Getting an error for setting gca tick marks

In my code, I have:

set(gca,'YTick',energy_pixel);

I'm getting an error message, saying: 'Value must be a vector of type single or double whose values increase'. However, the vector for 'energy_pixel' is:

[0, 0, 0, 0, 71, 188, 352, 595, 996]

Can someone tell me whats wrong? I can't change the values, so how can I work around this problem?

[Adam]

[0, 0, 0, 0,...]

clearly do not increase.

[Brianna Florio]

@Adam, I can see it doesn't increase, but I was hoping there was still a way to do this without manipulating the data. Do you know what I can do to work around this problem?

[Adam]

I don't know what you are trying to do. Why do you want 4 ticks at 0?

set( gca, 'YTick', unique( energy_pixel ) )

may give what you want, but it's hard to say. If you really want 4 0's equally spaced at some interval along the x axis then you'll have to do something more involved because you are basically redefining the mapping of the x-axis to be non-linear.