How can I get slope from DEM data?

Hi, I'm undergraduate student from Yonsei University, Seoul. I have a question about MATLAB.

I have a DEM data like this picture.

Each row and column indicates the length of data set(1952X2101), and each value means elevation.

I want to calculate the slope of radom radial degree.

If I put random radial degree like 45 degree(0-90 degree), MATLAB shows slope like 0.08 (in ratio)

How can I make this one?

Thanks for reading.

[darova]

I don't understand the question. Can you please explain more?

[HyoJae Lee]

Sorry that I'm not good at English.

For example, there is a matrix 5X5 like

1 2 4 8 10

1 2 4 8 10

1 2 4 8 10

1 2 4 8 10

1 2 4 8 10

this value means elevation of each point.

I choose starting point (1,1) --> 1. then, I put radial degree like 45. In this case, slope will be 1.697.

If I put radom radial degree like 60, how can I get radial slope from this data?

[KSSV]

(1,1) --> 1. then, I put radial degree like 45. In this case, slope will be 0.4.

How slop is 0.4? To get slope you need two points right? What is other point?

[HyoJae Lee]

Oh, I was totally wrong. Sorry, It is 1.697056...

I calculated slope by y's rate of change / x's rate of change.

y can be 1 2 4 8 10.

and x is row(or column) number 1 2 3 4 5 * square root 2. (In 45 degree, data length of each point will be increased by square root 2)

I want to get the entire radial slope, not just two points, which has starting point of (1,1).

This picture might help. (This picture is visualization of the matrix.)

Thanks for helping me.