Interested in the new Chart features that will be available in OOo 3.2? Have a look:

tags: chart features openoffice.org

Recently I did some performance measurements on charts. I used a big line chart with 13 series each with 4000 data points. The whole cycle of editing was measured: load the ods document (bright green) enter the charts edit mode per double click (orange) change the chart (red) leave the edit mode (dark green) and save the ods document (yellow). The whole cycle needs about 4 minutes. Where does the time go? Look at the chart on the right side, where some of the more expensive calls are identified. It turns out that there are some superfluous calls that consume away the users time without justification! They are marked with a fat black border. The first is Issue 101925. A metafile replacement image is requested during edit mode. This is not necessary as the chart uses the SdrView for rendering while in edit mode. The second problem identified is Issue 101928. Painting was actually performed twice instead of once - both while entering the edit mode and also after changing the chart. Eliminating those calls did speed up a single chart change within edit mode from 1:50 min to 0:19 min, that is round about 5 to 6 times faster now with this big document! :-) As OLE objects are rendered via a replacement image while not in edit mode now the expensive creation of the replacement image  needs to happen at the end of editing. So leaving the edit mode takes longer now. But in sum we have saved time. Even more if one takes into acount that usually more than one change is performed when editing a document. You will not need multiples of 1:50 min anymore but only multiples of 19 seconds instead.

Look at the chart below how the times of the different steps compare between OOo 3.0, dev300m47 and a changed dev300m47 including experimental fixes for the above identified issues:

tags: chart openoffice.org performance

tags: 2d 3d chart draw drawinglayer graphics impress openoffice.org

Interested in the new Chart features that will be available in OOo 3.1? Have a look:

Flexible positioning of axes and axis labels The axis line and axis labels can now be positioned more flexible. You can find the settings on a new tab page 'Positioning' in the properties dialog of the axis. As shown in the example you now can have the axes crossing in the middle separating the coordinate system into the four quadrants, as many people are used to from school. This issue was the most voted feature request recently within the chart with something around 80 votes.
Plotting of missing values Did you ever had spreadsheet data where some values were missing? You now can decide how those missing values should be plotted: leave a gap, assume zero instead or simply continue the line (issue 65549).
Right to left Charts & Bi-directional writing For OpenOffice.org 3.1 Charts have been prepared to work proper in a right to left environment. So now when your Office runs in RTL mode new Charts are created in right to left layout. If you want to do some fine tuning you can change all the involved options of course especially you now can decide explicitly about the writing direction of the various text elements inside a chart (issue 14365). Do not forget to enable enhanced language support for complex text layout, to show the additional setttings.

tags: chart features openoffice.org

Did you ever want to take the values for error bars in a chart from cells in a spreadsheet? Then you are maybe one of those who voted for Issue 366. As you can see by the issue number this is quite an old one. And it has over 130 votes. So, if you are interested in this feature, there are good news: it is implemented, integrated into the DEV300 code-base and thus will make it into OpenOffice.org 3.0!

It was done in the CWS chart20, which was integrated into DEV300.m2 (as chart20_DEV300). So, if you know how to do a build yourself, you can do this for this master workspace or a newer one. I suppose, there will soon be DEV300 developer snapshot builds available on the OpenOffice.org Download Website.

Here is an example for a chart that has error bars at its data points which use their values from spreadsheet data. In this example both, the positive and negative values share the same range of cells, so they have the same extent in both directions. Of course these ranges can be different as well.

 
In addition to this long awaited feature, the automatically calculated error-bars now also support standard error (also known as standard deviation of the mean). So now, there are the error types:

• constant value (positive and negative)
• percentage (one parameter for both, positive and negative)
• standard error
  
• standard deviation
• variance
• error margin (one parameter)
• cell-range (one for positive and one for negative values)

Technically, it would be no problem to have separate parameters for positive and negative values for percentage values and error margins as well, but the ODF file format currently does not allow this.

While implementing this new feature, the dialog for error bar properties had to be adapted. In that course, it was also improved in general. You might have noticed that in OpenOffice.org 2.3 there is one dialog/tab page for statistic properties that contains error bars as well as regression curves (now called trend lines). This dialog was split up into two dialogs for the trendline equation feature. The trendline part was already improved there. Now, the second part was done by cleaning up the error bar dialog. This is how it looks now:

tags: chart openoffice.org

In the upcoming OpenOffice.org 2.4 release there will be some nice new features in the Chart. And here they are in an overview. You can get more detail on the Wiki page about Chart Features for OOo 2.4. Thanks to Tony Galmiche there are nice screen shots of the new features together with the corresponding dialogs to access them.

If you want to try out the new stuff you can download a pre-release version. See this announcement for more information about the latest developer snapshot.

Equation and Value of R² for Trend Lines Now, it is possible to display the equation for a trend line (regression curve) next to it. The formula object can be moved around, formatted with a number format, font and graphical formatting. Alternatively, or in addition, the correlation coefficient R² can be displayed in the formula object. This has already been announced on GullFOSS. Wiki
Reverse Axes Axes can be reversed, i.e. they point in a different than usual direction. In the example the y-axis points down from the top, instead of the usual orientation. You can also reverse the category labels of a category axis. Wiki
Display Bars on Different Axes next to Each Other You can attach some bars of bar or column chart to the first axis, and some to the second one. As a result the bars are grouped for each axis and displayed one group before the other. Now, it is possible to arrange the bars side-by-side even when they are attached to different axes. In the example, the blue series is attached to the left axis, while the orange and red series are attached to the right axis. Wiki
Number Format for Data Labels You can set individual number formats for the value displayed in a data label, as well as for the percentage. (Wiki) Display both, the Value and the Percentage It is now also possible to display the value and the percentage at the same time. You can choose a separator like a comma, semicolon, space or newline. (Wiki)
Flexible Placement of Data Labels Data Labels can now be positioned at different anchor points of the data point objects. In the example you can see that in a bar chart there are the absolute positions above, below and center. In addition, it is also possible to set a position depending on the sign of the value. So, outside means below for negative values, and above for positive ones. Wiki
Best Fit Data Label Positioning for Pie Charts In addition to the before-mentioned positions for data labels, there is a best-fit algorithm for pie charts that tries to place labels without overlapping. Especially for smaller segments overlapping happens quite frequently, which can now be avoided. Wiki

tags: chart features openoffice.org

Issue 7998 is quite old, as you can see by the low number. It was submitted half a decade ago. It's issue: equations for trend-lines. This is one of the issues that haven't been done for quite a long time due to the re-implementation of the chart. Now, that we have the new chart in OpenOffice.org 2.3, I took care of it and finished almost by now. The UI is still not optimal. As we have a nice code-base now, the implementation was for sure much more fun than it would have been for the old implementation, but it was far more than a check-box (that's what was stated at one point in the comments of issue 7998) — I can tell you that much!

This is an example using the new feature. I chose only linear regressions in this example, but of course this feature works for all supported regression types. I was looking for some data that can nicely be used for regression curves, and found some here. And only after I created the chart I noticed that the new feature is really useful, you can see:

• R² is very small, i.e. the linear regression is not a very good match, or in other words the variance of the data is quite large.
• Ignoring the first fact you could interpret the equation and find out that the temperature rose about two percent over the years. It's up to you to conclude global warming out of this data, though.
  

So, whenever chart17 is integrated, this feature will make it into OpenOffice.org.

What you can do now is, insert an equation for each regression curve (that's how trend-lines are still called in OOo). You can display the equation itself, the square of the correlation coefficient R, or both together. The text can be formatted with borders, a fill style and different fonts and font effects. The number format for all numbers appearing in the formula or in R² can be set. The equations are initially placed on the left and aligned with the top of the bounding box of the curve, which is not the most sophisticated place, but you will usually move the formula around anyway to have it at a place where it is well visible.

The necessary file format extensions for this feature have been integrated into the ODF 1.2 draft by the OASIS OpenDocument TC.

P.S.: For those who are wondering about the smooth rendering: this is a screen shot of an exported PDF.

tags: chart openoffice.org

tags: chart community openoffice.org

tags: chart community openoffice.org

In the OpenOffice.org Wiki there is a page about the Chart. It became more and more a mixture of miscellany. So, I decided to clean up this mess a bit. The page now contains four major sections:

• Helping with the Chart. For developers there are some links that may be helpful for starting coding. For people who like doing QA, there are some predefined IssueZilla queries.
• Features. Grouped by different releases and features that are not yet decided upon. This was mostly done be Tony Galmiche.
• Technical Articles. Some of the things that were on the main chart page are now moved to separate sections. Any additional articles that go into details of the chart, either design or implementation, should go to Chart/Article Name and get a link here. We should avoid to put too many content on the main page.
  
• People. Overview about who is involved in the development of the Chart. If anybody thinks he is missing, go ahead, do changes on the page or drop me a note.

The main focus of these pages is on development. So, the section Development should be the one to grow most. I hope you find this page clear and useful. Any suggestions for improvement of this page are welcome.

tags: chart openoffice.org wiki