How to write function for above combine matrix?

A = [2,4]

A = [1 1 1 1 ; 1 1 1 1; 2 2 2 2; 2 2 2 2; 3 3 3 3; 3 3 3 3]

what will be the funtion for A= [7,4]

or using any random variable?

A should give (3n by m) matrix

[Walter Roberson]

See repelem() and repmat()

[dpb]

And possibly kron()

[Adam Danz]

What would A[7,3] look like?

[Walter Roberson]

I do not understand why 7 3 would result in single rows of 1 and 11, and not two rows of 1 with no 11.

[Walter Roberson]

RAHUL ANTIL comments to Adam Danz

A[7,3] A = [ 1     1     1
    2     2     2 
    2     2     2
    3     3     3 
    3     3     3
    4     4     4 
    4     4     4
    5     5     5
    5     5     5
    6     6     6 
    6     6     6
    7     7     7
    7     7     7
    8     8     8
    8     8     8
    9     9     9
    9     9     9
    10    10    10
    10    10    10
    11     11    11 ]

[Walter Roberson]

RAHUL ANTIL comments to me:

sorry its 2 rows of 1 and single row of 11

[Walter Roberson]

RAHUL, please do not use "flag" unless you need to alter [sic. "alert" is what was intended I think (dpb] the moderators about something.

To respond to us, click on the "Comment on this Question" link just below this box.

[RAHUL ANTIL]

A(n,m) gives (3n,m) matix

A[7,3] A = [ 1     1     1
    1     1     1
    2     2     2 
    2     2     2
    3     3     3 
    3     3     3
    4     4     4 
    4     4     4
    5     5     5
    5     5     5
    6     6     6 
    6     6     6
    7     7     7
    7     7     7
    8     8     8
    8     8     8
    9     9     9
    9     9     9
    10    10    10
    10    10    10
    11     11    11 ]

[Adam Danz]

Sorry, my pattern recognition skills require more time than I'd like to spend trying to figure out the relationship between the input and output. Can you explain the pattern in words?

[RAHUL ANTIL]

Write a function called trio that takes two positive integer inputs n and m. The function returns a 3n-by-m matrix called T. The top third of T (an n by m submatrix) is all 1s, the middle third is all 2-s while the bottom third is all 3-s. For an example,see the code below:

M = trio(2,4)
M =
     1     1     1     1
     1     1     1     1
     2     2     2     2
     2     2     2     2
     3     3     3     3
     3     3     3     3

[My function generate correct pattern when (n) is even.]

[Stephen23]

@RAHUL ANTIL: please show us the function you wrote.

[RAHUL ANTIL]

function T = trio(n,m)
n = 3*n;
w = (n)/2;
y = ceil(w);
A = [1:y]';
B = ones(2,m);
T = kron(A,B);

[Adam Danz]

ahhhh... there we go. That's more valuable than any example or description.

[Adam Danz]

NOTE: The code provided above by OP is apparently incorrect and the pattern is still unexplained.

[vivek jason]

This is what I came up with ...Hope this helps!!!

function T= trio(n,m);
n=3*n;
T1= ones(n/3,m);
T2= 2*ones(n/3,m);
T3= 3*ones(n/3,m);
T= [T1;T2;T3];

Answer 1

[saurav Tiwari]

function T=trio(n,m)
a=ones(n,m);b=2*a;c=3*a;
T=[a;b;c];
end

[saurav Tiwari]

most easiest coding of the world

[Adam Danz]

This does not produced the expected pattern described by OP.

[Chandan Kumar]

function T=trio(n,m)

a=ones(n,m);b=2.*a;c=3.*a;

T=[a;b;c];

he should have added dot to perform array multiplication.

[Walter Roberson]

When at least one of the operands is a scalar then the * operator does element by element multiplication and acts like .*

Answer 2

[Adam Danz]

n = 7;
m = 3;
A = repelem((1:ceil((3*n)/2))',2,m);

[RAHUL ANTIL]

@Adam Danz

Variable A should be size of [21,3] but the output is [22,3].

[Adam Danz]

It's producing the exact same output as your function which, given those inputs, produces a 22x3 matrix.

T = trio(7,3); 

>> size(T)
ans =
    22     3

[RAHUL ANTIL]

The function returns a 3n-by-m matrix called T.

I was getting the same result before.

[Adam Danz]

Your function and the code in my answer produce the exact same results

% YOUR CODE
n = 7;
m = 3;
% T = trio(n,m)
n = 3*n;
w = (n)/2;
y = ceil(w);
A = [1:y]';
B = ones(2,m);
T = kron(A,B);

% MY CODE
n = 7;
m = 3;
A = repelem((1:ceil((3*n)/2))',2,m);

% COMPARE THE RESULTS
isequal(A,T)

ans =
  logical
   1      % <---- exactly the same results

Run that code and look at your T and my A. They are exactly the same.

[RAHUL ANTIL]

Our code print the same result. But my point is that when n=7;m=3, than output matrix size should be [21,3].

our code print the matrix size of [22,3]. That's wrong

[Adam Danz]

How can anyone here know what your code is supposed to do?

[RAHUL ANTIL]

My code is wrong I know that and that's why I'm here seeking for help.

[Adam Danz]

Ok. What patterns are you looking for? Can you explain it in words?

[Walter Roberson]

Change Adam's ceil() to floor(). Then at the end if size(A,1) is not a multiple of 3, append 3-mod(number_of_rows,3) copies of a row with the next integer.

Answer 3

[RAHUL ANTIL]

T = [7,3]
T  =
   [ 1     1     1
     1     1     1
     2     2     2
     2     2     2
     3     3     3
     3     3     3
     4     4     4
     4     4     4
     5     5     5
     5     5     5
     6     6     6
     6     6     6
     7     7     7
     7     7     7
     8     8     8
     8     8     8
     9     9     9
     9     9     9
    10    10    10
    10    10    10
    11    11     11]

I want above pattern, matrix size is [21,3].

[Adam Danz]

What rules did you follow to build this matrix?

[saurav Tiwari]

uhhh combination rule of matrix

[dpb]

Uhhhh...which combinaton "rule" is that?

You have N copies of two but only one for the last...whassup w/ that?

Answer 4

[AN Roza]

V. Given

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5502222
221810.58
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5511591
1172396
00.50.370.20.10.9
x
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Write the answer of the following comment:

a. x(3,5)

b. x(7,7)

c. x(1:5, :)

d. x(1:end, :)

[Walter Roberson]

no, this is a completely incorrect answer to the question asked by RAHUL.

Answer 5

[dpb]

" want above pattern, matrix size is [21,3]."

ADDENDUM/ERRATUM:

[But we have now learned that that is NOT even the correct description of the assignment -- there is no "odd man out" in the desired result, the output is always a multiple of 3x the requested N so there is never an odd set.]

Original solution moved to end solves the problem as first described simply to reproduce a given stated output; will leave but the problem described is solved as

function T=trio(n,m)
% build 3*n x m output matrix with thirds of vectors of 1, 2, 3, respectively.

  T=kron([1:3].',ones(n,m));
end

I would suggest NOT turning in the above Answer to a homework assignment, however -- is NOT going to pass the smell test of something most beginning students will have come up with on own.

"Just sayin'..." :)

END ADDENDUM/ERRATUM --

ORIGINAL ANSWER FOLLOWS...BUT ANSWERS DIFFERENT QUESTION/PATTERN

R=21;C=3;N=2;                       % define parameters, R, C, repeat count
P=kron([1:ceil(R/N)].',ones(N,C));  % pattern complete N*ceil(R/N) rows
P=P(1:R,:);                         % fixup for odd man out if mod(R,N)~-0

results in

>> P=kron([1:ceil(R/N)].',ones(N,C)); P=P(1:R,:)
P =
     1     1     1
     1     1     1
     2     2     2
     2     2     2
     3     3     3
     3     3     3
     4     4     4
     4     4     4
     5     5     5
     5     5     5
     6     6     6
     6     6     6
     7     7     7
     7     7     7
     8     8     8
     8     8     8
     9     9     9
     9     9     9
    10    10    10
    10    10    10
    11    11    11
K>> 

Answer 6

[Cyrus David Pastelero]

function T = trio(n,m)

T1 = ones(n,m); //this just creates the body for us to use, you can also use zeros

T = [T1;T1+1;T1+2]; //adding them base on the required output

end

[Adam Danz]

This doesn't even come close to producing the desired outputs.

To come closer, you would need a 3rd input to indicate the number of replications and then you could use that 3rd input to produce T instead of manually concatenating replications of T1.

But even then the function wouldn't be doing what the OP is asking for.

Answer 7

[Ibad Ur Rahman]

I got the following answer to this question.....

function T=trio(n,m)
a=ones(n,m);
b=2*ones(n,m);
c=3*ones(n,m);
T=cat(1,a,b,c);
end