Resistor mesh: Difference between revisions

=={{header|Phix}}==

{{trans|BBC_BASIC}}

uses inverse() from [[Gauss-Jordan_matrix_inversion#Phix]]

and matrix_mul() from [[Matrix_multiplication#Phix]]

<lang Phix>function resistormesh(integer ni, nj, ai, aj, bi, bj)

integer n = ni*nj, k, c

sequence A = repeat(repeat(0,n),n),

B = repeat({0},n)

for i=1 to ni do

for j=1 to nj do

k = (i-1)*nj + j--1

if i=ai and j=aj then

A[k,k] = 1

else

c = 0

if i<ni then c += 1; A[k,k+nj] = -1 end if

if i>1 then c += 1; A[k,k-nj] = -1 end if

if j<nj then c += 1; A[k,k+1] = -1 end if

if j>1 then c += 1; A[k,k-1] = -1 end if

A[k,k] = c

end if

end for

end for

k = (bi-1)*nj +bj

B[k,1] = 1

A = inverse(A)

B = matrix_mul(A,B)

return B[k,1]

end function

printf(1,"Resistance = %.13f ohms\n",resistormesh(10, 10, 2, 2, 8, 7))</lang>

{{out}}

<pre>

Resistance = 1.6089912417307 ohms

</pre>