From 7b6482872ec06317028bacf6cb694a479b942d56 Mon Sep 17 00:00:00 2001 From: Hans-Christoph Steiner Date: Fri, 22 Aug 2003 00:20:54 +0000 Subject: added 0.37 version from pddp_referencesfiles.zip svn path=/trunk/; revision=890 --- doc/pddp/help-realtime.pd | 108 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 doc/pddp/help-realtime.pd (limited to 'doc/pddp/help-realtime.pd') diff --git a/doc/pddp/help-realtime.pd b/doc/pddp/help-realtime.pd new file mode 100644 index 00000000..daff3e33 --- /dev/null +++ b/doc/pddp/help-realtime.pd @@ -0,0 +1,108 @@ +#N canvas 64 358 939 645 10; +#X msg 43 113 bang; +#X msg 18 91 bang; +#X floatatom 18 157 0 0 0; +#X text 90 159 Output is in milliseconds; +#X text 53 91 Click here to start or reset; +#X obj 52 545 time_measurements; +#X obj 52 441 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 +-1; +#X floatatom 17 572 0 0 0; +#X floatatom 108 585 0 0 0; +#X floatatom 175 573 0 0 0; +#X text 9 357 In the example below \, I've created an abstraction which +will force each of PD's stop-watches \, [timer] [cputime] and [realtime] +to measure various processes and report the elapsed time. Click on +each [bng] to begin the process and wait for the results. Notice the +discrepancies in the results.; +#X text 15 587 Logical Time; +#X text 173 587 Real Time; +#X text 107 601 CPU Time; +#X obj 67 477 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 +-1; +#X text 72 435 1 Measures elapsed time between two "bangs" from a [trigger] +object.; +#X text 87 469 2 Measures the amount of time PD requires to turn on +DSP and start an oscillator.; +#X obj 445 484 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 +-1; +#X obj 445 17 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 +-1; +#X text 472 36 WHY THE DISCREPANCIES BETWEEN CLOCKS?; +#X text 475 59 In a fantasy world \, computers could exist somehow +beyond the restrictions of time and digital computation could be performed +in ZERO time. However \, that is not the case. Instead \, every process +within PD and within your operating system requires at least a few +nanoseconds of your CPU's time.; +#X obj 111 509 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 +-1; +#X text 476 144 The [timer] object is like a clock that is not constrained +to the regular laws of physics and the universal space-time continuum. +It reports "time" measurements as only PD can see them!; +#X text 477 204 The [cputime] object is like a clock that measures +how much time your CPU actually required to carry out your request. +Keep in mind however that your CPU is busy doing many things simoultaneously +\, so even though a process might take 5 minutes to complete \, your +CPU does not pay full attention to that process for the entire 5 minutes. +Instead \, it simply begins the process \, then refers back to that +process from time to time until the it is complete. In other cases +\, your CPU might require a full 5 minutes while PD might report that +merely a few milliseconds have passed. This type of discrepancy depends +heavily on your computer's hardware and the type of processing it is +performing.; +#X text 478 368 The [realtime] object is as much like your own wrist +watch as PD can possibly manage. It measures time according to your +operating system's internal clock.; +#N canvas 0 0 454 304 related_objects_from_other_libraries 0; +#X text 27 63 These objects are offered in PD only if you have downloaded +and properly installed the appropriate library. These objects may or +may not exist in a single library.; +#X text 26 112 The best places to find information about PD's libraries +is:; +#X text 23 134 www.pure-data.org and click on "Downloads" then "Software" +; +#X text 25 149 or; +#X text 25 164 iem.kug.ac.at/pdb/; +#X obj 44 24 t3_timer; +#X text 469 589 This document was updated for PD version 0.35 test +26 by Dave Sabine as part of a project called pddp proposed by Krzysztof +Czaja to build comprehensive documentation for PD.; +#X restore 505 476 pd related_objects_from_other_libraries; +#X text 309 580 This document was updated for PD version 0.35 test +28 by Dave Sabine as part of a project called pddp proposed by Krzysztof +Czaja to build comprehensive documentation for PD.; +#X obj 607 445 metro; +#X text 504 422 RELATED OBJECTS; +#X obj 504 446 cputime; +#X text 132 501 3 Measures the amount of time PD requires count to +three...please wait for approximately 3 seconds.; +#X obj 25 15 realtime; +#X text 83 15 -- ask Operating System for elasped real time; +#X text 13 44 The [realtime] object measures elapsed "real" time as +measured by your operating system.; +#X obj 18 135 realtime; +#X text 81 114 Click here to get elapsed real time. Click again...and +again...to see periodic measurements from the start or reset time. +; +#X text 11 185 [realtime] works like essentially like a stop-watch. +Once it starts \, you can continue to "poll" [realtime] to view the +elapsed time.; +#X text 11 232 The odd aspect about comparing [realtime] to a stop-watch +is that a stop-watch can be stopped! [realtime] can only be started +or reset. It cannot be stopped.; +#X text 9 282 As stated above \, [realtime] measures "real" or actual +time. This value may be slightly different that CPU time or "logical" +time. PD offers two objects which measure CPU time and "logical" time. +See the reference documents for those objects for more information. +; +#X obj 562 445 timer; +#X connect 0 0 34 1; +#X connect 1 0 34 0; +#X connect 5 0 7 0; +#X connect 5 1 8 0; +#X connect 5 2 9 0; +#X connect 6 0 5 0; +#X connect 14 0 5 1; +#X connect 18 0 17 0; +#X connect 21 0 5 2; +#X connect 34 0 2 0; -- cgit v1.2.1