cospi

cospi(x)

Compute $\cos(\pi x)$ more accurately than cos(pi*x), especially for large x.

Examples

In the Julia programming language, the function cospi(x) is used to compute the cosine of πx more accurately than cos(pix), especially for large values ofx. Here are some common examples of its use:

1. Compute cosine for a single value:

julia> cospi(0.5)
0.0

This example computes the cosine of π/2, which is 0.

2. Compute cosine for an array of values:

julia> x = [0.25, 0.5, 0.75];
julia> cospi.(x)
3-element Array{Float64,1}:
1.0
0.0
-1.0

It computes the cosine of π times each element in the array x.

3. Compute cosine for a large value:
julia> cospi(10^6)
-1.0

This example shows that cospi can accurately compute the cosine of a large value, even with many decimal places.

Note: The cospi function is particularly useful when dealing with trigonometric calculations involving multiples of π. It provides improved accuracy compared to the standard cos(pi*x) expression.

If you encounter any issues or errors while using the cospi function, please let me know, and I'll be happy to assist you.