Difference between revisions of "Calculate the sum over a container"

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{{Infobox See Also Math}}
 +
This code demonstrates how to calculate the sum of a container (most often an array or similar structure).
 +
 +
==See also==
 +
* [[Perform simple mathematical operations on two matrices]]
 +
* [[:Category:Arrays]]
 +
 
==Implementations==
 
==Implementations==
===C===
+
 
Total of a series function. Terminate by using INT_MAX
+
===Algol 68===
 +
 
 +
The following function computes the sum of the elements of the array passed to it. The type of the array elements is called <TT>NUM</TT>, which can be defined as any suitable integer or real type.
 +
 
 
<pre>
 
<pre>
//stdarg.h must be included for this type of function to be declared
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MODE NUM = INT; # type of array element #
#include <stdarg.h>
+
  
int total( int first, ... ) {
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PROC sum = ([] NUM a) NUM :
  int count = 0, sum = 0, i = first;
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    BEGIN
  va_list marker;
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        NUM result := 0;
 +
        FOR i FROM LWB a TO UPB a DO
 +
            result +:= a[i]
 +
        OD;
 +
        result
 +
    END
 +
</pre>
  
  va_start( marker, first );    /* Initialize variable arguments. */
+
For instance, the call
  while( i != INT_MAX )
+
 
  {
+
<pre>
      sum += i;                  //increases the sum
+
sum((3, 4, 5, 6))
      i = va_arg( marker, int);  //Gets the next argument
+
  }
+
  va_end( marker );              // Resets the list
+
  return sum;
+
}
+
 
</pre>
 
</pre>
 +
returns 18.
  
 
===Assembly===
 
===Assembly===
Line 38: Line 49:
 
</pre>
 
</pre>
  
 +
===C===
 +
<pre class="c">
 +
int total( int numbers[], int size ) {
 +
  int sum = 0, i;
 +
  for ( i = 0 ; i < size ; i++ )
 +
  {
 +
      sum += numbers[i];
 +
  }
 +
  return sum;
 +
}
 +
</pre>
  
===Java===
+
===C++===
 +
<pre class="cpp">
 +
#include<numeric>
 +
 
 +
sum = std::accumulate(coll.begin(),coll.end(),0);
 +
</pre>
 +
 
 +
===Common Lisp===
 +
<pre class="lisp">
 +
(reduce #'+ list)
 +
(reduce #'+ list :initial-value 0) ; improved version that also works with empty lists
 +
</pre>
 +
 
 +
Another way:
 +
 
 +
<pre class="lisp">
 +
(apply #'+ list)
 +
</pre>
 +
 
 +
===Erlang===
 
<pre>
 
<pre>
 +
lists:sum(List).
 +
</pre>
 +
 +
===Excel===
 +
<pre>
 +
=SUM([cells])
 +
</pre>
 +
 +
===F#===
 +
<pre class="fsharp">
 +
Seq.sum container
 +
</pre>
 +
 +
===Haskell===
 +
<pre class="haskell">
 +
sum container
 +
</pre>
 +
For example:
 +
<pre>
 +
Prelude> sum [1, 2, 3, 4]
 +
10
 +
</pre>
 +
 +
===Java===
 +
<pre class="java">
 
import java.util.*;
 
import java.util.*;
  
Line 47: Line 113:
 
     public static int total(int... values) {
 
     public static int total(int... values) {
 
         int total = 0;
 
         int total = 0;
         for (int i : values) {
+
         for (int i : values) total += i;      
            if (i == Integer.MAX_VALUE) break;
+
            total +=i;
+
        }
+
     
+
 
         return total;
 
         return total;
 
     }
 
     }
Line 57: Line 119:
 
     public static void main(String[] args) {
 
     public static void main(String[] args) {
  
         System.out.printf("Total: %d: ", total(1,2,4,40,Integer.MAX_VALUE));
+
         System.out.println("Total: %d: ", total(1,2,4,40));
 
          
 
          
 
     }
 
     }
Line 68: Line 130:
 
# let sum = List.fold_left ( + ) 0;;
 
# let sum = List.fold_left ( + ) 0;;
 
val sum : int list -> int = <fun>
 
val sum : int list -> int = <fun>
<pre>
 
For example:
 
 
</pre>
 
</pre>
 +
For example:
 +
<pre>
 
# sum [1; 2; 4; 40];;
 
# sum [1; 2; 4; 40];;
 
- : int = 47
 
- : int = 47
 +
</pre>
 +
 +
===Perl===
 +
<pre class="perl">
 +
use List::Util qw(sum);
 +
sum @arr;
 +
sum 0, @arr; # improved version that also works with empty arrays
 
</pre>
 
</pre>
  
 
===Python===
 
===Python===
 
A function that sums the values in a sequence is built into python, its name is 'sum'.
 
A function that sums the values in a sequence is built into python, its name is 'sum'.
<pre>
+
<pre class="python">
if __name__ == '__main__':
+
assert sum([1,2,3]) == 6
  assert sum([1,2,3]) == 6
+
 
</pre>
 
</pre>
A parallel to the ANSI C example given above is as follows:
 
<pre>
 
import itertools
 
def total(*values):
 
  return sum(itertools.takewhile(sys.maxint.__cmp__, values))
 
  
if __name__ == '__main__':
+
===Ruby===
   assert total(1,2,3,sys.maxint) == 6
+
<pre class="ruby">
 +
class Array
 +
   def sum
 +
    inject { |s, v| s += v }
 +
  end
 +
end
 
</pre>
 
</pre>
 +
Or more concisely,
 +
<pre class="ruby">
 +
class Array
 +
  def sum
 +
    reduce(:+)
 +
  end
 +
end
 +
</pre>
 +
 +
===Scheme===
 +
<pre class="scheme">
 +
(apply + list)
 +
</pre>
 +
 +
===Tcl===
 +
<pre class="tcl">
 +
proc sum list {expr ([join $list +])}
 +
</pre>
 +
 +
===Zsh===
 +
<pre>
 +
zsum() {
 +
local -a array
 +
array=(1 2 3 4 5)
 +
(( sum=${(j:+:)array} ))
 +
return sum
 +
}
 +
</pre>
 +
 
[[Category:Math]]
 
[[Category:Math]]
[[Category:C]]
+
[[Category:Arrays]]
 +
 
 +
[[Category:Algol 68]]
 
[[Category:Assembly]]
 
[[Category:Assembly]]
 +
[[Category:C]]
 +
[[Category:C++]]
 +
[[Category:Common Lisp]]
 +
[[Category:Erlang]]
 +
[[Category:Excel]]
 +
[[Category:F sharp]]
 +
[[Category:Haskell]]
 
[[Category:Java]]
 
[[Category:Java]]
[[Category:Python]]
 
 
[[Category:Objective Caml]]
 
[[Category:Objective Caml]]
 +
[[Category:Perl]]
 +
[[Category:Python]]
 +
[[Category:Ruby]]
 +
[[Category:Scheme]]
 +
[[Category:Tcl]]
 +
[[Category:Zsh]]

Latest revision as of 15:50, 10 August 2012

Related content:

This code demonstrates how to calculate the sum of a container (most often an array or similar structure).

See also[edit]

Implementations[edit]

Algol 68[edit]

The following function computes the sum of the elements of the array passed to it. The type of the array elements is called NUM, which can be defined as any suitable integer or real type.

MODE NUM = INT; # type of array element #

PROC sum = ([] NUM a) NUM :
    BEGIN
        NUM result := 0;
        FOR i FROM LWB a TO UPB a DO
            result +:= a[i]
        OD;
        result
    END

For instance, the call

sum((3, 4, 5, 6))

returns 18.

Assembly[edit]

INT_MAX = 2147483647.

sum proc
	mov ecx,DWORD PTR [esp]
	add esp,4
	xor eax,eax
	sum_loop1:
	add eax,DWORD PTR [esp]
	add esp,4
	cmp DWORD PTR [esp],2147483647
	jne sum_loop1
	mov DWORD PTR [esp],ecx
	ret
sum endp

C[edit]

int total( int numbers[], int size ) {
   int sum = 0, i;
   for ( i = 0 ; i < size ; i++ )
   {
      sum += numbers[i];
   }
   return sum;
}

C++[edit]

#include<numeric>

sum = std::accumulate(coll.begin(),coll.end(),0);

Common Lisp[edit]

(reduce #'+ list)
(reduce #'+ list :initial-value 0) ; improved version that also works with empty lists

Another way:

(apply #'+ list)

Erlang[edit]

lists:sum(List).

Excel[edit]

=SUM([cells])

F#[edit]

Seq.sum container

Haskell[edit]

sum container

For example:

Prelude> sum [1, 2, 3, 4]
10

Java[edit]

import java.util.*;

public class Total {

    public static int total(int... values) {
        int total = 0;
        for (int i : values) total += i;       
        return total;
    }

    public static void main(String[] args) {

        System.out.println("Total: %d: ", total(1,2,4,40));
        
    }
}

OCaml[edit]

Summing is a special case of folding the addition operator starting with zero:

# let sum = List.fold_left ( + ) 0;;
val sum : int list -> int = <fun>

For example:

# sum [1; 2; 4; 40];;
- : int = 47

Perl[edit]

use List::Util qw(sum);
sum @arr;
sum 0, @arr; # improved version that also works with empty arrays

Python[edit]

A function that sums the values in a sequence is built into python, its name is 'sum'.

assert sum([1,2,3]) == 6

Ruby[edit]

class Array
  def sum
    inject { |s, v| s += v }
  end
end

Or more concisely,

class Array
  def sum
    reduce(:+)
  end
end

Scheme[edit]

(apply + list)

Tcl[edit]

proc sum list {expr ([join $list +])}

Zsh[edit]

zsum() {
	local -a array
	array=(1 2 3 4 5)
	(( sum=${(j:+:)array} ))
	return sum
}