How can I change the Nan values in a matrix by the values in cells array?

f=[1 nan 3 4 5 6;nan 3 nan 5 6 7;3 nan 5 6 nan 8; 4 5 6 7 8 nan;5 6 nan 8 9 0;6 7 8 nan 0 2]

% I want to replace each nan values by one of the following data

data=[8 0 5 9 7 3 6 4]

Input_variables = num2cell(data)

Input_variables{:}

% it works till here. Then, when I want to have the replacment:

f(Input_variables{:})

% I got this error:

Index in position 1 exceeds array bounds. Index must not exceed 6.

Answer 1

[VBBV]

f(pt) = cell2mat(data)

Use cell2mat

[Hajar Alshaikh]

I got the same error when I used :

f(pt) = cell2mat(data)

Error using indexing

Invalid indexing or function definition. Indexing must follow MATLAB indexing. Function arguments must be symbolic variables, and function body must be sym expression.

[VBBV]

f=[1 nan 3 4 5 6;nan 3 nan 5 6 7;3 nan 5 6 nan 8; 4 5 6 7 8 nan;5 6 nan 8 9 0;6 7 8 nan 0 2];
numnan=8;% number of nan in a matrix
for s =1:numnan 
    var(s) =min(min(f,[],'omitnan'))+(max(max(f,[],'omitnan'))-min(min(f,[],'omitnan')))*rand();
  end
double(var)

ans = 1×8

8.5542 7.7788 0.9557 4.5658 3.8924 5.0489 1.3913 3.0045

data= num2cell(double(var)) % why this ?

data = 1×8 cell array
    {[8.5542]}    {[7.7788]}    {[0.9557]}    {[4.5658]}    {[3.8924]}    {[5.0489]}    {[1.3913]}    {[3.0045]}

pt = find(isnan(f));
% Replace NaN by data value
f(pt) = double(var)

f = 6×6

1.0000 7.7788 3.0000 4.0000 5.0000 6.0000 8.5542 3.0000 4.5658 5.0000 6.0000 7.0000 3.0000 0.9557 5.0000 6.0000 1.3913 8.0000 4.0000 5.0000 6.0000 7.0000 8.0000 3.0045 5.0000 6.0000 3.8924 8.0000 9.0000 0 6.0000 7.0000 8.0000 5.0489 0 2.0000

f(pt) = cell2mat(data) 

f = 6×6

1.0000 7.7788 3.0000 4.0000 5.0000 6.0000 8.5542 3.0000 4.5658 5.0000 6.0000 7.0000 3.0000 0.9557 5.0000 6.0000 1.3913 8.0000 4.0000 5.0000 6.0000 7.0000 8.0000 3.0045 5.0000 6.0000 3.8924 8.0000 9.0000 0 6.0000 7.0000 8.0000 5.0489 0 2.0000

[VBBV]

why you would like to convert to cell in this line ?

data= num2cell(double(var))

[Hajar Alshaikh]

because when I tried to use the double (var) direct without convert them to the cell, I got this error

Brace indexing is not supported for variables of this type.

Error in cell2mat (line 42)

cellclass = class(c{1});

Error in PSDHNKL (line 27)

f(pt) = cell2mat(double(var))

[VBBV]

f(pt) = cell2mat(double(var))

Ok. That's because the above input is incorrect since the cell2mat takes cell arrays as input and converts to numeric array . But double(var) is not a cell array data type. It's already numeric,hence it's shows error when it encounters incorrect brace such as ( or [ Cell arrays begin with '{'. e.g. in this line

f={1 nan 3 4 5 6;nan 3 nan 5 6 7;3 nan 5 6 nan 8; 4 5 6 7 8 nan;5 6 nan 8 9 0;6 7 8 nan 0 2};

Hope this clears your doubt

[Hajar Alshaikh]

Thank you so much for your help

Answer 2

[Akira Agata]

If you want to replace NaN by the given value in linear index order, the following will be one possible solution:

% Given matrix
f = [...
  1 nan 3 4 5 6;...
  nan 3 nan 5 6 7;...
  3 nan 5 6 nan 8;...
  4 5 6 7 8 nan;...
  5 6 nan 8 9 0;...
  6 7 8 nan 0 2];

% Given data value
data = [8 0 5 9 7 3 6 4];

% Linear index of NaNs in the matrix f
pt = find(isnan(f));

% Replace NaN by data value
f(pt) = data;

% Show the result
disp(f)

     1     0     3     4     5     6
     8     3     9     5     6     7
     3     5     5     6     6     8
     4     5     6     7     8     4
     5     6     7     8     9     0
     6     7     8     3     0     2

[Hajar Alshaikh]

I got this error:

Error using indexing

Invalid indexing or function definition. Indexing must follow MATLAB indexing. Function arguments must be symbolic variables, and function body must be sym expression.

I will copy the code from the begining:

f=[1 nan 3 4 5 6;nan 3 nan 5 6 7;3 nan 5 6 nan 8; 4 5 6 7 8 nan;5 6 nan 8 9 0;6 7 8 nan 0 2]

numnan=8 % number of nan in a matrix

for s =1:numnan

var(s) =min(min(f,[],'omitnan'))+(max(max(f,[],'omitnan'))-min(min(f,[],'omitnan')))*rand();

end

double(var)

data= num2cell(double(var))

pt = find(isnan(f))

% Replace NaN by data value

f(pt) = data

[Hajar Alshaikh]

Also, this error :

Conversion to double from cell is not possible.