Pulling data from text file and the results are being shown as NaN

I am loading a text file but some of my results are being shown as NaN. This is my code:

clear all;
close all;
test=0.001;
imax=13;
kmax=4;

load('hcrdat.txt');
q=hcrdat(:,1);
d=hcrdat(:,2);
r=hcrdat(:,3);

%q=[250 250 100 50 100 25 25 25 45 70 80 30 20];
%d=[.4,.4,.3,.3,.3,.2,.2,.2,.3,.3,.3,.2,.2];
%r=[96.8,96.8,306,306,306,3098,3098,3098,306,312,306,9295,3098];

m=zeros(kmax,imax);

iter=0;
for n=1:500
    iter=iter+1;
    difmax=0;
    %DISCHARGE CORRECTIONS IN EACH LOOP
    for k=1:kmax
        sum1=0;
        sum2=0;
        for i=1:imax
            t=m(k,i);
            sum1=sum1+t*r(i)*q(i)^2;
            sum2=sum2+2*abs(t)*q(i)*r(i);
        end
        dq=-sum1/sum2;
        if abs(dq)>difmax
            difmax=abs(dq);
        end
        for i=1:imax
            q(i)=q(i)+m(k,i)*dq;
            %CHANGE OF ASSUMED DISCHARGE DIRECTION AND PROPER CORRECTIONS
            if q(i)<0
                q(i)=-q(i);
            end
            for kk=1:kmax
                m(kk,i)=-m(kk,i);
            end
        end
    end
    it=n;
    diff(it)=difmax;
    %CHECK FOR CONVERGENCE TO FINAL DISCHARGE VALUES
    if difmax<test
        break
    end
end
for i=1:imax
    % FLOW VELOCITIES IN THE VARIOUS BRANCHES
    u(i)=q(i)/1000*1.273/d(i)^2;
    % HEAD LOSSES IN EACH BRANCH
    dh(i)=r(i)*q(i)^2/1000000;
end

= = = = = = = = = = = = = = = = = = =

The data in the text file (hcrdat.txt) is:

250, .4, 96.8
250, .4, 96.8
100, .3, 306
50, .3, 306
100, .3, 306
25, .2, 3098
25, .2, 3098
25, .2, 3098
45, .3, 306
70, .3, 612
80, .3, 306
30, .2, 9295
20, .2, 3098

= = = = = = = = = = = = = = = = = = =

My results for sum1, sum2 and dq are NaN and the problem is because q is being loaded as NaN.

[José-Luis]

The easiest to get help is to post a piece of code that people can copy/paste and run, and that reproduces your problem.

Just dumping some text, without explicitly showing the error, is likely to elicit fewer responses.

[Chetan Rawal]

I didn't try to replicate the problem, but it may be due to the syntax you are using. Look at the documentation for LOAD to make sure, or use the import wizard (UIIMPORT) and generate a function from it.

[Gino]

Jose-Luis, the whole code was there but I didn't know how to post it as code (now I know), that is why I numbered listed each line of code. Thanks anyway!

P.D.: Problem solved thanks to Roger!

Answer 1

[Roger Stafford]

I see places in your code that could produce NaNs. In the section

    sum1=0;
    sum2=0;
    for i=1:imax
      t=m(k,i);
      sum1=sum1+t*r(i)*q(i)^2;
      sum2=sum2+2*abs(t)*q(i)*r(i);
    end
    dq=-sum1/sum2;

the 'm' matrix is all zeros and apparently never changes from that. Consequently all 't' values would also be zero, with the result that 'sum1' and 'sum2' would also be zero. When you do the division

    dq=-sum1/sum2;

NaNs are going to be the result and these are placed in 'difmax'.

[Gino]

Thank you Roger!