logspace_add

eve::logspace_add = functor<logspace_add_t>

inlineconstexpr

Defined in Header

#include <eve/module/math.hpp>

Callable Signatures

namespace eve
{
   // Regular overloads
   constexpr auto logspace_add(floating_value auto x, floating_value auto ... xs)                          noexcept; // 1
   constexpr auto logspace_add(kumi::non_empty_product_type auto const& tup)             noexcept; // 2
 
   // Lanes masking
   constexpr auto logspace_add[conditional_expr auto c](/*any of the above overloads*/)  noexcept; // 3
   constexpr auto logspace_add[logical_value auto m](/*any of the above overloads*/)     noexcept; // 3
}

Parameters

* `x`, `...xs`: [real](@ref floating_value) arguments.
* `tup`: [non empty tuple](@ref kumi::non_empty_product_type) of arguments.
* `c`: [Conditional expression](@ref conditional_expr) masking the operation.
* `m`: [Logical value](@ref logical) masking the operation.

Return value

1. The call logspace_add(x, xs...) is semantically equivalent to log(exp(log(x)) + + exp(log(xs))...) without causing unnecessary overflows or throwing away too much accuracy.
2. equivalent to the call on the elements of the tuple.
3. The operation is performed conditionnaly

Example

// revision 1
#include <eve/module/math.hpp>
#include <iostream>
 
int main()
{
  eve::wide pf = {0.0, 2.0, 3.0, 30.0};
  eve::wide qf = {0.0, 1.0, 1.0, 29.56};
  eve::wide rf = {0.0, 0.5, 10.0,25.35};
  kumi::tuple wt{pf, qf};
 
  std::cout << "<- pf                                  = " << pf << "\n";
  std::cout << "<- qf                                  = " << qf << "\n";
  std::cout << "<- rf                                  = " << rf << "\n";
  std::cout << "<- wt                                  = " << wt << "\n";
 
  std::cout << "-> logspace_add(pf, qf)                = " << eve::logspace_add(pf, qf) << "\n";
  std::cout << "-> logspace_add(wt)                    = " << eve::logspace_add(wt) << "\n";
  std::cout << "-> logspace_add[ignore_last(2)](pf, qf)= " << eve::logspace_add[eve::ignore_last(2)](pf, qf) << "\n";
  std::cout << "-> logspace_add[pf != 3.0](pf, qf)     = " << eve::logspace_add[pf != 3.0](pf, qf) << "\n";
  std::cout << "-> logspace_add(pf, qf, rf)            = " << eve::logspace_add(pf, qf, rf) << "\n";
}