\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)
speed_program.cpp¶
View page sourceExample Use of SpeedTest¶
Program¶
# include <cppad/utility/speed_test.hpp>
// Some compilers have gotten smarter and do not calucate somthing that is not used
// so make the result a global.
double global_result = 0.0;
std::string Test(size_t size, size_t repeat)
{ // setup
double *a = new double[size];
double *b = new double[size];
size_t i = size;;
while(i)
{ --i;
a[i] = double(i);
b[i] = double(2 * i);
}
// operations we are timing
while(repeat--)
{ i = size;;
while(i)
{ --i;
global_result += a[i] * b[i];
}
}
// teardown
delete [] a;
delete [] b;
// return a test name that is valid for all sizes and repeats
return "double: result = sum_i a[i] * b[i]";
}
int main(void)
{
CppAD::SpeedTest(Test, 20, 20, 100);
return 0;
}
Output¶
Executing of the program above generated the following output (the rates will be different for each particular system):
double: c[*] = a[*] + b[*]
size = 20 rate = 7,157,515
size = 40 rate = 3,887,214
size = 60 rate = 2,685,214
size = 80 rate = 2,032,124
size = 100 rate = 1,657,828