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Always!
29%
It depends
14%
Never!
21%
I didn't know that was possible
36%
1810 Stimmen
goc3
goc3
Last activity am 3 Dez. 2024 um 13:54

I was browsing the MathWorks website and decided to check the Cody leaderboard. To my surprise, William has now solved 5,000 problems. At the moment, there are 5,227 problems on Cody, so William has solved over 95%. The next competitor is over 500 problems behind. His score is also clearly the highest, approaching 60,000.
Please take a moment to congratulate @William.
goc3
goc3
Last activity am 7 Jun. 2024

There are a host of problems on Cody that require manipulation of the digits of a number. Examples include summing the digits of a number, separating the number into its powers, and adding very large numbers together.
If you haven't come across this trick yet, you might want to write it down (or save it electronically):
digits = num2str(4207) - '0'
That code results in the following:
digits =
4 2 0 7
Now, summing the digits of the number is easy:
sum(digits)
ans =
13
quick / easy
21%
themed / in a group
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challenge (e.g., banned functions)
13%
puzzle / game
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educational
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other (comment below)
3%
117 Stimmen
isstring
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ischar
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iscellstr
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isletter
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isspace
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ispunctuation
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2455 Stimmen
Don't use / What are Projects?
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1–10
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11–20
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21–30
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31–50
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51+ (comment below)
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4070 Stimmen
2
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3
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4
59%
6
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8
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Other (comment below)
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6419 Stimmen
numel(v)
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length(v)
13%
width(v)
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nnz(v)
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size(v, 1)
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sum(v > 0)
31%
2537 Stimmen
ismissing( { [ ] } )
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ismissing( NaN )
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ismissing( NaT )
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ismissing( missing )
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ismissing( categorical(missing) )
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ismissing( { '' } ) % 2 apostrophes
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896 Stimmen
isempty( [ ] )
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isempty( { } )
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isempty( '' ) % 2 single quotes
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isempty( "" ) % 2 double quotes
24%
c = categorical( [ ] ); isempty(c)
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s = struct("a", [ ] ); isempty(s.a)
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1324 Stimmen
sort(v)
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unique(v)
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union(v, [ ])
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intersect(v, v)
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setdiff(v, [ ])
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All return sorted output
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1193 Stimmen
s = ['M','A','T','L','A','B']
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char([77,65,84,76,65,66])
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"MAT" + "LAB"
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upper(char('matlab' - '0' + 48))
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fliplr("BALTAM")
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rot90(rot90('BALTAM'))
30%
2929 Stimmen
eye(3) - diag(ones(1,3))
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0 ./ ones(3)
9%
cos(repmat(pi/2, [3,3]))
16%
zeros(3)
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A(3, 3) = 0
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mtimes([1;1;0], [0,0,0])
12%
3009 Stimmen
goc3
goc3
Last activity am 6 Nov. 2023

Have you ever learned that something you were doing manually in MATLAB was already possible using a built-in feature? Have you ever written a function only to later realize (or be told) that a built-in function already did what you needed?
Two such moments come to mind for me.
1. Did you realize that you can set conditional breakpoints? Neither did I, until someone showed me that feature. To do that, open or create a file in the editor, right click on a line number for any line that contains code, and select Set Conditional Breakpoint... This will bring up a dialog wherein you can type any logical condition for which execution should be paused. Before I learned about this, I would manually insert if-statements during debugging. Then, after fixing each bug, I would have to delete those statements. This built-in feature is so much better.
2. Have you ever needed to plot horizontal or vertical lines in a plot? For the longest time, I would manually code such lines. Then, I learned about xline() and yline(). Not only is less code required, these lines automatically span the entire axes while zooming, panning, or adjusting axis limits!
Share your own Aha! moments below. This will help everyone learn about MATLAB functionality that may not be obvious or front and center.
(Note: While File Exchange contains many great contributions, the intent of this thread is to focus on built-in MATLAB functionality.)
1
33%
2
34%
3
18%
4
5%
5
3%
6+
6%
1643 Stimmen
<= 6 GB
10%
7–12 GB
26%
13–22 GB
34%
23–46 GB
19%
47–90 GB
6%
>= 91 GB
6%
15925 Stimmen
Yes, the available tools are great
12%
Yes, the available tools need help
6%
No, but I would like to
14%
No, it is not important to me
7%
What is test-driven development?
61%
1955 Stimmen
Always
12%
Sometimes
11%
In the past, but not now
3%
Never
20%
What is Simulink Project?
53%
2443 Stimmen
Always
8%
Sometimes
9%
In the past, but not now
2%
Never
23%
What is MATLAB Project?
58%
4533 Stimmen
A bunch of quick, simple problems
16%
A structured, educational set
15%
Brain-teasers
16%
Random miscellany
3%
Something else
2%
What are Problem Groups?
49%
1777 Stimmen
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