This is the question:
Determine if the Hamming codes (15,10), (14,10) and (13,10) can correct a single error (SEC), detect a single error (SED) or detect double bit errors (DED).
I do know how Hamming distance work and how you can detect an error if you have the data-word that you want to transmit. But I don't know how to do it without the data-word.
Only for SEC which has the formula:
2^m > m+k+1
where
m = check bits
k = data bits
But is the any formulas for SED and DED? I have searched google all day long without any success.
I learned how to solve it checks the Hamming codes through this Youtube clip. there is no effective way. wish there was a faster way to solve the problem.
https://www.youtube.com/watch?v=JAMLuxdHH8o
This is not responding properly to the question because I know what the user
"user3314356" needs, but I could not comment because I did not have 50 reputation points!.
Related
I am trying to calculate a price based on rates. If the number is $20,000 or below, there is a flat rate of $700. If the number is between 20,001.01 and $50,000, the rate is 3.5% of the number. The rates continue to lower as the numbers go up. I can get Google Sheets to populate the box with $700 if it is below $20,000 but I can't seem to make it do the multiplication for me. The cell just shows C4*.035
I want it to multiply the number shown in the C4 square by the percentage listed.
Here is the code as it currently sits:
=if(AND(C4<=20000),"700",IF(AND(C4>=20000.01,C4<=50000),"C4*.035", IF(AND(C4>=50000.01,C4<=100000),"C4*.0325", IF(AND(C4>=100000.01),"C4*.03"))))
Note, I know nothing about coding so I apologize if it is sloppy or doesn't make sense. I tried to copy and format based on an example that was semi similar to mine.
try:
=IF(C4<=20000, 700,
IF(AND(C4>=20000.01, C4<=50000), C4*0.035,
IF(AND(C4>=50000.01, C4<=100000), C4*0.0325,
IF(AND(C4>=100000.01), C4*0.03))))
As BigBen noticed in his comment - there's a mistake in your formula. You should not use " " around the formula if you don't want it to be read as a string.
Actually more clean solution is using IFS formula for this task.
=ifs(C4<=20000,700,
C4<=50000,C4*0.035,
C4<=100000,C4*0.0325,
C4>100000,C4*0.03)
In the creation of a SsaSpikeEstimator instance by the DetectSpikeBySsa method, there is a parameter called pvalueHistoryLength - could anybody please help me understand, for any given time series with X points, which is the optimal value for this parameter?
I got similar issue, when I try to read the paper, https://arxiv.org/pdf/1206.6910.pdf, I notice one paragraph
Also, simulations and theory (Golyandina, 2010) show that it is
better to choose window length L smaller than half of the time series length
N. One of the recommended values is N/3.
Maybe that's why in the ML.Net Power Anomaly example, the value is chosen to be 30 for the 90 points dataset.
Iam working on a real time data acquisition. In that I should send a string of ASCII characters in order to initiate the communication between the device and the laptop. This is the scenario.
Coming to the point, I want to know how to manually calculate the CRC for the following sequence 16,2,71,16,3,using CCITT polynomial i.e 0x1021.
I used online calculator for calculating the CRC using the following link.
http://www.lammertbies.nl/comm/info/crc-calculation.html
And now since that I know the values obtained in the online calculations and I am planning to manually verify them.Please help me with the issue if anyone is aware of the method used to calculate CRC.
Any help is appreciated.
Tnaks in advance.
I have been scouring the internet for quite some time now, trying to find a simple, intuitive, and fast way to approximate a 2nd degree polynomial using 5 data points.
I am using VC++ 2008.
I have come across many libraries, such as cminipack, cmpfit, lmfit, etc... but none of them seem very intuitive and I have had a hard time implementing the code.
Ultimately I have a set of discrete values put in a 1D array, and I am trying to find the 'virtual max point' by curve fitting the data and then finding the max point of that data at a non-integer value (where an integer value would be the highest accuracy just looking at the array).
Anyway, if someone has done something similar to this, and can point me to the package they used, and maybe a simple implementation of the package, that would be great!
I am happy to provide some test data and graphs to show you what kind of stuff I'm working with, but I feel my request is pretty straightforward. Thank you so much.
EDIT: Here is the code I wrote which works!
http://pastebin.com/tUvKmGPn
change size to change how many inputs are used
0 0
1 1
2 4
4 16
7 49
a: 1 b: 0 c: 0
Press any key to continue . . .
Thanks for the help!
Assuming that you want to fit a standard parabola of the form
y = ax^2 + bx + c
to your 5 data points, then all you will need is to solve a 3 x 3 matrix equation. Take a look at this example http://www.personal.psu.edu/jhm/f90/lectures/lsq2.html - it works through the same problem you seem to be describing (only using more data points). If you have a basic grasp of calculus and are able to invert a 3x3 matrix (or something nicer numerically - which I am guessing you do given you refer specifically to SVD in your question title) then this example will clarify what you need to do.
Look at this Wikipedia page on Poynomial Regression
Sorry to ask a similar question to the one i asked before (FFT Problem (Returns random results)), but i've looked up pitch detection and autocorrelation and have found some code for pitch detection using autocorrelation.
Im trying to do pitch detection of a users singing. Problem is, it keeps returning random results. I've got some code from http://code.google.com/p/yaalp/ which i've converted to C++ and modified (below). My sample rate is 2048, and data size is 1024. I'm detecting pitch of both a sine wave and mic input. The frequency of the sine wave is 726.0, and its detecting it to be 722.950820 (which im ok with), but its detecting the pitch of the mic as a random number from around 100 to around 1050.
I'm now using a High pass filter to remove the DC offset, but it's not working. Am i doing it right, and if so, what else can i do to fix it? Any help would be greatly appreciated!
(Fixed)
Thanks,
Niall.
Edit: Changed the code to implement a high pass filter with a cutoff of 30hz (from What Are High-Pass and Low-Pass Filters?, can anyone tell me how to convert the low-pass filter using convolution to a high-pass one?) but it's still returning random results. Plugging it into a VST host and using VST plugins to compare spectrums isn't an option to me unfortunately.
Edit: Fixed, thanks for everyones help, but I never got it to work, now using new code.
I am no sound expert, but if you are sampling with 44100 (I guess samples per second) and use 1024 datapoints. You are working with about 1/40th of a second worth of data. I doesn't surprise me that the current pitch varies a lot, depending on which piece you pick. If you want to find the average or main pitch of a voice, I'd expect to need about 1second worth of data.
At 44.1 kHz sampling frequency, 1024 samples is only a little bit over 23 ms worth of data. Isn't it possible that this is simply insufficient data in order to compute the pitch of a human singer?
I mean, the sound I can make that lasts for 23 ms is probably not something I have a lot of pitch-control over; I would expect this kind of measurement to be done over slighly longer periods of time.
The problem is in your findBestCandidates() function:
Inside this function you access the 'inputs' array from 0 up to 'length - 1'.
When you call this function inside detectPitchCalculation() function 'inputs' is 'results' and 'length' is 'nHiPeriodInSamples'.
But 'results' is only allocated and filled up to 'nHiPeriodInSamples - nLowPeriodInSamples - 1'.
So if 'nLowPeriodInSamples' is greater 0 you access unallocated and random memory inside the findBestCandidates() function!
EDIT:
Another bug is that you fill each 'nResolution' entry of the 'results' array in detectPitchCalculation() function but access each entry in the findBestCandidates() function (via the 'inputs' argument). But since you call detectPitchCalculation() with a 'nResolution=1' this does not explain your specific problem...so I will look a little bit more. But it would definitely a problem if you call it with higher resolutions.
I don't see the problem in you code, but I'm no good in C. But I'd try the following to find the problem:
run with data where the result in known, e.g. with sin(x) as input
run it with small data size (e.g. 2)
Compare the results with known correct ones. You should be able to find those on the internet, or do them by hand.
If random means: same input, different output, you most probably have some bug in the initialisation of variables. Use a debugger and known input to check, that all variables, especially all elements of arrays are properly initialized.