ENH: step 4

This commit is contained in:
Ken Martin 2005-11-10 10:50:45 -05:00
parent 814f0a573a
commit 699a97a504
6 changed files with 152 additions and 0 deletions

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project (Tutorial)
# The version number.
set (Tutorial_VERSION_MAJOR 1)
set (Tutorial_VERSION_MINOR 0)
# does this system provide the log and exp functions?
include (${CMAKE_ROOT}/Modules/CheckFunctionExists.cmake)
check_function_exists (log HAVE_LOG)
check_function_exists (exp HAVE_EXP)
# configure a header file to pass some of the CMake settings
# to the source code
configure_file (
"${PROJECT_SOURCE_DIR}/TutorialConfig.h.in"
"${PROJECT_BINARY_DIR}/TutorialConfig.h"
)
# should we use our own math functions
option(USE_MYMATH "Use tutorial provided math implementation" ON)
# add the binary tree to the search path for include files
# so that we will find TutorialConfig.h
include_directories ("${PROJECT_BINARY_DIR}")
# add the MathFunctions library?
if (USE_MYMATH)
include_directories ("${PROJECT_SOURCE_DIR}/MathFunctions")
add_subdirectory (MathFunctions)
set (EXTRA_LIBS ${EXTRA_LIBS} MathFunctions)
endif (USE_MYMATH)
# add the executable
add_executable (Tutorial tutorial.cxx)
target_link_libraries (Tutorial ${EXTRA_LIBS})
# add the install targets
install_targets (/bin Tutorial)
install_files (/include FILES "${PROJECT_BINARY_DIR}/TutorialConfig.h")
# enable testing
enable_testing ()
# does the application run
add_test (TutorialRuns Tutorial 25)
# does the usage message work?
add_test (TutorialUsage Tutorial)
set_tests_properties (TutorialUsage
PROPERTIES
PASS_REGULAR_EXPRESSION "Usage:.*number"
)
#define a macro to simplify adding tests
macro (do_test arg result)
add_test (TutorialComp${arg} Tutorial ${arg})
set_tests_properties (TutorialComp${arg}
PROPERTIES PASS_REGULAR_EXPRESSION ${result}
)
endmacro (do_test)
# do a bunch of result based tests
do_test (25 "25 is 5")
do_test (-25 "-25 is 0")
do_test (0.0001 "0.0001 is 0.01")

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add_library(MathFunctions mysqrt.cxx)
install_targets (/bin MathFunctions)
install_files (/include FILES MathFunctions.h)

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double mysqrt(double x);

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#include <stdio.h>
#include "MathFunctions.h"
#include "TutorialConfig.h"
#include <math.h>
// a hack square root calculation using simple operations
double mysqrt(double x)
{
if (x <= 0)
{
return 0;
}
double result;
// if we have both log and exp then use them
#if defined(HAVE_LOG) && defined (HAVE_EXP)
result = exp(log(x)*0.5);
fprintf(stdout,"Computing sqrt of %g to be %g using log\n",x,result);
#else
double delta;
result = x;
// do ten iterations
int i;
for (i = 0; i < 10; ++i)
{
if (result <= 0)
{
result = 0.1;
}
delta = x - (result*result);
result = result + 0.5*delta/result;
fprintf(stdout,"Computing sqrt of %g to be %g\n",x,result);
}
#endif
return result;
}

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// the configured options and settings for Tutorial
#define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
#define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@
#cmakedefine USE_MYMATH
// does the platform provide exp and log functions?
#cmakedefine HAVE_LOG
#cmakedefine HAVE_EXP

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// A simple program that computes the square root of a number
#include <stdio.h>
#include <math.h>
#include "TutorialConfig.h"
#ifdef USE_MYMATH
#include "MathFunctions.h"
#endif
int main (int argc, char *argv[])
{
if (argc < 2)
{
fprintf(stdout,"%s Version %d.%d\n",
argv[0],
Tutorial_VERSION_MAJOR,
Tutorial_VERSION_MINOR);
fprintf(stdout,"Usage: %s number\n",argv[0]);
return 1;
}
double inputValue = atof(argv[1]);
#ifdef USE_MYMATH
double outputValue = mysqrt(inputValue);
#else
double outputValue = sqrt(inputValue);
#endif
fprintf(stdout,"The square root of %g is %g\n",
inputValue, outputValue);
return 0;
}