florinandrei
florinandrei t1_jddgxbj wrote
Reply to comment by CrustalTrudger in Does the metal in the solid core of a rocky planet have any special properties? by VillagerNo4
> the core is predominantly iron with a small amount of nickel (constrained to being around 5%)
What is the constraint?
florinandrei t1_jd6bwq6 wrote
Reply to comment by Dr-Luemmler in Can a single atom be determined to be in any particular phase of matter? by Zalack
It definitely does have a kinetic energy.
The only thing is - when you go from kinetic energy to temperature, you run into all sorts of trouble if you do it for single entities.
Temperature is an inherently collective measure. If it's single particles, stick to kinetic energy.
What is the "temperature" of this marble I'm throwing? ;) (not the temperature of the glass, but the "temperature" of the marble as a single particle with some kinetic energy)
florinandrei t1_jd6br1i wrote
Reply to comment by OPossumHamburger in Can a single atom be determined to be in any particular phase of matter? by Zalack
> they exhibit different physical properties including changes in electrical conductance
Of course they do. I'm just saying - the borders between them are far more fuzzy than most people imagine.
E.g. consider the changes that occur in tar or pitch when cooled from the boiling point of water to the boiling point of nitrogen. It's liquid at one end. It's solid at the other. The changes are smooth, without any sharp transitions.
florinandrei t1_jd4ubra wrote
Reply to comment by Zalack in Can a single atom be determined to be in any particular phase of matter? by Zalack
Technically, you can associate a temperature to the velocity of the atom measured relative to the container, and therefore obtain a "temperature" for that atom. But a lot of concepts become quite strained when you reduce things to single atoms, and temperature is one of them. A single atom does not have a temperature in the normal sense.
To your initial question: the phases of matter are only defined for molecular or atomic collectives. Single molecules or atoms do not have a clearly defined phase of aggregation. Even for large molecular collectives it is not always clear whether they are solid, liquid, or gas. For example, on geologic time scales, even some "solids" can flow.
The phases of matter are more like convenience concepts. We use them to simplify discussions that would otherwise be complex. There's nothing fundamental about them. Do not get stuck in rigid categorizations there, because there's no point in doing that.
florinandrei OP t1_jb7pefb wrote
Reply to comment by Mediocre-Bullfrog686 in [D] The MMSegmentation library from OpenMMLab appears to return the wrong results when computing basic image segmentation metrics such as the Jaccard index (IoU - intersection-over-union). It appears to compute recall (sensitivity) instead of IoU, which artificially inflates the performance metrics. by florinandrei
> Isn't this what the ignore_index is doing?
No, it is not.
Let me repeat: ignore_index
cuts holes in both the ground truth label frames, and in the prediction frames coming out of the model. Any pixels in those holes are ignored.
This includes pixels in the predictions from the model. You are ignoring chunks of the model's output.
> How else should we exclude them from the average metric?
By not computing metrics for that pixel value.
average_metric = sum(metric_index1 + metric_index2 + ... + metric_indexN) / N
Simply do not include it in the sum, and then just divide by N-1 instead.
What you are doing is not equivalent to that. What you are doing is: you discard pixels from both label frame and prediction frame based on the shape of some regions in the label frame alone. That makes no sense. Whatever the model's predictions happen to be in those holes, they are ignored even if they have pixel values different from ignore_index
.
You are ignoring all the model's predictions in those holes, regardless of their pixel values.
You are discarding pixels from the model's output even if they have values different from ignore_index
.
florinandrei OP t1_jb7cujz wrote
Reply to comment by Mediocre-Bullfrog686 in [D] The MMSegmentation library from OpenMMLab appears to return the wrong results when computing basic image segmentation metrics such as the Jaccard index (IoU - intersection-over-union). It appears to compute recall (sensitivity) instead of IoU, which artificially inflates the performance metrics. by florinandrei
The problem is: the current algorithm cuts holes in the prediction frames, based on ignore_index
in the label frames.
Any pixels in the label frames equal to ignore_index
will cause pixels in both label frames and prediction frames to be completely ignored from calculations. If some predicted mask pixels fall into those areas, they will be excluded from all calculations. This is the issue that needs to be addressed.
You cannot exclude pixels from the predicted frames based on pixel values in the label frames.
If there is some index you want to ignore altogether, because you are not sure about the quality of the labels, it is best to just exclude it from the calculation of the average metric.
If some users set ignore_index
to the value of the background pixels, that will cut very large holes in everything, therefore discarding a lot of pixels from performance evaluation, and will severely skew the results.
Submitted by florinandrei t3_11kbuzq in MachineLearning
florinandrei t1_j9k5yda wrote
Reply to comment by mcjasonb in I turned my 6XX into a weighted blanket by GHOSTVIPERZ28
Beach balls /s
florinandrei t1_j696cef wrote
Reply to comment by [deleted] in What are the wooden cups called? by [deleted]
The sound would change tremendously, which is why this is not done.
florinandrei t1_j5ioydq wrote
Reply to comment by DarkPasta in 2 mafia members are walking through the woods, late at night by awesomeness1024
According to the Mass Effect trilogy, they will still have a version of this joke even in 2185 AD. Except it's about two alien races.
florinandrei t1_j2ff0l2 wrote
Reply to comment by HedgehogRoutine2695 in Ohm My Lord by ZevireTees
It only works when the signal is very strong, and it's an AM thing.
I've done this as a kid. There was a powerful AM station nearby, enough signal for listening in headphones. Using a huge wire antenna, good ground connection, and an output transformer, I was actually able to feed just barely enough signal in a small speaker. Placing the speaker in a small transistor radio box (like a DIY speaker box) made it audible in my room at a soft, but decent level.
There were no batteries in the schematic. All the energy came from the radio station. Since only one strong station was in the area, I didn't even need an LC frequency filter - a germanium diode was the only real component besides the headphones (or speaker + transformer). One side of a germanium transistor also works instead of a diode. Silicon diodes / transistors don't work.
The signal was plenty for comfortable listening in headphones. I was able to even use metallic rain gutters as an antenna, and my hand as a "ground connection" and it still worked okay. I could impress my friends by touching one wire to the rain gutters, and AM radio would play in the headphones.
High impedance headphones worked better. For the speaker, the transformer basically was just an impedance adapter - speakers have low impedance, but the schematic required high impedance for best results.
Here's the schematic for headphones:
Replace the headphones with transformer + speaker if you wish, but don't expect a lot of volume even in the best case.
If there is no strong AM station nearby, then it will not work at all.
General info and more complex schematics:
florinandrei t1_ivg39sj wrote
Reply to comment by emptyvasudevan in I heard God by emptyvasudevan
> I heard God
And He was like: "I see here lust and greed, and you're triggering other people's envy. Watch yourself there, buddy!" /s
florinandrei t1_iue6tt7 wrote
Reply to comment by tlst9999 in The Discovery that Lemons Cure Scurvy Caused the Formation of the Sicilian Mafia by agreea
Yeah, the mafia state is bad. Except for the mafiosi.
florinandrei t1_it0fgmz wrote
Reply to comment by wiggan1989 in When times are tough, my listening corner always brings a smile to my face. by wiggan1989
> I just feel lost in the music.
Good headphones tend to do that to you. :)
Enjoy your very nice listening corner!
florinandrei t1_iquc0v7 wrote
Reply to comment by Even_Information4853 in [D] Types of Machine Learning Papers by Lost-Parfait568
Who is in the bottom-left corner?
florinandrei t1_jdix80n wrote
Reply to comment by number1dork in What happened to the old COVID variants, like Delta? Could they come back? by number1dork
Yes. The newer variants have won the Darwinian struggle against the old variants. The old variants have been outcompeted.