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get GPL
COST (GBP)
this unit 0.99
sub units 0.28
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1

countif

Calculates the number of elements in an array that satisfy a certain condition.

Dependents

Info

Interface

C++

Overview

The components available with this module calculate the number of elements in an array that satisfy a certain condition. The difference between the two functions consists in the way the condition is given.

Countif

 
template<class T> intcountifintn
T*data
Tcmp
bool(*fctpnt)(const T&, const T&)[function pointer] )
This function calculates the number of elements in an array that satisfy a certain predicate given as argument. The predicate is a user-defined function that takes as first argument each element of the array and as second argument the value of <em> cmp </em>. Three predicate functions are available with this module to provide basic relational operators, tests to see if two values are equal, or whether one is greater/lesser than the other.

Example:

#include <iostream>
#include <codecogs/stats/countif.h>
 
int main()
{
  int x[12] = {3, 5, 1, 2, 6, 8, 10, 2, 2};
  std::cout << "The number of elements equal to 2 is: ";
  std:: cout << Stats::countif<int>(12, x, 2, Stats::isEqual);
  std::cout << std::endl;
  std::cout << "The number of elements greater than 3 is: ";
  std::cout << Stats::countif<int>(12, x, 3, Stats::isGreater);
  std::cout << std::endl;
  std::cout << "The number of elements less than 7 is: ";
  std::cout << Stats::countif<int>(12, x, 7, Stats::isLess);
  std::cout << std::endl;
  return 0;
}

Output:

The number of elements equal to 2 is: 3
The number of elements greater than 3 is: 4
The number of elements less than 7 is: 10

Authors

Lucian Bentea (September 2005)
Source Code

Source code is available when you agree to a GP Licence or buy a Commercial Licence.

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Countif

 
intcountifintn
int*data
const char*cmp )
This function calculates the number of <em> integers </em> in an array that satisfy a certain predicate given as argument. The predicate is given as a character string, with the following syntax: the first character is one of "=", "!", ">" or "<" to provide the relation that needs to be satisfied, where "!" means inequality. The next characters are used to specify the integer (signed or unsigned) to which the value of each element of the array is to be compared.

Example:

#include <iostream>
#include <codecogs/stats/countif.h>
 
int main()
{
  int x[12] = {3, 5, 1, 2, 6, 8, 10, 2, 2};
  std::cout << "The number of elements equal to 2 is: ";
  std::cout << Stats::countif(12, x, "=2");
  std::cout << std::endl;
  std::cout << "The number of elements greater than 3 is: ";
  std::cout << Stats::countif(12, x, ">3");
  std::cout << std::endl;
  std::cout << "The number of elements less than 7 is: ";
  std::cout << Stats::countif(12, x, "<7");
  std::cout << std::endl;
  return 0;
}

Output:

The number of elements equal to 2 is: 3
The number of elements greater than 3 is: 4
The number of elements less than 7 is: 10

Parameters

cmpConstant
Source Code

Source code is available when you agree to a GP Licence or buy a Commercial Licence.

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