why doesn't wolfram alpha plot this graph?

Discussion:

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sobriquet

2024-11-16 19:22:05 UTC

Hi!

Recently someone shared this on discord:

https://www.desmos.com/calculator/rddekjhbtu

Somehow wolfram alpha seems unable to plot this?

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%7Csin%28x%29%2Biy%7C%29

sobriquet

2024-11-16 19:25:42 UTC

Permalink

Post by sobriquet
Hi!
https://www.desmos.com/calculator/rddekjhbtu
Somehow wolfram alpha seems unable to plot this?
https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%7Csin%28x%29%2Biy%7C%29

Uh... that wolfram link should actually be this one instead:

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

wugi

2024-11-18 00:16:31 UTC

Permalink

Post by sobriquet

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

It's in the tan( ) part. Desmos plots a train of circles surmounted by a
flattened sine. Wolfram refuses that one. Multifunction?

--
guido wugi

sobriquet

2024-11-18 13:22:00 UTC

Permalink

Post by wugi

Post by sobriquet

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

It's in the tan( ) part. Desmos plots a train of circles surmounted by a
flattened sine. Wolfram refuses that one. Multifunction?

Mod can cause issues I guess..
I can reduce the expression and still wolfram won't plot it, while
desmos does.

https://www.desmos.com/calculator/ryppmmdhsi

https://www.wolframalpha.com/input?i=plot+y%3Dx%7Cx%2Biy%7C

wugi

2024-11-18 15:28:44 UTC

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

It's in the tan( ) part. Desmos plots a train of circles surmounted by
a flattened sine. Wolfram refuses that one. Multifunction?

Mod can cause issues I guess..
I can reduce the expression and still wolfram won't plot it, while
desmos does.
https://www.desmos.com/calculator/ryppmmdhsi
https://www.wolframalpha.com/input?i=plot+y%3Dx%7Cx%2Biy%7C

It seems it can plot graphs with
y=Abs(f(x)) but not with
y=Abs(f(x,y)).
But it does with
Re() and Im()

--
guido wugi

wugi

2024-11-18 22:01:19 UTC

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

It's in the tan( ) part. Desmos plots a train of circles surmounted
by a flattened sine. Wolfram refuses that one. Multifunction?

Mod can cause issues I guess..
I can reduce the expression and still wolfram won't plot it, while
desmos does.
https://www.desmos.com/calculator/ryppmmdhsi
https://www.wolframalpha.com/input?i=plot+y%3Dx%7Cx%2Biy%7C

It seems it can plot graphs with
y=Abs(f(x)) but not with
y=Abs(f(x,y)).
But it does with
Re() and Im()

... while sqrt(xx-yy) isn't a problem:
https://www.wolframalpha.com/input?i=plot+y%3Dx*sqrt%28xx-yy%29

!!??

--
guido wugi

wugi

2024-11-18 22:09:24 UTC

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

It's in the tan( ) part. Desmos plots a train of circles surmounted
by a flattened sine. Wolfram refuses that one. Multifunction?

Mod can cause issues I guess..
I can reduce the expression and still wolfram won't plot it, while
desmos does.
https://www.desmos.com/calculator/ryppmmdhsi
https://www.wolframalpha.com/input?i=plot+y%3Dx%7Cx%2Biy%7C

It seems it can plot graphs with
y=Abs(f(x)) but not with
y=Abs(f(x,y)).
But it does with
Re() and Im()

https://www.wolframalpha.com/input?i=plot+y%3Dx*sqrt%28xx-yy%29
!!??

[rather (...+yy)]

And this one:
https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-sqrt%28%28sin%28x%29%29%5E2%2By%5E2%29

Complex mods or abss won't do.

--
guido wugi

Chris M. Thomasson

2024-11-18 23:07:22 UTC

Permalink

On 11/18/2024 2:09 PM, wugi wrote:
[...]

Try this one:

ParametricPlot[{(cos[t] + floor(sin[t]) * 2 + 1) * .5, sin[t] * .5}, {t,
0, 2*pi}]

Semi circle wave?

Loading Image...

sobriquet

2024-11-19 03:18:50 UTC

Permalink

Post by Chris M. Thomasson
[...]
ParametricPlot[{(cos[t] + floor(sin[t]) * 2 + 1) * .5, sin[t] * .5}, {t,
0, 2*pi}]
Semi circle wave?
https://i.ibb.co/gw8ZrQc/image.png

The 3D version of desmos is so helpful to provide insight when you try
to figure out what functions are doing exactly.

Loading Image...

I'm trying to create a parametric version of this one:

https://www.desmos.com/calculator/ayyjmdqykt

Chris M. Thomasson

2024-11-19 03:20:46 UTC

Permalink

Post by sobriquet

Post by Chris M. Thomasson
[...]
ParametricPlot[{(cos[t] + floor(sin[t]) * 2 + 1) * .5, sin[t] * .5},
{t, 0, 2*pi}]
Semi circle wave?
https://i.ibb.co/gw8ZrQc/image.png

The 3D version of desmos is so helpful to provide insight when you try
to figure out what functions are doing exactly.
https://i.imgur.com/XkjrSdK.png
https://www.desmos.com/calculator/ayyjmdqykt

Ohhh, that is damn nice! I am busy right now, but thanks for that one!
Excellent. Thanks.

sobriquet

2024-11-19 00:49:34 UTC

https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-%7Csin%28x%29%2Biy%7C%29%29

It's in the tan( ) part. Desmos plots a train of circles surmounted
by a flattened sine. Wolfram refuses that one. Multifunction?

Mod can cause issues I guess..
I can reduce the expression and still wolfram won't plot it, while
desmos does.
https://www.desmos.com/calculator/ryppmmdhsi
https://www.wolframalpha.com/input?i=plot+y%3Dx%7Cx%2Biy%7C

It seems it can plot graphs with
y=Abs(f(x)) but not with
y=Abs(f(x,y)).
But it does with
Re() and Im()

https://www.wolframalpha.com/input?i=plot+y%3Dx*sqrt%28xx-yy%29
!!??

[rather (...+yy)]
https://www.wolframalpha.com/input?i=plot+y%3Dsin%282x%29%2F2+tan%28%282pi%29%5E%281-sqrt%28%28sin%28x%29%29%5E2%2By%5E2%29
Complex mods or abss won't do.

Ah great.. that makes sense.

Yeah.. the +yy vs -yy had me confused a bit..

https://www.desmos.com/3d/es3qju0qem