Check whether symbolic array elements are finite
Using isfinite
, determine
which elements of this symbolic matrix are finite values:
isfinite(sym([pi NaN Inf; 1 + i Inf + i NaN + i]))
ans = 2×3 logical array 1 0 0 1 0 0
Approximate these symbolic values with the 50-digit accuracy:
V = sym([pi, 2*pi, 3*pi, 4*pi]); V_approx = vpa(V, 50);
The cotangents of the exact values are not finite:
cot(V) isfinite(cot(V))
ans = [ Inf, Inf, Inf, Inf] ans = 1×4 logical array 0 0 0 0
Nevertheless, the cotangents of the approximated values are finite due to the round-off errors:
isfinite(cot(V_approx))
ans = 1×4 logical array 1 1 1 1
For any A
, exactly one of the
three quantities isfinite(A)
, isinf(A)
,
or isnan(A)
is 1
for each element.
Elements of A
are recognized
as finite if they are
Not symbolic NaN
Not symbolic Inf
or -Inf
Not sums or products containing symbolic infinities Inf
or -Inf