On 2012-08-30 02:26-0700 Jerry wrote: > Does the Tk interactive method allow the user to use a mouse to interactively select a rectangular portion of the plot for zooming? This would certainly be useful and then I would have an actual personal interest in this work. Do any of the interactive devices allow this? X, Aquaterm and Qt do not--those are the only ones that I have tried.
This question introduces a new topic, so I am using a different subject for it. The xwin, tk, xcairo, and qtwidget devices all allow mouse and keyboard interaction. Try example 1 in C with the --locate option to demonstrate this for yourself. With each mouse button or keyboard character hit, the position and which mouse button/key was hit is returned (with the exception of qtwidget where the key/mouse identification is still missing.) The mouse button/key identification and position is all that is required from our devices to allow higher-level interactive capability such as zooming. Note that high-level interactive use has to be programmed at the application level. For example, I used an interactive plotting system in the early 80's built off of plotting device drivers for plotting software available at that time which had the fundamental interactive capability we have in at least 3 of our interactive devices above. That system had a help mode (initiated by hitting the "?" key) that gave a list of some 20 different interactive modes you could start by hitting a particular key). This system was designed to help analyze astronomical absorption spectra (flux as a function of position in the direction of dispersion in the spectrograph) so there were modes to help find line positions, modes to help determine the continuum between lines, take equivalent widths of lines, calibrate the dispersion relation (wavelength as a function of position), zoom in x position (or wavelength), zoom in y position (flux), zoom in both coordinates, etc. At some point, I plan to write an application that reimplements this useful interactive system based on the currently existing fundamental PLplotinteractive device capabilities. Note, some higher-level interactive capability (zooming) has already been implemented for our tk device, but that would potentially interfere with implementation of higher level interactivity in applications like I have just described. So I definitely don't want to see, e.g., zooming capability implemented for all our interactive devices. On the other hand, I do want to see the fundamental interactive capability available for all our interactive devices so we do need a volunteer to add mouse button/key identification for -dev qtwidtet. I think we should also promote the fundamental interactive capabilities of our interactive devices a lot more since few (or none?) of our users seem to be aware of those. So I suggest a volunteer who has time/interest here modify example 1 to do just that. For example, it should be possible to implement zooming for that particular example by e.g., looking for the z key being hit (to initiate zooming), and then look at the position of the next two key strokes after that to identify the zooming box, then plot that zoomed area. And keep in zoom mode thereafter, until, say, the e key is hit to exit zooming mode. Making sure that capability worked for all our languages would probably be challenging (since we have never tried that before), but I think it would be well worth doing since we cannot anticipate what language someone will want to use to implement an interactive plotting application. That new capability for example 1 along with a DocBook section and some release notes advertising that new capability would be a good way to promote the current fundamental interactive capabilities of our interactive devices so that users would start using those in interactive applications they have developed for themselves. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); the Time Ephemerides project (timeephem.sf.net); PLplot scientific plotting software package (plplot.sf.net); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
