Zero Matrix Values using Indices

Hi All,

I have two matrices. The first is an 8x6 matrix (Speed_ENU) that contains some measured data. The second matrix (HubHeight) contains integers corresponding to particular rows in the first matrix. I want to set the values corresponding the indices in ind to zero. I have the follwing code so far. The comments in the code explain what I am trying to do.

This is as far as I get. How can I set the values in Speed_ENU corresponding to the Indexes in ind to zero???????

clc
clear all

Speed_ENU = [1,3,6,14,25,33; 11,12,15,45,15,67;1,32,16,4,25,3; 11,12,5,45,15,7;11,32,6,4,25,33; 1,12,5,44,15,67;11,31,6,4,25,3; 1,22,5,5,9,7 ]

Speed_ENU = 8×6

1 3 6 14 25 33 11 12 15 45 15 67 1 32 16 4 25 3 11 12 5 45 15 7 11 32 6 4 25 33 1 12 5 44 15 67 11 31 6 4 25 3 1 22 5 5 9 7

HubHeight = [6,6,6,4,5,5]

HubHeight = 1×6

6 6 6 4 5 5

[sz1,sz2]=size(Speed_ENU);

row = HubHeight;  %We want to set all the values at Hub Height to zero  
col = [1:sz2];
sz = size(Speed_ENU)

sz = 1×2

8 6

ind = sub2ind(sz,row,col) %Returns the linear Indices corresponding to the row and column subscripts in Speed_ENU 

ind = 1×6

6 14 22 28 37 45

 Speed = (Speed_ENU(ind)); %This is as far as I get. How can I set the values in Speed_ENU corresponding to 
                           % the Indexes in ind to zero??????? 
 
 

Answer 1

[Voss]

Speed_ENU = [1,3,6,14,25,33; 11,12,15,45,15,67;1,32,16,4,25,3; 11,12,5,45,15,7;11,32,6,4,25,33; 1,12,5,44,15,67;11,31,6,4,25,3; 1,22,5,5,9,7]

Speed_ENU = 8×6

1 3 6 14 25 33 11 12 15 45 15 67 1 32 16 4 25 3 11 12 5 45 15 7 11 32 6 4 25 33 1 12 5 44 15 67 11 31 6 4 25 3 1 22 5 5 9 7

HubHeight = [6,6,6,4,5,5];

[sz1,sz2] = size(Speed_ENU);

% row = HubHeight;
% col = 1:sz2;
% sz = size(Speed_ENU);
% ind = sub2ind(sz,row,col);

% no need for the variables row, col, sz:
% (no need for ind either, really)
ind = sub2ind([sz1 sz2],HubHeight,1:sz2)

ind = 1×6

6 14 22 28 37 45

Speed_ENU(ind) = 0

Speed_ENU = 8×6

1 3 6 14 25 33 11 12 15 45 15 67 1 32 16 4 25 3 11 12 5 0 15 7 11 32 6 4 0 0 0 0 0 44 15 67 11 31 6 4 25 3 1 22 5 5 9 7

[Ben Whitby]

No. I need to set the indidual cells corresponding to the indices in ind ( 6 14 22 28 37 45) to zero. Not the entire row. The final matrix should look like this:

1 3 6 14 25 33

11 12 15 45 15 67

1 32 16 4 25 3

11 12 5 0 15 7

1 32 6 4 0 0

0 0 0 44 15 67

11 31 6 4 25 3

1 22 5 5 9 7

[Voss]

OK. I've updated my answer based on your updated question.