How can I create a new matrix by using existing values in a column?

I've a column inluding the values of

>> B=[0.100;0.250;0.200;0.120;0.080;0.060;0.055;0.040;0.020]

B =

0.1000

0.2500

0.2000

0.1200

0.0800

0.0600

0.0550

0.0400

0.0200

But I want to make it as

0.100 0 0 0 0 0 0 0 0

0.250 0.100 0 0 0 0 0 0 0

0.200 0.250 0.100 0 0 0 0 0 0

0.120 0.200 0.250 0.1 0 0 0 0 0

0.080 0.120 0.200 0.250 0.1 0 0 0 0

0.060 0.080 0.120 0.200 0.25 0.1 0 0 0

0.055 0.060 0.080 0.120 0.2 0.25 0.1 0 0

0.040 0.055 0.060 0.080 0.12 0.2 0.25 0.1 0

0.020 0.040 0.055 0.060 0.08 0.12 0.2 0.25 0.1

How can I do it?

Answer 1

[Stephen23]

Simpler and much more efficient to use toeplitz:

>> B = [0.100;0.250;0.200;0.120;0.080;0.060;0.055;0.040;0.020];
>> C = zeros(size(B));
>> C(1) = B(1);
>> M = toeplitz(B,C)
M = 
   0.100   0       0       0       0       0       0       0       0      
   0.250   0.100   0       0       0       0       0       0       0      
   0.200   0.250   0.100   0       0       0       0       0       0      
   0.120   0.200   0.250   0.100   0       0       0       0       0      
   0.080   0.120   0.200   0.250   0.100   0       0       0       0      
   0.060   0.080   0.120   0.200   0.250   0.100   0       0       0      
   0.055   0.060   0.080   0.120   0.200   0.250   0.100   0       0      
   0.040   0.055   0.060   0.080   0.120   0.200   0.250   0.100   0      
   0.020   0.040   0.055   0.060   0.080   0.120   0.200   0.250   0.100

Answer 2

[TADA]

B=[0.100;0.250;0.200;0.120;0.080;0.060;0.055;0.040;0.020];
n = length(B);

% prepare indices
idx = 0:(length(B)-1);

% splicing and padding
func = @(i) padarray(B(1:n-i), i, 'pre');

% execute padding and splicing element-wise
c = arrayfun(func, idx, 'UniformOutput', false);

result = cell2mat(c)

result =

    0.1000         0         0         0         0         0         0         0         0
    0.2500    0.1000         0         0         0         0         0         0         0
    0.2000    0.2500    0.1000         0         0         0         0         0         0
    0.1200    0.2000    0.2500    0.1000         0         0         0         0         0
    0.0800    0.1200    0.2000    0.2500    0.1000         0         0         0         0
    0.0600    0.0800    0.1200    0.2000    0.2500    0.1000         0         0         0
    0.0550    0.0600    0.0800    0.1200    0.2000    0.2500    0.1000         0         0
    0.0400    0.0550    0.0600    0.0800    0.1200    0.2000    0.2500    0.1000         0
    0.0200    0.0400    0.0550    0.0600    0.0800    0.1200    0.2000    0.2500    0.1000

[Onur Güven]

@TADA thanks for your answer. That's exactly what I 'm looking for.

@Mark Sherstan, thanks for your answer. It worked but TADA's answer is more suitable for me.

Answer 3

[Mark Sherstan]

Try this:

B = [0.100;0.250;0.200;0.120;0.080;0.060;0.055;0.040;0.020]
A = zeros(1,length(B));

for ii = 1:length(B)
    A = circshift(A,1);
    A(1) = B(ii)
end