SUMMARY STEPS TO REPRODUCE 1. File -> Open Example, choose the Lorenz example 2. Press 'Evaluate Worksheet' OBSERVED RESULT the plot in the Lorenz example disappears EXPECTED RESULT the plot remaining the same (as it was the case in the past) SOFTWARE/OS VERSIONS Linux/KDE Plasma: Ubuntu 18.04.2 (available in About System) KDE Plasma Version: N/A (irrelevant, but) (Unity) KDE Frameworks Version: (irrelevant, but) any from v5.44.0 backported to, to v5.58.0 (backported) Qt Version: (less relevant, but) v5.9.5 backported to, or any released up to date ADDITIONAL INFORMATION the latest compiled Cantor sources as of 3 June
It appears that *only* the Lorenz example is affected, octave_examples_{2d,3d}_plots.cws, as well as Maxima's examples show their respective plots.
This is something wrong with `view` command in Octave. I had checked the output .eps file: there is the plot inside it, but with a lot of empty space on the left of the plot (see atachment below). Cantor show a part of result .eps (because of too big width) file and this is a left empty part. Without `view` all works as expected.
Created attachment 120599 [details] Strange gnuplot output
Yes, indeed, removing that line with `view` has brought the plot back to my screen. Interesting to know that the white space to the left hid behind it.
UPDATE: 1. Remove the line with `view` 2. Press 'Evaluate Worksheet' # should be OK 3. Restart the backend # should be OK 4. Press 'Evaluate Worksheet' again # Segfault: Thread 1 "cantor" received signal SIGSEGV, Segmentation fault. 0x00007ffff7cf6062 in Cantor::TextResult::plain() () from /usr/lib/x86_64-linux-gnu/libcantorlibs.so.21 ─── Assembly ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 0x00007ffff7cf6058 ? mov %rdi,%rax 0x00007ffff7cf605b ? mov 0x8(%rdx),%rcx 0x00007ffff7cf605f ? mov %rcx,(%rdi) 0x00007ffff7cf6062 ? mov (%rcx),%esi 0x00007ffff7cf6064 ? add $0x1,%esi 0x00007ffff7cf6067 ? cmp $0x1,%esi 0x00007ffff7cf606a ? ja 0x7ffff7cf6070 <_ZN6Cantor10TextResult5plainEv+32> ─── Expressions ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── ─── History ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── ─── Memory ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── ─── Registers ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── rax 0x00007fffffffbd18 rbx 0x00007fffffffbd18 rcx 0x0000000000000000 rdx 0x0000000000e3b050 rsi 0x000000000099c9a0 rdi 0x00007fffffffbd18 rbp 0x00007fffffffbeb0 rsp 0x00007fffffffbce8 r8 0x000000000099c9a0 r9 0x0000000000000001 r10 0x0000000000000002 r11 0x0000000000000000 r12 0x0000000000dfcdb0 r13 0x0000000000dfcdb0 r14 0x00007fffcf3975c0 r15 0x00007ffff67c11f9 rip 0x00007ffff7cf6062 eflags [ PF ZF IF RF ] cs 0x00000033 ss 0x0000002b ds 0x00000000 es 0x00000000 fs 0x00000000 gs 0x00000000 ─── Source ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── ─── Stack ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── [0] from 0x00007ffff7cf6062 in Cantor::TextResult::plain() (no arguments) [1] from 0x00007fffcf3aacb6 (no arguments) [+] ─── Threads ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── [6] id 10392 name cantor:disk$0 from 0x00007ffff5c6f3bb in futex_wait_cancelable+27 at ../sysdeps/unix/sysv/linux/futex-internal.h:88 [5] id 10389 name QDBusConnection from 0x00007ffff5d98ba9 in __GI___poll+73 at ../sysdeps/unix/sysv/linux/poll.c:29 [4] id 10388 name gdbus from 0x00007ffff5d98ba9 in __GI___poll+73 at ../sysdeps/unix/sysv/linux/poll.c:29 [3] id 10387 name gmain from 0x00007ffff5d98ba9 in __GI___poll+73 at ../sysdeps/unix/sysv/linux/poll.c:29 [2] id 10386 name QXcbEventReader from 0x00007ffff5d98ba9 in __GI___poll+73 at ../sysdeps/unix/sysv/linux/poll.c:29 [1] id 10382 name cantor from 0x00007ffff7cf6062 in Cantor::TextResult::plain() ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
(In reply to vialav from comment #5) > UPDATE: > 1. Remove the line with `view` > 2. Press 'Evaluate Worksheet' # should be OK > 3. Restart the backend # should be OK > 4. Press 'Evaluate Worksheet' again # Segfault: > > Thread 1 "cantor" received signal SIGSEGV, Segmentation fault. Thanks, I had create Bug 408351 for this.
*** Bug 421229 has been marked as a duplicate of this bug. ***
This problem hasn't been reproduced on Ubuntu 20.04 with Octave 5.2.0 and Gnuplot 5.2 (patchlevel 8). So, at least, in modern Ubuntu/Octave this problem have gone. I think, this is enough evidence for confirming, that the problem origin is Octave itself, because I have build Cantor before and after my OS migration from 19.04 to 20.04 (it have took only few days and for testing I have build some sourcs) - and the problem gone after migration. So I mark this problem as resolved with upstream reason - looks like this Octave problem resolved in modern Octave versions (or maybe this is gnuplot problem, which used by Octave for graphics - I don't sure). And I will increase recommended Octave version to 5.2.0.