Recent Posts

21

Tips and Tutorials / If the transparent PC plot window is blank, increase the alpha value

« Last post by Ron D. on January 25, 2015, 11:35:40 PM »

The menu option Plots-->New Transparent PC Plot opens a new window in which the current PC plot is displayed with a level of transparency set by the alpha value. (The Java Real-time Environment, or JRE, must be installed on your PC for this window to appear.) For a given number of polylines, there will be an alpha value below which the window will not show any lines at all. This might happen if you had previously reduced the alpha value when viewing a larger dataset.

If you don't see any polylines in this window, increase the alpha value until you do. Pressing the numbers 0 through 9 on the keyboard will assign an alpha value from 0.01 to 0.50, where 1.00 represents no transparency at all. Pressing the UP/DOWN arrows on the keyboard will fine-adjust these values. These controls, and those for changing the width of the polylines, are listed when pressing "h" to see the help in that window.

Ron

22

Tips and Tutorials / Locking a 2D scatterplot

« Last post by Ron D. on January 25, 2015, 11:22:12 PM »

Pressing "k" when a 2D scatterplot is the active window will "lock" the scatterplot in its current color scheme. The window title will indicate that it is locked. Selections cannot be made in a locked scatterplot, and any changes to the main PC plot or other scatterplots have no effect on it. This allows two or more scatterplots to be created that have different color brushing as a means of comparison.

Pressing "k" again when a locked scatterplot is the active window will unlock it, and it will automatically update to the color brushing of the PC plot and any other unlocked scatterplots.

Ron

23

Tips and Tutorials / Boolean operations when selecting lines or points

« Last post by Ron D. on January 25, 2015, 11:14:47 PM »

This is described in the User's Manual and the Help-->Tips menu, but just to be clear on this, after you select a group of lines in the PC plot or points in a 2D scatterplot, you can modify that selection as many times as you wish using Boolean operators:

- Press Ctrl while swiping to OR the new selection

- Press Shift while swiping to AND the new selection

- Press Ctrl-Shift while swiping to XOR the new selection

Also, you can choose the Brushes-->Toggle Selection to perform a NOT operation on the current selection. It is sometimes easier to select the lines you don't want and then toggle that selection rather than directly selecting the lines that you want.

Selection combinations can be performed in the PC plot or in any 2D scatterplots, in one or the other or mixed.

Ron

24

Tips and Tutorials / Range brushing only selected lines

« Last post by Ron D. on January 25, 2015, 10:52:18 PM »

Range brushing an axis of the PC plot consists of selecting that axis by clicking on its name while pressing ALT, and then either choosing the Axis-->Range Brush option or pressing "r" (sometimes you may have to press "r" twice). Two to eight brushes (colors) will be applied depending on the setting in the Options-->Plot Settings menu.

When no lines are selected, this clears all existing brushes. Then all lines are re-brushed in a spectrum from the bottom of the axis to the top of the axis. This is a very effective way to quickly show structural trends in the data, particularly when there is significant overplotting.

However, if any lines are selected when range brushing happens, only the selected lines will be range brushed. They are brushed in a spectrum in a range from the lowest selected line on that axis to the topmost selected line. All other lines are unbrushed. This allows the range brushing to be dependent on another variable or a Boolean combination of other variables.

For example, in the standard selection process you might first select all lines that pass through a given set or range of values on the Variable A axis, or perhaps those that pass through those values but not other sets of values on the Variables B and Variable C axes. Then you can select the Variable D axis and range brush it, and you range brush just those lines you are interested in, with the spectrum ranging from their minimum value to their maximum value of Variable D.

Ron

25

Tips and Tutorials / Move the cursor to re-enter the window after resizing!

« Last post by Ron D. on January 25, 2015, 10:21:03 PM »

When you resize a plot window, you generally need to move the cursor from outside to inside the window to re-scale the plot inside that window to the new dimensions of the window. This is true whether you drag a corner of the window to resize it or click on the maximize/minimize icon in the upper right corner of the window. Sometimes the plot resizing will occur without realizing that your mouse has moved the cursor into the window, however, as it is natural to re-enter the window to do something with the plot.

If the plot does not resize, use the mouse to move the cursor outside the window and then back in. If this does not work, resize the window again and repeat the re-entry of the cursor. This may happen occasionally when you maximize the window to full-screen, as there is no "outside" to move the cursor in from.

Ron

26

Tips and Tutorials / If swiping reacts too slowly, select with corner points

« Last post by Ron D. on January 25, 2015, 10:06:23 PM »

When the dataset size is large, you may find that swiping with the mouse to select lines in the PC plot is slow to react. This will not happen in 2D scatterplots because points are faster to redraw than polylines.

In the Options-->Plot Settings menu you can choose to replace the mouse swiping function in only the PC plot with a mechanism where you click on the corner points of a selection box. When this option is set, you first click on one corner point and then click on the diagonally opposite corner. A selection box is immediately drawn. If you are not satisfied with this selection box, you can click a different second corner and the selection box is redrawn with this new corner. You can continue to click second corners until you are satisfied with the selection box, and then press Enter to accept it and select all lines passing through it. If you wish to click on a new first corner, press ESC to start over with the first corner.

Ron

27

Tips and Tutorials / One-time setup to PDF settings for paper size and transparency

« Last post by Ron D. on January 02, 2015, 01:14:59 AM »

This information is in the User's Manual, but it doesn't hurt to include it here on the forum. There is a one-time setup required in Adobe Distiller to match paper size with the PDF export setting in Sliver and to enable transparency when exporting plots to a PDF.

Open Adobe Distiller and choose an option for Default Settings (choose Press Quality or High Quality Print for best results). Then select the menu option Settings-->Edit Adobe PDF Settings. In the main window, change the Default Paper Size to match the paper size selected in the Sliver Postscript/PDF Export Settings (in Landscape mode). For example, for the “8.5x11 letter” export setting in Sliver, the Width would be set to 11.0 and the Height to 8.5 with Units of “Inches.”

Click on the “Save As…” button, give your options file a new name and remember the folder where Distiller will save it, and then click Save.

Then go to that folder, open the new options file you just named, find the line with the phrase “AllowTransparency” near the top of the file, and change the value from “false” to “true” and save the file.

This is the settings file that should always be the default selected in Distiller. Once a PDF is created with transparency, it will always be shown with transparency to everyone without any settings changes.

Ron

28

General Discussion / References on parallel coordinates and the Grand Tour

« Last post by Ron D. on January 01, 2015, 06:00:20 PM »

I have collected a good number of articles and other references on the use of parallel coordinates for data visualization. I also have some articles on the use of the multidimensional Grand Tour. If you would like to have a look at them, please use the information from the Contact tab along the top of the main Sliver pages at http://www.sliversoftware.comto email me.

Ron

29

Tips and Tutorials / Re: Forcing the same range on all axes

« Last post by pmartel on January 01, 2015, 09:36:48 AM »

Thanks Ron,

I was going to ask about how to do this.

  --Phil

30

General Discussion / Other parallel coordinates software programs

« Last post by Ron D. on January 01, 2015, 04:52:31 AM »

Appendix A of the Sliver User's Manual provides a list of other free software programs that support parallel coordinate plots and are worth investigating. I specifically recommend having a look at Mondrian at http://www.theusrus.de/Mondrian/ for extremely large datasets of up to a million records, which Sliver simply can't handle.

The Appendix lists the similarities and differences between these other programs and Sliver. There are indeed significant differences in features I find noteworthy, which was ultimately the impetus for me to create Sliver.

Ron