MATLAB: Hi,,is there anyone who could suggest any way of calculating the weight of a matrix row-wise

binary matrix weight

Example,,say I have a matrix

 A=[1 0 0 1;
    0 1 0 1; 
    1 1 1 1; 
    1 1 0 1]

how do I calculate that how many rows have one 1's? how many have two 2's and so on?

Best Answer

with

h=histogram(sum(A,2),[0:5])
count=h.Values
     0     0     2     1     1

you have the result in the variable count, reading:

0 rows have null '1', 0 rows have one '1', 2 rows have two '1', 1 row has three '1' and 1 row has four '1'.

the histogram field to the right, filled with [0:5] defines the histogram bin edges: 4 bins need 5 edges.

If you find this answer of any help solving your question,

please click on the thumbs-up vote link, or mark it as accepted answer

thanks in advance

John

jgb2012@sky.com

Related Solutions

MATLAB: Sort rows based on number of 1’s in each row.

>> A = [1,1,0,1;1,0,0,0;1,0,1,0;1,1,1,1];
>> [~,idx] = sort(sum(A,2),'descend');
>> A(idx,:)
ans =
   1   1   1   1
   1   1   0   1
   1   0   1   0
   1   0   0   0

MATLAB: Interpolate gridded matrix row-wise

Normally you could achieve this easily by interpolating over rows with a function that does not extrapolate by default. I believe interp1 could do this (?). I used a slighly more messy approach, where I drew a polygon around the area of interest, filled all nans, then removed all points outside of the polygon.

Z = sst_up_574;
X = Y1;
Y = Ydepth;
%Scan rows and find first non-NaN
x = nan(size(X,1))
y = nan(size(Y,1))
for j = 1:size(Z,1)
    [~,c] = find(~isnan(Z(j,:))==true,1,'first');
    if ~isempty(c)
        x(j) = X(j,c);
        y(j) = Y(j,c);
    else
        x(j) = max(X(j,:));
        y(j) = max(Y(j,:));
    end
end
x(isnan(x))=[];
y(isnan(y))=[];
%Build a polygon
x = [x 0];
y = [y min(Y(:))]
%Find points inside of polygon
in = inpolygon(X(:),Y(:),x,y);
%Fill all NaNs
Zq = fillmissing(Z,'linear',2);
%Set values outside of polygon to NaN
Zq(~in) = NaN;
figure(1)
pcolor(X,Y,Zq); shading flat
set(gca,'Ydir','reverse')
set(gca,'xlim',[bin(1) bin(91)],...
    'ylim',[0 500],'fontsize',8,'xminortick','on','yminortick','on')
hold on
hc = colorbar;
rmap=jet(20);
newmap=rmap(2:1:20,:);
colormap(newmap);
caxis([4 23]);
grid on;
box on
set(gca,'Fontweight','bold','Fontsize',16);
set(get(hc,'ylabel'),'string','Water Temperature (^oC)','rotation',270,'verticalalignment','bottom');
ylabel('Depth (m)');
xlabel('Date');
title(['Water Temperature: Upstream SG574'], 'fontweight', 'bold','FontSize',18)

Best Answer

Related Solutions

MATLAB: Sort rows based on number of 1’s in each row.

MATLAB: Interpolate gridded matrix row-wise

Related Question