creating a repeated matrix 2

Hi all,

I have

k1x=repmat(h(19,1), [3,1])   ;

k2x=repmat(h(37,1), [3,1])   ;

 k3x=repmat(h(55,1), [3,1])   ;

 k4x=repmat(h(73,1), [3,1])   ;

k5x=repmat(h(91,1), [3,1])   ;

kxtotal= [k1x; k2x;k3x;k4x;k5x];

h is a column of numnbers As you can see

               37=19+18

               55=37+18

               73=55+18.

So I add the number 18 to obtain the sequence 19, 37, 55, 73 ...

Is there a better or clever way to construct kxtotal.

To be honest Isakson, I would prefer (as you did in my previous question) something like

   ixs    = repmat( [1:6], [3,1] );
   ktotal = arrayfun( @(ii) sprintf('S%u',ii), ixs(:), 'uni', false );

that is, the approach without the loop.

thanks

[Sabbas]

I think that the solution is

ktotal = repmat( [h(19:18:19+4*18,1)], [3,1] );

Am i right?

thanks

[per isakson]

In my checklist for good code "Easy to read and understand" is one of the top items. I find the for-loop variant of my previous answer easier to understand.

If the performance of the for-loop is not good enough I search for another solution.

[Sabbas]

thanks Isakson!

[per isakson]

"h(19,1)" that is not the 19:th value of a column vector?

[Sabbas]

yes h(19,1)" is the 19:th value of a column vector.

I just realized that what I proposed is wrong

that is

ktotal = repmat( [h(19:18:19+4*18,1)], [3,1] );

is wrong

[per isakson]

How do I get the vector, h?

[Sabbas]

Sorry h=rand(100,1)

Answer 1

[per isakson]

Try this

    ktotal = repmat( transpose( h([19:18:19+4*18]) ), [3,1] );
    ktotal = ktotal(:);

I use "transpose" instead of the blip, "'", because the latter is too easy to miss.

[Sabbas]

Many thanks! it is ok!