Sorry for a potentially stupid question.
I'm a researcher and I got the following comment on a manuscript which I need to address:
>Please report results to a reasonable number of digits that reflects accuracy of the measurement (e.g., 76% or 76.0% instead of 75.99%). I doubt any of these tests were large enough to offer four significant digits of precision.
How would I determine what level of precision the test was large enough to offer? The numbers are percentages, calculated from counts usually out of 5242 (so e.g. for 1500 out of 5242 I have written 28.62%). In the original draft I always used four significant figures.
Edit to add more information: I wrote a bioinformatics tool which processes an input file in a number of ways, then I have a series of tests to see if the processing was successful. Each test has a binary outcome, true or false, and I ran the tool on 5242 datasets (which I simulated). My percentages are the percentage of the 5242 which had a true versus a false outcome.
I've seen a lot of references to this HMPOR "sequel" on here before, mostly along the lines that it's considerably more difficult to get through, and finally curiosity has won out over cowardice. I'm now eighteen chapters in and enjoying it immensely!
I've just read a "bonus" chapter in which Fred, George and Neville have been in a car chase. I won't say any more than that here but it was great fun!
Looking forward to more, but trying to restrain myself and not devour the whole book in one go...
EDIT: Finished! And in a mere twelve days!
What exactly is the ritual that Harry came up with in Sig Dig? I've read the whole story once already but I think I missed that part.
Was wondering if there was and option (or maybe a mod) so that I could see exact or more precise amounts of items/electricity being produced. For example, if I produce ~1.1 GW of electricity, I'd like to see it as a more exact amount like 1.14 GW, 1.137 GW, etc.
What's the best way to specify precision and significant digits. I end up with these extra zeros in my queries and reports.
I have tried to specify by placing these two lines at the top of my ledger file:
D 1,000.00 USD
D 1.00 USD
For example, if I run the register command I have four extra zeroes.
$ ledger --version
Ledger 3.1.3-20190331
$ ledger --file ledger.dat register assets --period "this week" --sort "date" --anon
21-Sep-13 9d1287a0 39:8e4c:2d8259a:68abd52:20601b01 -165.000000 A -165.000000 A
21-Sep-14 4ed1c0e9 1d:f935:853f619:0ba0467:40efaa30 -1,171.460000 A -1,336.460000 A
42:fb4a:9b75393:90b7f7f:03851274 1,171.460000 A -165.000000 A
21-Sep-14 c37d8a32 4e:1f35:7af97fa:e869e10:1ba9a99a -788.220000 A -953.220000 A
21-Sep-17 9cc02b99 b4:b608:334ec2a:f53aec4:ef3e4ef1 -1,987.160000 A -2,940.380000 A
21-Sep-18 6136d3a4 7b:38fc:1f8d42c:d060fa7:8d5d7554 -107.000000 A -3,047.380000 AFinding: Any N with n least-significant 1 bits (in binary) rises to 3^n*(x+1)-1 where x is N shifted right n binary digits (i.e. x consists of upper bits of N minus lower n 1 bits).
Note: The formula was discovered empirically by u/g00berc0des and I believe I've proved it to be true for the general case (see below). I have no idea if this is a new or unique finding but it provides a useful shortcut for finding the initial peak of any number without iteration.
Example: Any number represented in binary as xxxx111 always rises three times (one (3x+1)/2 step for each LSB digit). We can directly calculate the top of this initial rise as 3^3(x+1)-1 or 27x+26.
Note: Since x is always even (its LSB is 0), the next step after the calculated rise will fall (i.e. divide by 2). Obviously, subsequent steps may rise above the calculated initial peak so this formula does not calculate the absolute peak of N's Collatz sequence.
Background: In another thread, I mentioned the (sort of) well-known fact that the least-significant 1 bits of N (in binary) determine how many rise steps start N's Collatz sequence. u/g00berc0des ingeniously determined a formula which provides a shortcut to calculate N's initial rise.
In the following table, I stepwise verify that u/g00berc0des formula works for all N with 1 to 4 LSBs and then prove (see rightmost column) that it works for the general case of n LSB 1 bits.
The rightmost column shows that every (3x+1)/2 step results in 3^Y*2^X*(x+1)-1 with Y increasing and X decreasing at each step until you've reached (Y=n,X=0) or u/g00berc0des formula 3^n*(x+1)-1
- Columns are examples of patterns of N
- Rows are Collatz steps for each pattern (Step 1 at the top to Step N at the bottom)
The middle part of this review contains moderate spoilers; skip to the end for a final judgement if you're deciding whether or not to read this work. The review as a whole contains spoilers for Harry Potter and the Methods of Rationality, but let's be honest, if you're reading this, you've probably read HPMOR already.
#Introduction
As someone who enjoyed Harry Potter and the Methods of Rationality, I was naturally eager to read more stories set in that world. Given the absence of an official epilogue, continuation fics are about the only way to get any HPMORe. However, the sheer volume of fan made sequels, AUs, and even doubly recursive fanfiction available put me off for a long time. A while back I got around to reading one of the more well-known ones, Significant Digits. The hub page on the author's site features a quote by Eliezer Yudkowsky himself proclaiming it to be 'The best HPMOR continuation fic'. Some digging produces a couple of reddit comments to back this up. Impressive, but unfortunately, reading those comments did not quite have the desired effect. Ah ha, I thought. Here is the reason why I don't have my HPMOR epilogue. If this why Yudkowsky canned his planned epilogue, it had better be good. Does it live up to expectations?
Well, it's complicated. First, an
#Overview
Significant Digits (~300,000 words) by Alexander Davis, of Anarchy is Hyperbole, is a recursive fanfiction of HPMOR. Set well after the end of HPMOR, with a college-aged Harry and Hermione, the main story explores the consequences of HPMOR's climax, namely Harry setting up a free hospital that can cure literally anything, but being effectively held prisoner in one secure location almost indefinitely, and Hermione being a superpowered unicorn heroine. A large portion of Significant Digits explores the wider wizarding world, both internationally recognized governments and shadowy secret cabals, and their reactions to these new developments.
In some ways, you could say that Significant Digits is to HPMOR as HPMOR is to the original Harry Potter. Its strengths build on what made HPMOR popular in the first place, while the things it doesn't get right remind me of the
... keep reading on reddit ➡
Hey! So I’m new here and another sub directed me here about questions regarding support, and I have a huge problem in regards to my xR.
So before anytime I’d set up an account the OS would always ask me if I wanted an auto generated strong password. This made life easy and secure. I stopped using faceID as I prefer the 4 digit pin. The enormous problem I have is the OS will not ask me or help me auto generate a strong password.
Because of all the data breaches, and my inability to figure out a solution my man made passwords all became comprised, and it’s been absolute hell it’s taken a major affect on my life negatively as I have over 80 security breaches.
Is there anyone that has a solution to where I can get my phone to go back to auto generating strong PW’s each and every time without having to use faceID? If anyone could help me it would honestly mean the world, as I can’t figure it out, and everything from my social to business account has been affected. Any help would be greatly appreciated.
Thank you and god bless!
Doing a new warranty registration portal ( web/SMS/ ..BUT mainly IVR phone) for owners to register their new products.
I have proposed that we reverse order the reference number. We have a 16 digit account/reference number we will use for lifetime of the customer ( with other validation / safekeeping of account)
I have asked that this reference number have the most significant digit increasing first . e.g. 0009, 1009, 2009, ...0109, 1109 . I think this will speed up IVR and web registration as the most significant changing digits will be read and entered first -instead of reading a 16 digit number that has rare changing digits every time.
Anyone on team thinks this is strange and surely will cause problems .
To me its a simple improvement that will speed up IVR and customer entry.
Thanks for the input folks - we are going to try this - with the aim that we speed up contact time on the call centre and limit misread digits. Thanks I learned of other useful things - making N digits significant - someone suggested better grouping and perhaps printing significant digits BIGGER so the customer alomost automatically sees them as significant.
Can someone tell me how to count a particular digit appears as an Least Significant Digit or Most Significant Digit in a particular column. Like:
MSD_1 means - percentage of time 1 appears as the Most significant digit of the data column
LSD_1 means - percentage of time 1 appears as the least significant digit of data column
https://preview.redd.it/nv2jbi83mml61.png?width=475&format=png&auto=webp&s=044f476095f2e5a6563e94423b73a9c67391ac2f
In the beginning I used hledger to track my bank accounts and credit cards and all was good. Inputs were to the cent and reports were to the cent.
Later I added stocks I held and their current values. Now inputs are coming in to the 1/100 of a cent ($0.0001). It doesn't bother me that hledger is tracking to this accuracy, but I would prefer that my reports be printed to the cent or dollar (or whatever seems most appropriate to me at the time).
I have been unable to find in the documentation a flag that sets the significant digits in the output (or set rounding to the nearest cent/dollar/etc). Am I overlooking something or is this not an available option.
Let's say you round 30,346 to 2 significant digits. It would become 30,000. Would the 0 after the 3 count as a significant digit? My textbook says it does, but I'm a little skeptical, as it is a trailing 0.
Any advice?
I remember (not the chapter) that they were trying to determine how much of.a brain was needed before the Killing Curse counted it alive. The narrator said that progress was slow, it's hard to hate fruit flies. Quirrel told Harry about the Killing Curse 2.0 - cast with indifference. Why couldn't they use that?
Does anyone know if the early episodes of Blaine Rogers' unfinished Significant Digits podcast are still available anywhere? SoundCloud only seems to be hosting the latest five.
>A group of Civil Engineers were at a conference being held in Central Australia. As part of the conference entertainment, they were taken on a tour of the famous rock, Uluru.
>
>"This rock", announced the guide, "is 50 000 004 years old."
>
>The engineers - always impressed by precision in measurement - were astounded.
>
>"How do you know the age of the rock so precisely?" asked one of the group.
>
>"Easy!", came the reply. "When I first came here, they told me it was 50 million years old. I've been working here for four years now."
This classic anecdote is one of the most commonly recited in high schools and colleges when it comes to determining the amount of significant digits.
Yet somehow, we see a ton of bad calculations that start of with assumptions with one or two significant digits and end up with answers of 16 significant digits.
A brief summery: In science the number "5.00" is distinctly different from the number "5," in that the former is 100 times more precise than the latter. The number 5 can range between [4.5, 5.5), i.e. 4.5 is rounded up to 5 and 5.499 is rounded down to 5. While 5.00 is in the range [4.995, 5.005).
Suppose we've measured 3 values, A, B and C, and we're about to determine D according to the formula (A + B) / C = D.
A = 1.0 (2 significant digits)
B = 100 ± 0.5 (3 significant digits)
C = 3 (1 significant digit)
If we calculate this we get that D = (1 + 100) / 3 = 36.666...7, but according scientific notation this is wrong. Because the decimal expansion is indicative of infinite precision. So what's the actual value of D? It's 40, because the lowest significant number we use in the calculation is 1, and 36.66... is rounded up to 40.
Because the actual range is (0.5 + 99.5 / ⌊3.5⌋) to ( ⌊1.05⌋ + 100.5 / 2.5 ) or 28.57... to 41.25.
But isn't 36 closer than 40 to the middle of the range? In this case it is, that doesn't mean it's necessarily closer to the "accurate value," but most importantly it implies an inaccurate precision in the measurement (or estimation).
I have an analog input (UV sensor) and I want to send it to 2x 7-segment LED displays via some BCD 74LS47 latches.
When the calculated value from the input is less than 10.0, I want to display it to one decimal place, rounded properly. So 8.85 becomes 8.9, and 9.91 is 9.9. 9.95 should however display as 10.
Greater than or equal to 10, it stays at 2SD but is truncated, so 10.1 displays as 10, 11.7 displays as 11.
My code for proof of concept of the display logic is below, but it fails when the rounding isn't exact- i=220 in my test code for example. The code runs through a few key numbers to help me check my logic, and then stops. Any help appreciated.
E: This is on a nano, so I don't have room to load too many libraries.
int i = 0; // test number for iterating the logic
int MSD = 0; // Most Significant Digit
int LSD = 0; // Least Significant Digit
int RMD = 0; // Remainder, used for rounding
char decimal; // position of decimal indicator
int leftDigit;
bool leftDecimal;
int rightDigit;
bool rightDecimal;
const float k1 = 5.0*1000*0.0105/1023.0; // uvSensorValue to UV Index direct conversion multiplier (1023 steps)
const float c1 = -1.3324; // y-offset
int uvSensorValue = i; // UV Sensor raw value
float uvIndex = 0; // Sensor Value converted to standard UV Index
int stdUVIndex = 0;
float flDisplay = 0.0; // setting up the display
void setup() {
Serial.begin(9600);
Serial.println("");
Serial.println("INT\tFLOAT\tMSD\tLSD\tRMD\tDisplay\tDecimal\tResult");
for (i = 215; i <245; i++) {
uvSensorValue = i;
uvIndex = k1 * uvSensorValue + c1; // convert analogue read directly to UV Index
if (uvIndex < 0) {
uvIndex = 0;
}
MSD = int(uvIndex);
LSD = int(uvIndex * 10) - (MSD * 10);
RMD = int(uvIndex * 100)- (MSD * 100) - (LSD * 10);
// round Least Significant Digit
if (RMD >= 5) {
LSD += 1;
}
flDisplay = float(MSD) + float(LSD/10.0); // crosschecking for debugging
if ((MSD + LSD/10) < 10) {
decimal = 'L';
}
else {
decimal = 'R';
} // yes I know I can collapse this into the code directly below :-)
if (decimal == 'L') {
leftDigit = MSD;
leftDecimal = HIGH;
rightDigit = LSD;
rightDecimal = LOW;
}
else {
LSD = MSD % 10;
MSD = (MSD - LSD)/10;
leftDigit = MSD;
leftDecimal = LOW;
rightDigit = LSD;
rightDecimal = HIGH;
}
// output results
Serial.print(uvSensorValue);
Serial.print("\t");
`Serial
... keep reading on reddit ➡Can anybody teach me about significant figures real quick? Like some zeroes after the decimal place and stuff? Would help me too if you could tell me what answer you got for question 35 c.
https://preview.redd.it/p46y2dajwso51.png?width=526&format=png&auto=webp&s=b8bdd9e1bb7a07e2a326d405fdef85654229ec2e
Hi,
So In my workflow, daily I need eBay to spit out an excel file for me including information about buyers, addresses, prices, and shipping tracking numbers. I export an Excel file from eBay and it gets me the information I need, that I then copy and paste into a Google Sheets file of mine. When this Excel file is given to me I am given a tracking number shown like this:
9.40551E+21
I click the cell and format it from "General" to "Number" and then it converts it to this:
940551820545650000000
I need it to show instead the entire number with all the relevant numbers of Tracking number like this:
9405518205456526515012
Anyone know how and if this can be accomplished? I feel like those last numbers are forever lost due to how the Excel file is originally exported to me... but maybe there's a way to get those numbers I need? Any help would be much appreciated, thanks.
Does anyone know if the early episodes of Blaine Rogers' unfinished Significant Digits podcast are still available anywhere? SoundCloud only seems to be hosting the latest five.
