Expected result πi Actual behaviour <p dir

confirmed in mate-calc 1.20.3 <a target="_blank" rel="noopener noref

It doesn't work in gnome-calculator 3.11.90 <p d

It seems to be related the function mp_ln_real in <co

Preferences -> Calculator -> Angle Units -> Radians <div class="snippet-c

ln(e^(i*π)) doesn't calculate about mate-calc HOT 6 CLOSED

mate-desktop commented on August 21, 2024

ln(e^(i*π)) doesn't calculate

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Comments (6)

sc0w commented on August 21, 2024

confirmed in mate-calc 1.20.3

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willysr commented on August 21, 2024

Confirmed in 1.22.0 as well

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sc0w commented on August 21, 2024

It doesn't work in gnome-calculator 3.11.90

It works in gnome-calculator 3.12.0

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sc0w commented on August 21, 2024

seems it was fixed for gnome-calculator with one of these commits, (or both):

Fix precision loss of ln(e^1) (fixes bug 711766)
https://gitlab.gnome.org/GNOME/gnome-calculator/commit/e1ba299acfe4cf6631de4d457b9451471171ee39

Use double instead of float for better precision ln (fixes bug 702817).
https://gitlab.gnome.org/GNOME/gnome-calculator/commit/6eb0f2b5e6df456a97a796b35d811376a69679e0

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sc0w commented on August 21, 2024

It seems to be related the function mp_ln_real in /src/mp.c

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rbuj commented on August 21, 2024

Preferences -> Calculator -> Angle Units -> Radians

e^(i*π) = cos(π) + sin(π)i = -1 + 0i = -1 [WORKS]
ln(-1) = ln(-(-1)) + πi = ln(1) + πi = 0 + πi = πi [WORKS]

Fails on parse.

(gdb) backtrace                                                                                                                                          
#0  0x000000000041f0c4 in mp_set_from_float (rx=<optimized out>, z=z@entry=0x7fffcd7e8060) at mp-convert.c:54
#1  0x000000000041df60 in mp_ln_real (x=x@entry=0x7fffcd7f1d20, z=z@entry=0x7fffcd7f5bc0) at mp.c:1256
#2  0x000000000041e31e in mp_ln (x=x@entry=0x7fffd0013bf0, z=z@entry=0x7fffd0011c90) at mp.c:1297
#3  0x00000000004206d6 in get_function (state=0x7fffd000fcd0, name=0x7fffd00015c0 "ln", x=0x7fffd0013bf0, z=0x7fffd0011c90) at mp-equation.c:173
#4  0x0000000000427962 in pf_apply_func (self=0x7fffd0004e10) at parserfunc.c:306
#5  0x0000000000429b1b in p_parse (state=state@entry=0x7fffd000fcd0) at parser.c:276
#6  0x0000000000421139 in mp_equation_parse (expression=expression@entry=0xd9ccc0 "ln(e^(i×π))", options=options@entry=0x7fffcd7f7be0, result=result@entry=0x7fffcd7f7c30, error_token=error_token@entry=0x7fffcd7f7bd8) at mp-equation.c:266
#7  0x0000000000415ec1 in parse (error_token=0x7fffcd7f7bd8, z=0x7fffcd7f7c30, text=<optimized out>, equation=0x4faa90) at math-equation.c:1184
#8  0x0000000000415ec1 in math_equation_solve_real (data=<optimized out>) at math-equation.c:1219
#9  0x00007ffff716f752 in  () at /lib64/libglib-2.0.so.0
#10 0x00007ffff6f975a2 in start_thread () at /lib64/libpthread.so.0
#11 0x00007ffff6ec4023 in clone () at /lib64/libc.so.6