Daniel Ennis

Apparently, when consecutive x,y points are the same dl will be [0,0,1] and so you end up with alpha and cross(Nz,dl) being 0 yielding a rotation matrix R that is just NaNs and nothing will be plotted for that segment.

There may be more elegant fixes but checking for that and using R=eye(3) if it is nan seems to solve this.

if(isnan(R(1)))
R=eye(3);
end

This works great! Is there any way to change the color mapping in terms of intensity and/or using other colormaps?

I have a 119*255 cell array that contains land and sea area, I set the earth values to NaN and try to use quiver for plot velocity arrow but the result does not look good, because there is a dot on every land point and the arrows are not detectable.
I tried to prepare a matrix of x y u and v and then use quiver the result comes better but not good yet, because sometimes there are 2 arrow from 1 point.
look at this: https://sites.google.com/site/physic4ocean/Home/om2.png?attredirects=0&d=1

would someone help me to prepare a good look of current in this large area?

is it possible to send me a file please?

I am using R2010a and my original file is a nc file.

thank you
Dandelion
apt.man@gmail.com