M_pcolor out of memory? (m_map package)

Hello everybody.

I am currently using Matlabs M_maps package to plot some p-values on top of each lon/lat gridpoint. Currently i have a vector of 64800 longitude values (180x360), a vector of 64800 latitude values, and a vector of p-values for each gridpoint (values between 0 and 1). I would like to plot this on a global projection on top of m_maps global coastlines. I'm trying to do this using m_pcolor, but when i call the command m_pcolor(data(:,1),data(:,2),p(:,1)), where data(:,1) is longitude values, data(:,2) is latitude values, and p(:,1) is p-values for each [lon,lat] datapoint, it returns OUT OF MEMORY error. How come this is happening?

Here is my code so far:

    *

% code
m_proj('hammer','clong',0);
figure('name','1','units','normalized','outerposition',[0.5 0 0.5 1])
%p-values
m_pcolor(data(:,1),data(:,2),p(:,1)); %Out of memory???
m_gshhs_l('color','b','linewidth',0.1); 
hold on;
m_grid('xtick',10,'ytick',8,'linewi',1,'tickstyle','dm','tickdir','in','color','r','XAxisLocation','middle','YaxisLocation','left','linewidth',0.2); % Definer gridparametre
hold on;
m_grid('xtick',10,'ytick',8,'linewi',1,'tickstyle','dm','tickdir','in','color','r','XAxisLocation','middle','YaxisLocation','right','linewidth',0.2); % Definer gridparametre
ax=gca;
h = colorbar('location','Eastoutside');
% c.Label.String = 'EWH [cm]';
set(get(h,'ylabel'),'String','p-values', 'FontSize', 10);
colormap gray %Greyscale colormap*

ps: I tried doing this using m_scatter, which worked, but i run into some problems with the scattered bubbles overlapping each other and generally not looking very nice. Especially, when I'm moving more south/north, the bubbles begins overlapping because [lon,lat] points are closer to each other there than at the equator, due to Earths curvature. So I'm looking for a plotting method that is not dependant on the size of the plotting point.