How to find the value before max value for vector for each 10 rows

i have a vector , A=1:1:100

I want to find the values befor max values , so the result wii be, 9 19 29 39 49 59 69 79 89 99

Answer 1

[Karim]

Hi see below for the stept to obtain such a vector

% set up the 'max row value indicator'
n = 10

n = 10

% create array A
A = 1:100

A = 1×100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

% reshape into a matrix with a given numeber of elements:
B = reshape(A, [], n)

B = 10×10

1 11 21 31 41 51 61 71 81 91 2 12 22 32 42 52 62 72 82 92 3 13 23 33 43 53 63 73 83 93 4 14 24 34 44 54 64 74 84 94 5 15 25 35 45 55 65 75 85 95 6 16 26 36 46 56 66 76 86 96 7 17 27 37 47 57 67 77 87 97 8 18 28 38 48 58 68 78 88 98 9 19 29 39 49 59 69 79 89 99 10 20 30 40 50 60 70 80 90 100

% find the max element for each group (which in this case has 10 elements),
% but we exclude the last (i.e. 10th) elements
maxval = max(B(1:end-1,:),[],1)

maxval = 1×10

9 19 29 39 49 59 69 79 89 99

[abdullah al-dulaimi]

maxval =

0×100 empty double matrix? i gent this comment

[abdullah al-dulaimi]

solved, thank you