Algorithm (Workflow)

This function, isint32, determines if a given number a is an integer without a fractional part, specifically within the limits of an int32 data type.

Input Parameters

• a: A number that needs to be checked if it is an integer.

Output Results

• b: A boolean value. It returns true if the number a has no fractional part, i.e., it is an integer. Otherwise, it returns false.

Algorithm Explanation

The function uses the mod function to determine if the number a has a fractional part. The expression mod(a, (1-1e-18)) calculates the remainder of a when divided by a value slightly less than 1. This is done to account for floating-point precision issues.

The result of mod(a, (1-1e-18)) is then compared to a small threshold value, 1e-9. If the remainder is less than 1e-9, it is considered negligible, and the function returns true, indicating that a is effectively an integer.

This method is faster than using isequal(rem(a,1),0) because it avoids the overhead of the rem function and directly checks for a negligible remainder.

The function is particularly useful in scenarios where the number of edges needs to be calculated, as indicated in the example usage: if ~isint32(nf); nf=nofrd(R,nf/2); end;