changing ticks position on the graph

Hi,

I have a problem that seems to be easy. I have created a heat map in form of matrix but the scale I want to set from -400 to 400. I was able to change the axes numbers but the ticks are at the centre of each square instead to be in between them. How to do it?

Thank you,

Regards,

Matti

[Dyuman Joshi]

"... but the ticks are at the centre of each square instead to be in between them."

Ticks are where they are supposed to be.

If you move ticks to the edges of squares, they will be skewered and won't be symmetrical.

[DGM]

If the SW element of the heatmap represents data at (-400, -400), then that's where they're supposed to be in order to communicate that relationship.

If that element represents data at (-440, -440), then you might want to fix your x,y data so that it actually corresponds.

[Wade]

thank you for your advice!

BW,

Matti

Answer 1

[Bjorn Gustavsson]

If you have coordinates for the edges of the cdata-elements then you can either adjust things manually to get what you want:

dx = 80;
dy = 80;
heatmap(x+dx/2,y+dy/2,cdata)
set(gca,'xtick',x,'ytick',y)

Or perhaps use pcolor instead of heatmap:

dx = 80;
dy = 80;
pcolor([x(:)',x(end)+dx],[y(:),y(end)+dy],cdata([1:end,end],[1:end,end])),shading flat

That should be rather close, I hope. This centre-of-pixel vs edge-of-pixel is a problem that will always persist and never have a solution that satisfies every user in all cases - we just have to learn to work around the given behaviours to get the output that corresponds to our use-cases.

HTH

[Wade]

I will try these codes,

thanks a lot,

BW,

Matti