What's the problem about this loop?

Hello everyone,

I created graph G It has 4 nodes (1,2,3,4), and 3 edges.

I created values G.Nodes.Zp, and I have created values G.Nodes.Z

G.Nodes.Zp values are [0,0,1,1]

I have control array which is

kontrola=[1;2;NaN;NaN]

I created a loop as follows

for i=1:1:length(kontrola)
if kontrola(i)==NaN
G.Nodes.Z(i)=G.Nodes.Zp(i);
end
end

But it doesn't work, no error, no anything.

By my logic G.Nodes.Z(3)&G.Nodes.Z(4) should get values from G.Nodes.Zp(3)&G.Nodes.Zp(4).

Thank you for your time,

Denis

Answer 1

[per isakson]

Test

>> nan==nan
ans =
     0

Replace

kontrola(i)==NaN

by

isnan(kontrola(i))

and run your code.

See Nan, Not-a-Number

...
Because two NaNs are not equal to each other, logical operations involving 
NaNs always return false, except ~= (not equal). Consequently,

NaN ~= NaN 
ans =
     1
NaN == NaN
ans =
     0

and see Debug a MATLAB Program