Check whether symbolic array elements are infinite
isinf(A) returns an array of the same size as A containing logical 1s (true) where the elements of A are infinite, and logical 0s (false) where they are not. For a complex number, isinf returns 1 if the real or imaginary part of that number is infinite or both real and imaginary parts are infinite. Otherwise, it returns 0.
Using isinf, determine which elements of this symbolic matrix are infinities:
isinf(sym([pi NaN Inf; 1 + i Inf + i NaN + i]))
ans = 0 0 1 0 1 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 infinite:
ans = [ Inf, Inf, Inf, Inf] ans = 1 1 1 1
Nevertheless, the cotangents of the approximated values are not infinite due to the round-off errors:
ans = 0 0 0 0
Input value, specified as a symbolic number, variable, expression, or function, or as an array, vector, or matrix of symbolic numbers, variables, expressions, functions.