Using map2mat for eof analysis!

I have a matrix mm_r of the size 361*361*36; where 36 represent the number of years

i need to make it of size 36*130321

    % Get EOFs:
    G = map2mat(ones(size(mm_r,3),size(mm_r,2)),mm_r);

• *the error message is Attempted to access F(37,1); index out of bounds because size(F)=[36,361].

Error in map2mat (line 30) if F(ix,iy)>0**

[Walter Roberson]

Is mat2map from the pcatool File Exchange contribution?

[Sophia]

Yes, it is from pcatool file excahnge.

Answer 1

[Chad Greene]

Hi Sophia,

Be careful, because map2mat assumes the first dimension is time. For normal climate data (lon*lat*time or lat*lon*time) it's probably easier to use eof, which does all the reshaping for you.

[Sophia]

I did saw the eof before, but i also saw you mentioned there about pcatool so i moved back to pcatool

[Chad Greene]

My eof function is little more than a wrapper for PCATool's caleof function to make it more user friendly.

[Sophia]

So i used this instead

[eofmap,pc] = eof(mm_r,1);

I cannot understand the result, honestly i am not even sure what to expect as a result.

[Chad Greene]

Hi Sophia,

I cannot understand your result either given the information you have provided.

[Sophia]

Hi

I used your eof technique as well..Somehow, does not matter what i choose as N, I mean 2 or 3 the total of all the eof is 99.9%, is there a reason for that or i am missing something..take a look at the codes below

[Sophia]

I changed it to 36, it seems somehow better now. is it like that ??

Answer 2

[Sophia]

** the total is 99.9% **

clear all; clc;

data= load('north_x_y_lat_lon');
datacoord = reshape(data, 361,361,4);
lat = squeeze(datacoord(:,:,3));
long = squeeze(datacoord(:,:,4));

rlong = long*pi/180.;
rlat = lat*pi/180.;

load nsidc_sid_1979_2014.mat 
N1=2;

[eof_maps,pc,expv] = eof(t_u,2);

[eof_maps1,pc1,expv1] = eof(t_v,2); 

figure(1);clf;iw=1;jw=N1+2;
set(gcf,'MenuBar','none');

for i=1:iw*jw
  if i<= iw*jw-2

        C1 = squeeze(eof_maps(:,:,i));
        C2 = squeeze(eof_maps1(:,:,i));

        pc_u = pc';
        pc_v = pc1';

        subplot(iw,jw,i);
        m_proj('stereographic','lat',90,'long', 300,'radius',35,'rect','on')
        m_grid('linewi',1,'tickdir','out',...
            'xtick',[],'ytick',[])
        m_quiver(long(1:10:361,1:10:361), lat(1:10:361,1:10:361),-C1(1:10:361,1:10:361),-C2(1:10:361,1:10:361),2,'k')
        m_coast('patch',[.6 .6 .6],'edgecolor','k')
        axis on
        set(gca,'Xticklabel',[])
        set(gca,'Yticklabel',[])
        title(strcat('EOF:',num2str(i),'/',num2str(expv(i)),'%'));
    else
        subplot(iw,jw,iw*jw-1);
        plot(pc_u(:,1),'b','DisplayName','PC of u');
        hold on
        plot(pc_v(:,1),'r','DisplayName','PC of v');
        grid on
        xlabel('time')
        title('PC')
        legend(num2str([1:N1]'),2);
        box on

        subplot(iw,jw,iw*jw);
        plot(pc_u(:,2),'b','DisplayName','PC of u');
        hold on
        plot(pc_v(:,2),'r','DisplayName','PC of v');
        grid on
        xlabel('time')
        title('PC')
        legend(num2str([1:N1]'),2);
        box on

    end 

end

Answer 3

[Sophia]

the total again is 99.9%

clear all; clc;

data= load('north_x_y_lat_lon');
datacoord = reshape(data, 361,361,4);
lat = squeeze(datacoord(:,:,3));
long = squeeze(datacoord(:,:,4));

rlong = long*pi/180.;
rlat = lat*pi/180.;

load nsidc_sid_1979_2014.mat 
N1=3;

[eof_maps,pc,expv] = eof(t_u,3);

[eof_maps1,pc1,expv1] = eof(t_v,3); 

figure(1);clf;iw=1;jw=N1+3;
set(gcf,'MenuBar','none');

for i=1:iw*jw
  if i<= iw*jw-3

        C1 = squeeze(eof_maps(:,:,i));
        C2 = squeeze(eof_maps1(:,:,i));

        pc_u = pc';
        pc_v = pc1';

        subplot(iw,jw,i);
        m_proj('stereographic','lat',90,'long', 300,'radius',35,'rect','on')
        m_grid('linewi',1,'tickdir','out',...
            'xtick',[],'ytick',[])
        m_quiver(long(1:10:361,1:10:361), lat(1:10:361,1:10:361),-C1(1:10:361,1:10:361),-C2(1:10:361,1:10:361),2,'k')
        m_coast('patch',[.6 .6 .6],'edgecolor','k')
        axis on
        set(gca,'Xticklabel',[])
        set(gca,'Yticklabel',[])
        title(strcat('EOF:',num2str(i),'/',num2str(expv(i)),'%'));
    else
        subplot(iw,jw,iw*jw-2);
        plot(pc_u(:,1),'b','DisplayName','PC of u');
        hold on
        plot(pc_v(:,1),'r','DisplayName','PC of v');
        grid on
        xlabel('time')
        title('PC')
        legend(num2str([1:N1]'),2);
        box on

        subplot(iw,jw,iw*jw-1);
        plot(pc_u(:,2),'b','DisplayName','PC of u');
        hold on
        plot(pc_v(:,2),'r','DisplayName','PC of v');
        grid on
        xlabel('time')
        title('PC')
        legend(num2str([1:N1]'),2);
        box on

        subplot(iw,jw,iw*jw);
        plot(pc_u(:,3),'b','DisplayName','PC of u');
        hold on
        plot(pc_v(:,3),'r','DisplayName','PC of v');
        grid on
        xlabel('time')
        title('PC')
        legend(num2str([1:N1]'),2);
        box on

    end 

end