Analysis applications, volume calculation – Mathematics Stack Exchange

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electrum – How can I troubleshoot whether an unconfirmed transaction that seems stuck is a problem on my end or just from high volume on mempool?

Never had transaction hang unconfirmed like this before. Granted its only been a few hours but it’s not like I skimped on fees either. I always choose the default electrum fee, but when it got stuck I doubled it using RBF to increase the fee.

But it’s still stuck!

How can I check whether I’m really in the queue being ignored because people are paying higher fees or if there’s something wrong I’m doing on my end?

Regenerating my wallet in electrum at least restored my pre-send balance. So at least I can see my coin even if there’s no movement on this transaction that I’d love to either cancel out of or see confirmed.

partition – Macbook Pro main volume not accessible – filesystem type FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF

Preface: I know there are lots of other questions about this on here, but they do not exactly match my situation and/or I do not have the technical knowledge to apply the answers to my situation. Thank you in advance for any help!

I have a Macbook Pro (Late 2011), running High Sierra. I partitioned the harddrive to install Linux. I later uninstalled Linux, and I seemingly did it in a bad way! My main volume now is unbootable, and it does not show up in the startup manager. I’m also not able to boot from Recovery, so to get to the terminal I’ve booted from a UBS flash drive with a MacOS installer on it.

I followed the steps from answers to similar questions on here, and I got to the step where I remove the volume with the gpt command, but then couldn’t get any further. So the main partition doesn’t show up on the diskutil list anymore (shown below).

Here is some relevant information from the terminal. Sorry for the awful alignment of these. If there’s a way to type is out in a more readable way here, I don’t know it. For convenience of viewing, I’ve also included photos of these outputs (below).

$ diskutil list

#: TYPE. NAME SIZE IDENTIFIER
0: GUID_partition_scheme – 750.2 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS – 650.0 MB disk0s3
3: Microsoft Basic Data – 74.3 GB disk0s4

gpt -r show disk0

gpt show: disk0: Suspicious MBR at sector 0
start size index contents
0 1 – MBR
1 1 – Pri GPT header
2 32 – Pri GPT table
34 6
40 409600 1 GPT part – C12A7328-F81F-BA4B-00A0C93EC93B
409640 1318255112 2 MBR part 218 (no contents because I removed this one)
1318664752 1269536 3 GPT part – 48465300-0000-11AA-AA11-00306543ECAC
1319934288 1712 – –
1319936000 145210938 4 GPT part – EBD0A0A2-B9E5-4433-B7C0-6886B72699C7
1465146938 2197 – –
1465149135 32 – Sec GPT table
1465149167 1 – Sec GPT header

output from diskutil list
output from got -r show disk0

The answer at this question has been the most helpful to me so far. However, I do not have an additional mac to do the hex dump that the answer calls for. If needed, I can borrow one from a friend, but I don’t own one.

Any help would be greatly appreciated!

plotting – Converting a 2d surface into a 3d volume

I have a 2d surface shown in the image below using ListPlot3D():

image
It is generated with one line of code:

ListPlot3D(RandomVariate(UniformDistribution(), {10,10}))    

Currently, it’s a ‘white noise’ surface, meaning the surface is more or less random between zero and one. I’d like to give this thickness (so I can ultimately 3d print it).

I’d like the remaining 5 sides to be flat, so that I’d end up with a “cube” with one surface jagged.

Is there an easy way to do this? Essentially just fill in everything below the surface?

Thanks!

❕NEWS – ETHEREUM DEX reaches a volume of almost 500 million in 24 hours | Proxies-free

As many of us already know, DEXs (decentralized exchangers) currently have a growing boom, comparable to the launch of ICOs in early 2017. Every day they gain ground over their centralized counterparties (CEX)
The trading volume on the Ethereum DEX network was close to 500 million dollars and so far in 2020, 13.5 billion dollars have been traded. In 2019 only 3 billion were traded.
This shows that decentralized finance takes hold every day because it offers more attractive user experiences coupled with unique business strategies.
Among the 10 DEX with the highest volume of commercialization in 24 hours we have:

1.- Uniswap with US $ 336,268,887 and 53.1% DEX market share
2.- 1inch exchange with US $ 61,018,685 and 9.6% DEX market share.
3.- Compound Finance exchange with US $ 51,856,692 and 8.2% DEX market share.
4.- Balancer exchange with 45,078,934 US $ and 7.1% DEX market share.
5.- Curve Finance exchange with 38,261,542 US $ US $ and 6.0% DEX market share.
6.- Kyber Network exchange with US $ 25,603,087 and 4.0% DEX market share.
7.- 0x Protocol with 17,362,009 US $ and 2.7% DEX market share.
8.- AirSwap exchange with US $ 11,627,362 and 1.8% DEX market share.
9.- Uniswap (v1) exchange with US $ 9,907,434 and 1.6% DEX market share.
10.- Tokenlon exchange 7,142,916 US $ and 1.1% DEX market share.

If we add up all the amounts, it gives us a sales volume of US $ 633,559,451. Apparently the amount announced by the news has already been exceeded.
So, pending with the tokens that are traded in the DEX to catch those economic waves that take us to areas of excellent profits, which in the end is what we all expect when we invest our money.

ag.algebraic geometry – Example of a computation of the volume of a subvariety in projective space $mathbb{P}^n$

Let us consider the projective space $mathbb{P}^n$ with the standard Fubini Study metric.

I searched all over the internet but I can’t find an example of a calculation of the volume for a projective subvariety $X subset mathbb{P}^n$ (we can assume it to be smooth of course).

For example given the projective plane $mathbb{P}^2$ with coordinates $(x,y,z)$ and the smooth conic $$C:(xy-z^2=0) subset mathbb{P}^2$$ does somebody know how to compute the Volume $textit{Vol}(C)$?
Or maybe a reference where a similar computation is carried out?
For simplicity we can assume that the ground field is $mathbb{C}$.

Thanks in advance.

riemannian geometry – Identify an ordered-eigenvalue simplex with tetrahedral dihedral angle $cos ^{-1}left(frac{1}{3}right)$ in volume, area formulas

Let us order the four eigenvalues ($lambda_1 geq lambda_2 geq lambda_3 geq lambda_4$, $Sigma_{i-1}^4 lambda_i=1$) of a Hermitian, trace-one, positive-definite $4 times 4$ matrix (a “two-qubit density matrix”, in quantum parlance). Those density matrices for which the inequality
$lambda_1-lambda_3 < 2 sqrt{lambda_2 lambda_4}$ holds are termed “absolutely separable” (that is, can not be entangled by any global unitary transformation).
In terms of the Hilbert-Schmidt probability distribution $9081072000 Pi_{j<k}^4 (lambda_j-lambda_k)^2$ on the simplex of ordered eigenvalues (HilbertSchmidt), the volume/probability of the absolutely separable states has been found to be (Evaluate Explicit)
begin{equation}
frac{29902415923}{497664}-frac{50274109}{512 sqrt{2}}-frac{3072529845 pi }{32768
sqrt{2}}+frac{1024176615 cos ^{-1}left(frac{1}{3}right)}{4096 sqrt{2}} approx 0.00365826
end{equation}

while the area/probability of the boundary absolutely separable states (the locus of $lambda_1-lambda_3 =2 sqrt{lambda_2 lambda_4}$ ) has been further shown to be (Confirm)
begin{equation}
-frac{837276448115}{663552}+frac{86031670725 pi }{32768 sqrt{2}}-frac{86031670725
cos ^{-1}left(frac{1}{3}right)}{16384 sqrt{2}} approx 0.15339,
end{equation}

where, notably, $cos ^{-1}left(frac{1}{3}right)$ is the dihedral angle of the regular tetrahedron.

Might these formulas provide any possible insight into the underlying geometry of the two-qubit absolutely separable states?

windows 10 – Why is my microphone volume so quiet?

A few weeks ago I installed Clownfish on my Huawei Matebook 13 running Windows 10 for a Zoom session, and then uninstalled it shortly after. I made sure all traces of the program were gone, including the audio drivers it installed.

Since then, my microphone has been barely picking up my voice. I’m sometimes told it has a terrible static noise louder than my voice (I’m only told this on certain platforms, I think due to more aggressive noise cancelling). Whether I’m using headphones with an in-line microphone or a headset with built-in microphone or just my computer’s microphone, my voice is almost inaudible over Zoom, Discord etc. I couldn’t tell you if it is any different in non-communication circumstances (eg. voice recording) as I have no idea how it originally was, but my voice sounds fine in voice recorder as far as I can tell. I’ve gone through all Windows settings, everything is at max volume. Images of other potentially meaningful settings:
communication settings,
advanced settings.

However, I’ve tried every configuration of these settings to no avail. Does anyone know what could be causing my problem?

windows – Extended Disk Volume

I had partitioned my 1TB Hard Drive for Dual booting my laptop. Since I don’t need the second OS anymore I wanted to extend the partition in Windows 10.

The process is fairly easy if the partition to the right is empty or unallocated. In my case, there is a partition known as Healthy(EFI System Partition) which does not allow me to extend the volume. I am unable to delete this EFI volume which stops me from extending my partition. The only option I get is Help.

Is there any way to delete this or shift(move) the partitions?

Here is a screenshot of my Disk Management