sym/subs errors

v=[];
global a
global N
global k
fplot=fopen('saida_plot','w+');

r=find(diff(subs(diff(1/(((1-a)*(log(N)/log(k)+1))+(a)*(k)),k), {N,k,a},{600,1:1:100,0.1})>=0));

for alpha=0.1:0.1:1
    r=find(diff(subs(diff(1/(((1-a)*(log(N)/log(k)+1))+(a)*(k)),k), {N,k,a},{600,1:1:100,alpha})>=0));
    if (isempty(r))
        alpha;
        v=[v,1];
        fprintf(fplot,'%d',[v,1])
    else
        v=[v,max(r)];
        fprintf(fplot,'%d',[v,max(r)])
    end
end

[Daniel]

Running the code above I got several errors:

Error using symengine

Division by zero.

Error in sym/subs>mupadsubs (line 160)

G = mupadmex('symobj::fullsubs',F.s,X2,Y2);

Error in sym/subs (line 145)

G = mupadsubs(F,X,Y);

Error in Novo (line 7)

r=find(diff(subs(diff(1/(((1-a)*(log(N)/log(k)+1))+(a)*(k)),k), {N,k,a},{600,1:1:100,0.1})>=0));

Error using symengine

Division by zero.

Error in sym/subs>mupadsubs (line 160)

G = mupadmex('symobj::fullsubs',F.s,X2,Y2);

Error in sym/subs (line 145)

G = mupadsubs(F,X,Y);

Error in Novo (line 7)

r=find(diff(subs(diff(1/(((1-a)*(log(N)/log(k)+1))+(a)*(k)),k), {N,k,a},{600,1:1:100,0.1})>=0));

As it a legacy code and newbie in matlab, would please support me ?

Answer 1

[Aniket]

Hi @Daniel,

As mentioned in error output, the issue is because of "Division by zero". The expression will cause a division by zero error if 'k' is 1, because log(1) is 0.

To ensure 'k' never takes a value of 1, range of 'k' can be changed from 1:1:100 to 2:1:100.

I hope this helps resolve the issue!