Community Profile

# Geoff

Attivo dal 2012

I use MATLAB for small jobs and C++ for real jobs.
Professional Interests: Problem solving

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HOW CAN I CALCULATE THE SIGNAL TO NOISE RATIO(SNR) OF A CHIRP SIGNAL
From Wikipedia: http://en.wikipedia.org/wiki/Signal-to-noise_ratio NR = Psignal / Pnoise = (Asignal / Anoise)^2 Where P is powe...

quasi 3 anni fa | 0

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Help with proper parfor
You can't write to a parallel-segmented matrix in the inner loop. Try this: parfor i=1:r col = zeros(n,1); f...

oltre 11 anni fa | 0

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How can I import a .txt file correctly using textscan?
The way to have the most control over a line-based txt file import is to read it one line at a time: while !feof(fid) ...

oltre 11 anni fa | 1

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Script adapted into a funtion Function not returning equal values
Floating point precision errors. If you need to test for zero, then test for something like: if abs(value) < 1e-5 10^-5 ...

oltre 11 anni fa | 0

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time to number conversion
From memory, if you use |datenum| to just get the time with no date, it doesn't return a number between 0 and 1. But you can ge...

oltre 11 anni fa | 0

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Do you think that MATLAB is expensive?
Yes, I think it is expensive. In New Zealand, it's about \$2000 per toolbox. The compiler is over \$8000. The work I was doin...

quasi 12 anni fa | 0

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Can you use cell or struct as function input？
Yes, and yes. I'm puzzled that you're asking this here when you could quite easily test for yourself... Part of the process ...

quasi 12 anni fa | 3

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Save data from a loop
I think this might be what you want: for f = 1:40 for g = 1:40 i = (f-1) * 40 + g; dpTxcouple1(:,:,i) = ...

quasi 12 anni fa | 0

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If it really is about something cool, then I'm in agreement with the others. Go for it... People could still add their own ans...

quasi 12 anni fa | 0

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can someone explain this code?
|x1_Y| is an array of indices. You're doing a boolean test on |x1(10:300)| to determine if a point is an outlier. That is, it ...

quasi 12 anni fa | 0

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Need some assistance with "if" command
Oh, the better way is to use the proper MATLAB error function: if a < 0 error( 'Not a valid input.' ); end

quasi 12 anni fa | 0

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Need some assistance with "if" command
If you don't have a function or anything to return from, there's a sneaky little trick you can use. This can be useful for othe...

quasi 12 anni fa | 0

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As a Software Engineer, Why should I use MATLAB?
From one developer to another, the answer is: *why not??* What do you have to lose from having another tool (or rather, arsen...

quasi 12 anni fa | 1

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frequency

quasi 12 anni fa | 0

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What do I have to do to sort strings properly in Listbox?
Don't ask the same question just because nobody answered it yesterday. If you are impatient, write a comment on it to bump it b...

quasi 12 anni fa | 0

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how to convert Julian date to Gregorian date ?
Use |datestr|

quasi 12 anni fa | 0

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realtime data streaming between matlab and opencv, visual c++
How "realtime" do you need? If you were polling a file multiple times a second, would that be sufficient? Can you do your anal...

quasi 12 anni fa | 0

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fprint error
Like the error message says, some of your inputs are structs, and that's not allowed. Run the following code to check the types...

quasi 12 anni fa | 0

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What is the purpose of this line in MATLAB's "factorial.m" function?
I would hazard that it is there to handle the special case of computing zero-factorial, which of course is 1.

quasi 12 anni fa | 0

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importing csv array of unknown size, characters
So the general thing is this... Keep track of the current state outside the loop: line_num = 0; % Current CSV line number...

quasi 12 anni fa | 1

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Non-numeric matrix to string
It's not a matrix. It's a cell array. You can try converting the whole thing to strings with something like: [M{:}] ...

quasi 12 anni fa | 0

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Computer Vision - Feature Detection and Tracking - Tracking a RC car in a video
Of course, but you might have to implement a bunch of complex algorithms yourself. If you're not familiar with vision processin...

quasi 12 anni fa | 0

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Find Min& Max Togather
Well, I do it like this: function [Amin, Amax] = minmax( A ) Amin = min(A); Amax = max(A); end Note: Not to...

quasi 12 anni fa | 0

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Slightly off topic: determining at the Windows system level when my process is done
Why don't you invoke the shutdown as the last thing your MatLab script does?

quasi 12 anni fa | 1

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Matrix to Table format
Are you saying you want to generate the SQL: CREATE TABLE my_table blah blah blah Followed by INSERT INTO my_table ...

quasi 12 anni fa | 0

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Combine Two Different Images With Different Gain Values
Here's what I'd do... Convert all your images to 16-bit. Then take the factor-1 image, multiply it by 10. Then take the fac...

quasi 12 anni fa | 1

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Temporal processing of image stack
Well, I'm not known for my solutions that take advantage of inbuilt MatLab functions... Maybe something like |filter| would be ...

quasi 12 anni fa | 0

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Financial contract value
Just a snippet of coding advice from me... If you need to use a number more than once, especially if it relates to how many v...

quasi 12 anni fa | 0

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Entering data into MATLAB from a csv file containing both data and letters
textscan(currentLine, '%s%s%c%d%d%d%d%f%f')

quasi 12 anni fa | 0

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Deleting X-Y points that are not near other points on a field of data points
Naive (brute force) implementation given by per isakson looks sufficient for this problem. O(N^2) is okay for 900 rows. For la...

quasi 12 anni fa | 0