Error:Index exceeds matrix dimensions.

I have two arrays;

 onpointX1 =

   NaN   NaN   NaN   NaN   NaN   NaN   NaN   

 onpointX2 =

       NaN       NaN       NaN       NaN       NaN    0.5830    0.5161

Note that the elements which are not NaN always equal to crossX(k,1) or crossX(k,2).

I run a for loop,

 for k=1:length(onpointX1) 
  onpointX1(8)=onpointX1(1);
  onpointX2(8)=onpointX2(1);

I get an error when the for loop is at k=7

Index exceeds matrix dimensions.

at;

    else if isnan(onpointX1(k)) && onpointX2(k)==crossX(k,2)&& onpointX1(k+1)==crossX(k+1,1) && isnan(onpointX2(k+1))

I can not understand why this happens because I have defined onpointX1(8) and onpointX2(8) right after initiationg the for loop.

Can anybody help me with this? Thanks.

[Alexandra Harkai]

What is the actual code you're running?

What is crossX?

Answer 1

[Jan]

Use the debugger for further investigations:

dbstop if error

Run the code again until it stops at the error and check the dimensions of the used variables:

size(onpointX1)
size(onpointX2)
size(crossX)

Then you will find out, which variable causes the error.

Debugging locally is more efficient than asking the forum, which cannot guess the details.