converting a vector to matrix

I'm doing practice questions, and I am stuck. If the vector is x=[9,4,0,7] and i want to create a Matrix with 4 rows (the original vector, the recipricol, the factorial of the originals using my own code i already wrote, and the factorial using matlab's factorial function) while also putting ruler lines above and below the outputs. How the heck does one do this?

Answer 1

[David Hill]

Not sure if this is what you are after, but it could be a starting point. Not sure what you mean by ruler lines above and below.

y=[x;1./x;factorial(x)];

[Charlotte Reed]

This is the actual question for more reference:

A vector is given by x = [9, 4, 0 ,7]. Create a program that creates the vector x, then creates a matrix M from this vector. The matrix M has four rows, as follows:

• The original vector, x

• The reciprocal of x

• The factorial of the elements in x computed using the myFactorial function from the last question

• The factorial of the elements in x computed using MATLAB's factorial function.

Output the matrix M, with a ruler line above and below. For the numeric output, use MATLAB's fprintf function, creating the four lines of output in a single statement that executes once. For each value, use a field width of 15 characters, including 4 decimal places.

[David Hill]

x=[9 4 0 7];
M=[x;1./x;myFactorial(x);factorial(x)];

I will leave the printing to you using fprintf() function.

[Charlotte Reed]

Still wasn't able to code it

[David Hill]

show me the code for your myFactorial() function

[Charlotte Reed]

[David Hill]

There are lots of good examples in the fprintf() function. You just need to experiment with the syntac until you get the format you want.

[Charlotte Reed]

im not able to get the answer whatsoever, let alone fprint tit

[David Hill]

myFactorial needs to be a function!

function y=myFactorial(x)%input x can be an array
x(x==0)=1;%takes care of 0!
for k=1:length(x)
    y(k)=prod(1:x(k));
end
end

Then this should work for you.

x=[9 4 0 7];
M=[x;1./x;myFactorial(x);factorial(x)];

I get:

M =

   1.0e+05 *

   0.000090000000000   0.000040000000000                   0   0.000070000000000
   0.000001111111111   0.000002500000000                 Inf   0.000001428571429
   3.628800000000000   0.000240000000000   0.000010000000000   0.050400000000000
   3.628800000000000   0.000240000000000   0.000010000000000   0.050400000000000

[Charlotte Reed]

thanks so much!! and for the

fprintf('------------- ------------- ----------- ------------\n')
fprintf('M\n')
fprintf('------------- ------------- ----------- ------------\n')

?

Thanks so much for the help, pretty new to it and having trouble.

[Walter Roberson]

fprintf('------------- ------------- ----------- ------------\n')
fprintf('%13.5f %13.5f %13.5f %13.5f\n', M');
fprintf('------------- ------------- ----------- ------------\n')

The choice of 13.5f is speculation on my part: you will want to play around with the .5 part.