.

I think this particular problem arises from my saving the entire Draw canvas to the SVG file. I think that the centre
of the canvas is at the data point, but as the circle is offset in the canvas, it gets offset on the plot. If I have
drawn the circle at the centre of the Draw canvas, I am pretty sure things would be ok.

And, I need to find a way of trimming of all the surrounding white space around the square circumscribing the
circle. All the is wasted space. I now seems that it is Draw that I should learn to use!!

[rochjey]

I think I got it, but it still lacks the flexibility I would life (will come to it later).

In Draw, I created a 1 in x 1 in page (using Format/Page) and then drew the circle, centred on the
page and diameter of 1 in. I saved this to an SVG file and when I use this file, everything is just fine.
The contents of the file are given below.

-------------------------------------------

<?xml version="1.0" encoding="UTF-8"?>

<svg version="1.2" baseProfile="tiny" width="25.4mm" height="25.4mm" viewBox="0 0 2540 2540" preserveAspectRatio="xMidYMid" fill-rule="evenodd" stroke-width="28.222" stroke-linejoin="round" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve">
<g visibility="visible" id="MasterSlide_1_Default">
<desc>Master slide
</desc>
<rect fill="none" stroke="none" x="0" y="0" width="2540" height="2540"/>
</g>
<g visibility="visible" id="Slide_1_page1">
<g>
<path fill="none" stroke="rgb(0,0,0)" id="Drawing_1_0" stroke-width="25" stroke-linejoin="round" d="M 1270,1540 C 1220,1540 1178,1529 1135,1504 1092,1479 1061,1448 1036,1405 1011,1362 1000,1320 1000,1270 1000,1220 1011,1178 1036,1135 1061,1092 1092,1061 1135,1036 1178,1011 1220,1000 1270,1000 1320,1000 1362,1011 1405,1036 1448,1061 1479,1092 1504,1135 1529,1178 1540,1220 1540,1270 1540,1320 1529,1362 1504,1405 1479,1448 1448,1479 1405,1504 1362,1529 1320,1540 1270,1540 L 1270,1540 Z"/>
</g>
</g>
</svg>

-------------------------------------------

So, almost there! What I wish one had control over is the thickness of the line of the circle from within Calc. When I use this to plot data, the lines are too thin. So, I guess one has to create a series of SVG files with unfilled shapes with different line thicknesses (3 or 4 ought to do) and see which one works best for a give plot.

[rochjey]

OK. Easier to have just one SVG file and monkey with the "storke-width" value in

<path fill="none" stroke="rgb(0,0,0)" id="Drawing_1_0" stroke-width="100" stroke-linejoin="round" d="M 1270,1540 C 1220,1540 1178,1529 1135,1504 1092,1479 1061,1448 1036,1405 1011,1362 1000 ......................

I had the value at 40 initially and by increasing it in steps, saving the file and then reloading the symbol, I could see
what worked. I settled at a width of 80.

All done!