How to compare each element of a matrix with a number? And then star it out

I have a 23x1 matrix of numbers, and i want to compare with a single number to see if any of the numbers in the matrix are greater or equal than it. And if that is the case, then I want there to be a star (or something of that kinda) that is added beside that number so that i can easily recognize it when i print it to the command window.

For instance I have the matrix, [1 2 3 4 5 6 7]' and for instance, i want o campare it with 6, then i would like it to output [1 2 3 4 5 6* 7*]'

[Walter Roberson]

You would need to construct character array, not numeric, if you wanted to be able to just output the value without using special code.

If you were willing to write a small function that did the output for you, then you could hold the original data and you could have a second variable indicating which one had been seen, and you could have your function do the appropriate output.

[Nick Bos]

Could you do an example?

[Bob Thompson]

Identifying the numbers numerically is rather easy.

A = rand(23,1);
check = 6;
B = A(A >= 6);  

This returns an array, B, of the numbers greater than your check number. If you want to know where those numbers are then you can just use B = A>= 6; which generates a matrix of 1s and 0s where 1s indicate numbers that meet the condition.

Writing the output with stars would generally be an expansion of this type of check. Since all you want to do is print it to the command window I don't know that Walter's suggestion of a separate function is necessary, but I also don't use fuctions as often as I probably should.

str = '';
for i = 1:length(A);
    if A(i) >= check
        tmp = [num2str(A(i)),'* '];
    else
        tmp = [num2str(A(i)),' '];
    end
    str = [str tmp];
end
str

[Walter Roberson]

This is the kind of operation one does during debugging, so one would probably want to do this upon demand. It is easier to put it into aa function than to copy and paste the code every time one wants to execute it interactively .

Answer 1

[Andrei Bobrov]

a = [1 2 3 4 5 6 7]';
c = 6;

lo = a >= c;
z = ["","*"]';
out = a + z(lo+1);

[Walter Roberson]

Note this requires R2017a or later; with a small modification it could be used with R2016b, but no earlier.

Answer 2

[Stephen23]

>> V = 1:7;
>> N = 6;
>> C = cellstr(num2str(V(:)))
>> X = V>=N;
>> C(X) = strcat(C(X),'*')
C = 
    '1'
    '2'
    '3'
    '4'
    '5'
    '6*'
    '7*'

Reshape and display as required.