Cleaned up the code using Loops clear // Chinese Remainder Theorem (CRT) for 3 congruence equations// e.g. x ≡ 3 mod 5; x ≡ 1 mod 7; x ≡ 6 mod 8// result ≡ 78 mod 280 m=evstr(x_dialog(['Moduli values: '],'1'));a=evstr(x_dialog(['Remainder values: '],'1'));m1=m(1); m2=m(2); m3=m(3);a1=a(1); a2=a(2); a3=a(3);n=evstr(x_dialog(['Number of iterations: '],'1')); M=prod(m); for i=1:length(m) M_ratio(i) = M/m(i)end for i=1:length(m) for j=1:n if modulo(((M_ratio(i)*j)-1),m(i)) == 0 M_inv(i)=j; xn(i)=(a(i)*M_ratio(i)*M_inv(i)); end endend x = modulo(sum(xn),M) // Console output://mprintf('\nThe solution for (x): %d mod %d',x, M) messagebox(['x ≡ '+string(a1)'+' mod '+string(m1)' ... 'x ≡ '+string(a2)'+' mod '+string(m2)' ... 'x ≡ '+string(a3)'+' mod '+string(m3)' ... 'The solution for (x): '+string(x)+' mod '+string(M)'], ... 'Solution of 3 congruence equations')
On Sat, 30 Apr 2022 at 06:14, Lester Anderson <arctica1...@gmail.com> wrote: > Hello all, > > I have a simple code which computes applies the Chinese Remainder theorem > (for a single variable) given three input congruence equations to solve for > x; not very elegant but it works: > > My query, is it possible to make this more generalised and vary the number > of input equations and give the user an option to specify the number of > equations? > For example, one may have 2, 4 or more equations. > > Any pointers would be helpful. > > Thanks > Lester > > clear > // Chinese Remainder Theorem (CRT) for 3 congruence equations// e.g. x ≡ 3 > mod 5; x ≡ 1 mod 7; x ≡ 6 mod 8// result ≡ 78 mod 280 > m=evstr(x_dialog(['Moduli values: '],'1'));r=evstr(x_dialog(['Remainder > values: '],'1'));m1=m(1); m2=m(2); m3=m(3);r1=r(1); r2=r(2); > r3=r(3);n=evstr(x_dialog(['Number of iterations: '],'1')); > M=m1*m2*m3;M1=M/m1; M2=M/m2; M3=M/m3; > for i=1:n > if modulo(((M1*i)-1),m1) == 0 then > M1_inv=i; > end > > if modulo(((M2*i)-1),m2) == 0 then > M2_inv=i; > end > > if modulo(((M3*i)-1),m3) == 0 then > M3_inv=i; > endend > x1=(r1*M1*M1_inv);x2=(r2*M2*M2_inv);x3=(r3*M3*M3_inv); > x = modulo((x1 + x2 + x3), M); > messagebox(['x ≡ '+string(r1)'+' mod '+string(m1)' ... > 'x ≡ '+string(r2)'+' mod '+string(m2)' ... > 'x ≡ '+string(r3)'+' mod '+string(m3)' ... > 'The solution for (x): '+string(x)+' mod '+string(M)'], > ... > 'Solution of 3 congruence equations') > > > > > >
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