problem with gradient- index exceeds matrix dimensions.

Does anyone know what is the problem with the following code? Many thanks.

>> ss=[ 1 9 19 31 45 61 79 99 121 145]; >> t2 = gradient(ss)

and I received error message below: "Index exceeds matrix dimensions."

I checked matlab help file, it says: FX = gradient(F), where F is a vector, returns the one-dimensional numerical gradient of F. Here FX corresponds to ∂F/∂x, the differences in x (horizontal) direction.

So I don't understand why it is not working now.

Answer 1

[Guillaume]

Most likely you have a variable called gradient, so instead of calling the function gradient you're indexing into the variable. Since the variable has less than 145 elements, you get 'index exceeds matrix dimension'

Don't use matlab function names as variable names.

[Thorsten]

Use

which gradient

just before gradient(ss) to see what gradient actually is.

Answer 2

[June]

Thanks for reminding me. Yes, I am testing someone else's code.